tag:theconversation.com,2011:/global/topics/allergies-384/articlesAllergies – The Conversation2024-03-27T13:27:00Ztag:theconversation.com,2011:article/2257282024-03-27T13:27:00Z2024-03-27T13:27:00ZHoney is said to help with hay fever symptoms – here’s what the research says about this claim<figure><img src="https://images.theconversation.com/files/584039/original/file-20240325-22-41zped.jpg?ixlib=rb-1.1.0&rect=8%2C0%2C5742%2C3828&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Recent investigations into honey's allergy-alleviating potential have yielded intriguing results.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/positive-young-woman-honey-kitchen-1009425373">Africa Studio/ Shutterstock</a></span></figcaption></figure><p>Honey has a long history as a revered natural remedy across many cultures. Ancient civilisations recognised its therapeutic potential, employing it for various medicinal purposes. The ancient Egyptians, Assyrians, Chinese, Greeks and Romans, for instance, used it to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758027/#:%7E:text=of%20natural%20honey-,Human%20use%20of%20honey%20is%20traced%20to%20some%208000%20years,of%20the%20gut%20(12).">heal wounds</a>. And many cultures today continue to use it as a remedy for <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5424551/">sore throats and coughs</a>.</p>
<p>Some people also assert that honey can alleviate hay fever symptoms. Advocates of this method claim honey can help thanks to its purported <a href="https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2020.599080/full">anti-inflammatory and anti-allergic properties</a> (though empirical evidence for this is lacking).</p>
<p>But what does science actually say about this <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758027/">age-old remedy</a>? Recent investigations into honey’s potential for <a href="https://core.ac.uk/download/pdf/48853226.pdf">alleviating hay fever</a> symptoms have yielded <a href="https://www.annsaudimed.net/doi/full/10.5144/0256-4947.2013.469">intriguing findings</a> that certainly warrant further exploration. </p>
<p>One fascinating aspect being investigated is honey’s ability to act as a form of <a href="https://core.ac.uk/download/pdf/48853226.pdf">immunotherapy</a> – a treatment strategy that aims to modify the immune system’s response to allergens.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/books/NBK279487/">Immunotherapy</a> involves exposing the immune system to gradually increasing doses of allergens, such as pollen, in a controlled manner. This exposure helps <a href="https://www.sciencedirect.com/science/article/pii/S108112062031214X">desensitise the immune system over time</a>, reducing its hypersensitivity and lessening allergic reactions. </p>
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Read more:
<a href="https://theconversation.com/hay-fever-how-immunotherapy-can-help-sufferers-not-getting-relief-from-the-usual-treatments-204945">Hay fever: how immunotherapy can help sufferers not getting relief from the usual treatments</a>
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<p>For instance, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6074882/">one study</a> found that people who consumed local honey daily for four weeks alongside an allergy tablet had significant improvements in their hay fever symptoms compared to those who only took an allergy tablet.</p>
<p>Honey’s <a href="https://link.springer.com/article/10.1186/s12906-020-03170-5">anti-inflammatory properties</a> are of considerable interest when it comes to hay fever. Honey contains various bioactive compounds, including <a href="https://www.sciencedirect.com/science/article/pii/S0271531710001715?casa_token=SA2rSuXhWicAAAAA:SfwGGe6S1RS4zsbSzWtiTwqLkvVzJMxKDYyRiGyHKTIrEfSvQz7mrO1VjfILxhXZvWOiwyXUHyc">flavonoids and phenolic acids</a>, which exhibit anti-inflammatory effects. These compounds work by preventing inflammation in the body, which may help reduce many of the symptoms caused by an allergic reaction (such as a stuffy or runny nose).</p>
<p>Honey also boasts a <a href="https://www.sciencedirect.com/science/article/pii/S096399692031111X?casa_token=lkdrP9Isd7cAAAAA:GGAlThdW4PL0Uhe9tHgvqoxxtqWaYDYgprpW-g6yVJT-U-_tceJEV3dF_sLpim8eeEIzMesN_M8">rich array of antioxidants</a>, such as polyphenols. These antioxidants scavenge harmful free radicals – unstable molecules that may damage cells and trigger inflammation. By neutralising free radicals, honey may help protect cells and tissues from damage, reducing allergic inflammation (and allergy symptoms).</p>
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<img alt="A young girl standing outside in a field of flowers holds a jar and a spoonful of honey." src="https://images.theconversation.com/files/584041/original/file-20240325-16-zvddmg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/584041/original/file-20240325-16-zvddmg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/584041/original/file-20240325-16-zvddmg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/584041/original/file-20240325-16-zvddmg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/584041/original/file-20240325-16-zvddmg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/584041/original/file-20240325-16-zvddmg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/584041/original/file-20240325-16-zvddmg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Certain types of honey may be more beneficial than others.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/child-eats-honey-summer-photo-selective-1786699142">Tatevosian Yana/ Shutterstock</a></span>
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<p>Honey also has prebiotic characteristics, which may further explain their potential in managing hay fever symptoms. Prebiotics are substances that promote the growth and activity of beneficial gut bacteria, enhancing gut health. Emerging evidence suggests that <a href="https://www.frontiersin.org/articles/10.3389/fnut.2022.957932/full">honey’s prebiotic properties</a> may change the composition and function of the gut microbiota.</p>
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Read more:
<a href="https://theconversation.com/hay-fever-could-be-linked-to-our-gut-and-nose-bacteria-and-probiotics-may-help-symptoms-203855">Hay fever could be linked to our gut and nose bacteria – and probiotics may help symptoms</a>
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<p>A healthy gut microbiota is essential for <a href="https://www.mdpi.com/2304-8158/11/14/2102">maintaining a balanced immune system</a> and preventing aberrant immune responses – including allergic reactions. By promoting the growth of beneficial gut bacteria and bolstering gut function, honey may indirectly influence how severely we react to seasonal pollen.</p>
<h2>What to consider</h2>
<p>Not all honey is created equal. Where it’s sourced and how it’s processed may affect its <a href="https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2021.642836/full">therapeutic potential</a>. </p>
<p>Raw honey, which undergoes minimal processing and retains more of its natural compounds, is often favoured for its potential health benefits.</p>
<p>Honey’s composition can also vary depending on the types of plants visited by the bees. Monofloral honey, derived primarily from the nectar of a single plant species, may contain <a href="https://www.sciencedirect.com/science/article/pii/S0271531702004062?casa_token=BkuFSyKQ8fQAAAAA:IkGedKDhNQpx03zchlKjkbvIjEacHhCyqC_H-7BarkV_VMnyBKq2rpOI1_RQH0q8GXfL0ux_SrA">specific compounds</a> that offer therapeutic advantages over polyfloral varieties (derived from multiple plant species). </p>
<p>If you’re thinking about using honey to help with your hay fever symptoms, it’s important to take into account certain practical considerations and exercise caution.</p>
<p><a href="https://www.annsaudimed.net/doi/full/10.5144/0256-4947.2013.469">Research recommends</a> consuming 1g of honey per kilogram of body weight each day in order to have any affect. For a person weighing 80kg, this would translate to four tablespoons of honey daily. Studies also recommend taking honey <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7870997/">before and throughout</a> hay fever season in order to have the most benefit on symptoms.</p>
<p>It’s important to note that honey may not be suitable for everyone. Children under the age of one should not consume honey due to the <a href="https://accpjournals.onlinelibrary.wiley.com/doi/abs/10.1592/phco.22.16.1479.33696?casa_token=YuEegd3p17MAAAAA:JW_bI1PQQsVXBClNRnrl9VHrxXDLlgVDUMmhMeaE2zixEkgEuF-C7AQxLPVg0DvVFPA6xGCij-4HdGvy">risk of botulism</a>, a rare but serious illness. People with severe hay fever or asthma should speak with their GP before using honey, as <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1398-9995.1992.tb02248.x">allergic reactions</a> to bee products can be severe.</p>
<p>While honey shows promise in managing hay fever symptoms, it should complement, rather than replace, <a href="https://www.nhs.uk/conditions/hay-fever/">conventional therapies</a> prescribed by your doctor since it may not work equally well for everyone. If you’re experiencing severe hay fever symptoms, it’s unlikely honey will provide sufficient relief.</p><img src="https://counter.theconversation.com/content/225728/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Honey has long been used as a natural remedy for many ailments.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2258112024-03-25T13:05:21Z2024-03-25T13:05:21ZNasal rinsing: why flushing the nasal passages with tap water to tackle hay fever could be fatal<figure><img src="https://images.theconversation.com/files/581897/original/file-20240314-16-vdod90.jpg?ixlib=rb-1.1.0&rect=40%2C33%2C4452%2C2957&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/girl-rinses-her-nose-saline-solution-2249907389">Zaruna/Shutterstock</a></span></figcaption></figure><p>Nasal rinsing or irrigation is an increasingly popular technique to manage hay fever and other irritants in the nose. It involves pouring or squirting a solution into the nose to help wash out microbes, mucus and other debris such as dust or allergens.</p>
<p>There are specialised containers called neti pots that are used to pour water into one nostril, allowing it to run out of the other by tilting your head to the side. Water bottles and other specialised sprays pre-filled with saline solution can also be used.</p>
<p>But the practice is not without its risks, not least because if not done with sterile water it can introduce germs into the body. A small number of people, especially those with weakened immune systems, have even died from diseases caught through nasal rinsing. </p>
<p>So how can allergy sufferers reap the benefits of nasal rinsing while avoiding the pitfalls?</p>
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<p>Rinsing the nasal passages with any liquid – sterile or otherwise – may increase the risk of infection. The nose is home to a host of microbes, which help <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7763594/">protect body surfaces</a>. Rinsing may remove or kill these good microbes, providing an opportunity for pathogens to enter the body.</p>
<p>However, the biggest risk comes from germs that might be in the liquid – so any fluid poured into the nose should be sterile. The sterile nasal sprays available widely from pharmacies, for example, are not associated with this risk. But tap water is not sterile.</p>
<p>A <a href="https://wwwnc.cdc.gov/eid/article/30/4/23-1076_article">recent study</a> identified ten people who had undertaken nasal rinsing in the US and contracted <a href="https://www.cdc.gov/parasites/acanthamoeba/index.html"><em>acanthamoeba amebae</em></a>. While the risk is low for most healthy people, infection with this parasite can be fatal for people with weakened immune systems. Three of the ten people in the study died, but another study found <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9835757/">82% of US cases of the infection are fatal</a>. </p>
<p>Another amoeba found widely in our environment is <a href="https://www.ncbi.nlm.nih.gov/books/NBK535447/"><em>naegleria fowleri</em></a>, which has a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7275226/">97% fatality rate</a>
in detected cases – even for otherwise healthy people. Thankfully cases of infection from this parasite are rare too, but using <a href="https://academic.oup.com/cid/article/55/9/e79/434487">tap water for nasal rinsing</a> and fresh water swimming have been linked to infection. </p>
<p>It is also likely that infections and deaths are much higher in countries where access to clean water is limited. </p>
<p>The US study may have been small but others have found dangerous assumptions about the use of tap water in medical devices. Research conducted in the <a href="https://wwwnc.cdc.gov/eid/article/29/2/22-1205_article">US in 2021</a> found that 50% of people thought tap water was fine for nasal rinsing – and cleaning contact lenses (another dangerous mistake).</p>
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<h2>Why is the nose a danger zone?</h2>
<p>Blood vessels are close to the surface in the nose and sinuses making it easier for pathogens to enter the blood stream. The <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3573758/">vessels also dilate</a> when inflamed due to allergies bringing them even closer to the surface, increasing infection risk, especially if they rupture.</p>
<p>These blood vessels drain an area known as the “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4298578/">danger triangle</a> of the face” – between the edges of the mouth and the top of the nose, between the eyes. The veins from this region run back into the skull and connect with the vessels that drain the brain, providing a pathway for microbes to travel from the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4298578/">sinuses into the brain</a> where they can cause serious infections and potentially even death. </p>
<p>Such cases typically begin as brain inflammation or rhinosinusitis, as seen in the study, which can progress to a <a href="https://www.nhs.uk/conditions/cavernous-sinus-thrombosis/causes/">cavernous sinus thrombosis</a>. </p>
<p>This is when any infection, such as sinusitis or a spot on the face, spreads into the cavernous sinus, which drains blood from the brain. As a <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/752332">defence mechanism</a> the body attempts to <a href="https://journals.lww.com/em-news/blog/thecasefiles/lists/posts/post.aspx?ID=68">stop the infection spreading</a> by forming a clot to reduce blood flow from the brain, increasing pressure.</p>
<h2>It’s not just the nose</h2>
<p>The nasal passages include more than just tubes that run down to the back of the throat. The tubes connecting from the ear, known as the <a href="https://www.ncbi.nlm.nih.gov/books/NBK482338/">eustachian tubes</a>, open into the back of the nose on either side. Also attached to these are a number of sinuses, which are blind-ended spaces that serve a variety of functions. </p>
<p>For example, they reduce the weight of the skull, give a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5423803/">buffer zone for trauma</a> to the face and provide an increased surface area to warm and moisten inhaled air. The nasal passages, then, are much more expansive than it might seem. </p>
<p>Their close proximity to other structures is the reason, for instance, that the forehead, eyes and teeth hurt during a cold. Nasal passages are located near the nerves that supply the teeth and these spaces fill with mucous and become generally <a href="https://pubmed.ncbi.nlm.nih.gov/14552231/">inflamed and painful</a>.</p>
<p>This also means that allergens and microbes can work their way <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5108620/">into these areas</a> too. </p>
<p>These <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3906518/">spaces are lined</a> by a special type of epithelium – the tissue that covers all body surfaces. Epithelium contains <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199822/">cells that produce mucus and have hairs</a>, called cilia, on their surface.</p>
<p>These are two of the body’s mechanisms to try and keep germs out of the body. The mucus acts like a glue to catch them so the cilia can move them down the nasal passages to a place where they can be blown free of the body, picked out of the nose, or swallowed.</p>
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<h2>Who should avoid nasal rinsing?</h2>
<p>Those with any kind of sinus or ear infection should avoid nasal irrigation until it has cleared up. Rinsing can increase the pressure in the ear tube or spread pathogens into other areas where they may cause further infection or discomfort.</p>
<p>Those with already dry nasal passages or sinuses may find that irrigation can exacerbate the problem. This is because, as it evaporates, the liquid can remove some of the body’s natural protective lubrication. </p>
<p>If nasal rinsing sounds like something that may be helpful, ensure you use sterile saline solution. If you must rinse with tap water, it should be boiled and allowed to cool before use.</p><img src="https://counter.theconversation.com/content/225811/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Nasal rinsing might seem like an effective home remedy for allergies but there are risks.Adam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2251072024-03-22T16:20:40Z2024-03-22T16:20:40ZWater allergy: a debilitating but thankfully rare condition<figure><img src="https://images.theconversation.com/files/582008/original/file-20240314-18-dpj1lj.jpg?ixlib=rb-1.1.0&rect=32%2C21%2C7199%2C4803&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/shower-head-dark-dramatic-scary-light-2411764133">Tero Vesalainen/Shutterstock</a></span></figcaption></figure><p>In the realm of medical anomalies, few conditions captivate curiosity and concern quite like <a href="https://www.sciencedirect.com/science/article/pii/S2213219822004779?casa_token=8RR-HH-wRMsAAAAA:yQQyjdItTR5FfFnwEPBZSeXr-wfU51JO25uVByTSzsERiCwbUCQ1eyIXXbj4y0BYleWB5RBT7SA">aquagenic urticaria</a>, commonly known as “water allergy”. </p>
<p>This rare affliction transforms the seemingly innocuous act of water contact into a tormenting ordeal, afflicting people such as 22-year-old <a href="https://www.dailymail.co.uk/health/article-13155961/Woman-rare-water-allergy.html">Loren Montefusco</a> from South Carolina, US. </p>
<p>Diagnosed with water allergy, Montefusco’s life is marked by the excruciating sensation of a burning itch deep beneath her skin. This is triggered by the mere touch of water. Her account reveals the harrowing experiences faced by those grappling with this puzzling condition.</p>
<p>At its core, water allergy is believed to arise from an <a href="https://www.tandfonline.com/doi/full/10.2147/JAA.S91505">abnormal immune response</a> triggered by water’s interaction with the skin. Think of your immune system as a vigilant guardian, always on alert for invaders. In aquagenic urticaria, water somehow <a href="https://pubmed.ncbi.nlm.nih.gov/9647271/">triggers an alarm response</a>. This leads to the release of substances like histamine – causing hives, welts and itching.</p>
<p>Researchers have pinpointed mutations in <a href="https://www.tandfonline.com/doi/full/10.2147/JAA.S91505">specific genes</a> associated with water allergy, such as the FABP5 gene, crucial for skin barrier function. Mutations in this gene disrupt the skin’s ability to repel water, activating an inflammatory response.</p>
<p>Variations in <a href="https://www.sciencedirect.com/science/article/pii/S1027811717302069">genes involved</a> in immune regulation and skin integrity also contribute to susceptibility. However, environmental factors such as hormonal changes or chemical exposure can influence its severity.</p>
<p>Understanding the genetic basis offers insights into how the disease occurs and potential therapies. By identifying specific genetic markers, personalised treatment approaches targeting underlying mechanisms can be developed.</p>
<p>Despite these strides, much about water allergy remains unknown. However, by integrating insights from genetics, immunology and dermatology, scientists aim to unravel the secrets of this rare water allergy, offering hope for improved diagnosis and management.</p>
<p>The first documented mention of water allergy dates to the <a href="https://www.tandfonline.com/doi/full/10.2147/JAA.S91505">late 20th century</a>, with case reports detailing the perplexing experiences of people afflicted by water-induced hives. </p>
<p>Since then, sporadic cases have dotted medical literature, contributing to our <a href="https://www.sciencedirect.com/science/article/pii/S2213219823006943">evolving understanding</a> of this ailment. Recent trends suggest a gradual increase in cases, driven by heightened awareness among healthcare professionals and improved diagnostic capabilities.</p>
<p>Water allergy’s rarity adds to its mystique. Despite its obscurity, the condition leaves an indelible mark on those affected, shaping their experiences in profound and unexpected ways. Current estimates suggest that <a href="https://www.sciencedirect.com/science/article/pii/S2213219823006943">fewer than 100 cases</a> have been reported globally. This underscores its status as one of the rarest form of hives.</p>
<p>Managing this allergy presents a formidable challenge for patients and healthcare providers alike. Here are the strategies used.</p>
<h2>Treatments</h2>
<p>Conventional allergy treatments (<a href="https://www.sciencedirect.com/science/article/pii/S2213219822004779?casa_token=QpzXDlDctqcAAAAA:m2lS9f4xTQ_sTo6BL6xYUUOPi4ztydO_3M1NuzNuDXSPDQMjWxLPszYEoNd-eWULtBSOhJOHq4U">antihistamines, corticosteroids</a>) offer temporary relief but may not address the underlying cause.</p>
<p>Experimental therapies such as <a href="https://www.sciencedirect.com/science/article/pii/S019096229770344X?casa_token=Lc1UtgdCLeQAAAAA:J1FYpWef1WdNo-La-IMRXobUKbdN61V7ZNEDk-ytpTwjjQsrwtU1XAOAoTlulq-OtNmhrPOniR0">phototherapy</a> (exposing the skin to ultraviolet light) aim to calm the immune response and reduce inflammation. This therapy has shown some promise in alleviating symptoms.</p>
<p>Biologic agents, so-called “large-molecule drugs” made from proteins, target specific immune pathways implicated in allergic reactions. They offer a more <a href="https://www.hindawi.com/journals/ja/2013/130905/">targeted therapeutic approach</a> that holds potential for <a href="https://www.nature.com/articles/nri1589">long-term symptom management</a>.</p>
<p>Avoiding water is tricky and involves careful planning, including <a href="https://www.tandfonline.com/doi/full/10.2147/JAA.S91505">alternative ways to stay clean</a>.</p>
<p>Using <a href="https://www.sciencedirect.com/science/article/pii/S2213219822004779?casa_token=RCaQD7kOdKoAAAAA:4au1UvCrCXF6C5OKc8egMj_Wc_jPi_dO9xZ5eFqjg4fl0R9H9SUgCwNcBJCsttEeBRw__kjLGnc">protective barriers</a>, such as emollient creams, can help create a layer between the skin and water, which may help reduce symptom severity and frequency.</p>
<h2>Psychological support</h2>
<p><a href="https://allergyasthmanetwork.org/health-a-z/chronic-urticaria/aquagenic-urticaria/">Counselling and support groups</a> provide a safe space for people to navigate the emotional difficulties associated with living with a chronic and misunderstood condition like aquagenic urticaria.</p>
<p>Offering coping strategies and fostering resilience can empower patients to better cope with the uncertainties and stressors of their condition, improving overall quality of life.</p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S0190962218301427?casa_token=abCKSfbJVBAAAAAA:40TcfAWx6Gp4L1b6XCP1Pv8XUDaqMW5lht65nxBRgSx_PX-zC1rpPwQt55aRYDlChX8m1yRICkI">Further investigation</a> into immune system mechanisms underlying aquagenic urticaria is essential to finding new treatments.</p>
<p>Continued clinical trials and studies are crucial to evaluate the efficacy and safety of emerging therapies, such as phototherapy and biologic agents, in managing aquagenic urticaria. Unfortunately, these studies are limited by <a href="https://www.sciencedirect.com/science/article/abs/pii/S2213219823006943?fr=RR-2&ref=pdf_download&rr=86457bacdadfdcaf">patient numbers</a>.</p><img src="https://counter.theconversation.com/content/225107/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There is no cure for ‘aquagenic urticaria’, but some promising treatments are on the horizon.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2217202024-03-11T21:26:04Z2024-03-11T21:26:04ZAllergen warning: “Vegan” foods may contain milk and eggs<figure><img src="https://images.theconversation.com/files/570731/original/file-20240112-29-t9z77z.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C989%2C667&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When buying pre-packaged foods, consumers with allergies rely on the declarations in the list of ingredients to identify safe foods.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>The popularity of vegan diets continues to increase around the world. Indeed, in 2023, the vegan food market grew to <a href="https://www.expertmarketresearch.com/reports/vegan-food-market">more than US$27 billion</a>.</p>
<p>The term “vegan” usually refers to foods that contain no animal ingredients (meat, poultry, eggs, milk, fish, seafood).</p>
<p>While some consumers consider them to be healthier, vegan foods are also an interesting alternative for consumers concerned about the environment, sustainable development, and animal welfare.</p>
<p>But another type of consumer may be turning to these products for a completely different reason: people who are allergic to proteins of animal origin, such as cow’s milk and eggs.</p>
<p>In view of this, <a href="https://parera.ulaval.ca">our research group</a>, a leader in food allergen risk analysis in Canada, decided to explore <a href="https://link.springer.com/article/10.1186/s13223-023-00836-w">the following two questions</a>:</p>
<ul>
<li><p>Do consumers who are allergic to animal proteins consider vegan products to be safe?</p></li>
<li><p>And, if so, are these products truly safe for them?</p></li>
</ul>
<h2>What’s in it for consumers with allergies?</h2>
<p>The answers to these questions are crucial for people with food allergies who risk suffering potentially severe reactions (anaphylaxis) from consuming these products.</p>
<p>Food allergies affect around <a href="https://www.jaci-inpractice.org/article/S2213-2198(19)30912-2/fulltext">six per cent of Canadians</a>, including 0.8 per cent who are allergic to eggs, and 1.1 per cent to milk.</p>
<p>Despite the fact that different forms <a href="https://foodallergycanada.ca/living-with-allergies/allergy-treatments-and-therapies/treatments-and-therapies/">of immunotherapy or allergen desensitization</a> have shown promising results, the most effective strategy for avoiding allergic reactions is still to refrain from eating foods that may contain allergens.</p>
<p>When buying pre-packaged foods, consumers with allergies rely on declarations in the list of ingredients to identify foods that are safe for them. Regulatory authorities who are responsible for the quality and safety of food recognize the importance of accurate ingredients declarations for allergic consumers. Thus, it is <a href="https://www.canada.ca/en/health-canada/services/food-nutrition/food-labelling/allergen-labelling.html">mandatory</a> to list every allergen that has been voluntarily added to a pre-packaged food item.</p>
<p>However, when it comes to ingredients that may be unintentionally present — for example, as due to cross-contact during food processing — there is a regulatory gap. These ingredients are generally identified with the warning “may contain,” which is used (or sometimes <a href="https://www.sciencedirect.com/science/article/abs/pii/S2213219818300102">overused</a>) voluntarily and randomly by food processors.</p>
<p>Furthermore, the term “vegan” is neither standardized nor defined in Canadian regulations. In fact, <a href="https://inspection.canada.ca/food-labels/labelling/industry/composition-and-quality/eng/1625516122300/1625516122800?chap=2">the Canadian Food Inspection Agency</a> notes that, with regard to the use of the term “vegan,”</p>
<blockquote>
<p>…companies can apply additional criteria or standards that take account of other factors in addition to the ingredients of the food.</p>
</blockquote>
<p>However, details or examples of these elements are not provided. This lack of a precise regulatory definition prevents the implementation of compliance requirements.</p>
<p>Yet, most <a href="https://recalls-rappels.canada.ca/en/search/site?search_api_fulltext=vegan">recalls</a> of products marketed as “vegan” are due to the presence of undeclared ingredients of animal origin, in particular milk and eggs.</p>
<h2>What do consumers with food allergies say?</h2>
<p>In this context, and as part of a <a href="https://www.researchsquare.com/article/rs-2583779/v1">survey</a> of consumers with allergies conducted in collaboration with <a href="https://foodallergycanada.ca">Food Allergy Canada</a>, we asked participants who indicated that they were allergic (or were the parents of a child who was allergic) to eggs or milk if they bought products marketed as “vegan.”</p>
<p>Of the 337 respondents, 72 per cent said they sometimes included these products in their purchases, 14 per cent said they always did, and 14 per cent never.</p>
<p>These <a href="https://link.springer.com/article/10.1186/s13223-023-00836-w">results</a> suggest that these consumers do, indeed, consider the claim “vegan” as an indicator of the absence of animal proteins — an absence which, again, is not supported by any regulatory requirement or definition.</p>
<p>Since the absence of these ingredients is not guaranteed, these consumption habits could put people who are allergic to eggs and/or milk at risk.</p>
<p>An education campaign to clarify that the term “vegan” is an indicator of dietary <em>preferences</em> and not <em>risks</em> would therefore be important for this community.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/569134/original/file-20240112-29-5nq5bg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="dark chocolate" src="https://images.theconversation.com/files/569134/original/file-20240112-29-5nq5bg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569134/original/file-20240112-29-5nq5bg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=372&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569134/original/file-20240112-29-5nq5bg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=372&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569134/original/file-20240112-29-5nq5bg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=372&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569134/original/file-20240112-29-5nq5bg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=467&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569134/original/file-20240112-29-5nq5bg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=467&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569134/original/file-20240112-29-5nq5bg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=467&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some dark chocolate bars marketed as ‘certified vegan’ contain milk proteins.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Do vegan products contain ingredients of animal origin?</h2>
<p>The fact that 86 per cent of survey respondents buy “vegan” products suggests that the incidence of allergic reactions linked to these foods is potentially rare.</p>
<p>We therefore <a href="https://link.springer.com/article/10.1186/s13223-023-00836-w">analyzed</a> the egg and milk protein content of “vegan” and “plant-based” products marketed in Québec.</p>
<p>A total of 124 products were analyzed for the presence of egg (64) and/or milk (87) proteins.</p>
<p>Egg protein was not detected in any samples, but five samples contained milk proteins: these included four dark chocolate bars marketed as “certified vegan” and a supermarket brand chestnut cake.</p>
<p>These five products declared the potential presence of milk with a warning, “may contain milk.”</p>
<p>We used the concentrations of milk proteins quantified in these products, combined with the quantities of the food that would be consumed in a single eating occasion, to calculate an exposure dose, in milligrams of allergen protein. We then estimated the probability of these doses provoking a reaction in the allergic populations concerned by using <a href="https://www.sciencedirect.com/science/article/pii/S0278691520307213">correlation models</a>. Our results show that the calculated doses could trigger reactions in six per cent of milk-allergic consumers, for the chocolate bars, and one per cent, for the cake.</p>
<h2>How can consumers with food allergies protect themselves?</h2>
<p>Although this level of risk may be perceived as low, it is likely to vary without notice. And this will remain the case until regulatory requirements are put in place.</p>
<p>In fact, rather than attributing it to the presence of a “vegan” or “plant-based” claim, this level of risk most likely reflects <a href="https://www.cell.com/heliyon/pdf/S2405-8440(22)02590-7.pdf">good allergen management practices</a>, characteristic of the North American food manufacturing sector.</p>
<p>Thus, even if a statement “may contain milk” seems contradictory in a “vegan” or “plant-based” product, people allergic to milk should interpret it as an indication that this product may pose a risk to their health.</p><img src="https://counter.theconversation.com/content/221720/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Samuel Godefroy's research activities are funded by the Natural Sciences and Engineering Research Council of Canada, the Foreign Agriculture Service of the United States Department of Agriculture, R-Biopharm GmbH and R-Biopharm Canada Inc. He acts as an expert advisor to members of the food and beverage industry, international organizations (the Food and Agriculture Organization of the United Nations, the United Nations Industrial Development Organization and the World Bank), international food regulatory bodies such as the China National Centre for Food Safety Risk Assessment and consumer organizations such as Food Allergy Canada. Godefroy is Chairman of the Board of the Global Food Regulatory Science Society (GFoRSS).</span></em></p><p class="fine-print"><em><span>Jérémie Théolier et Silvia Dominguez ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'ont déclaré aucune autre affiliation que leur poste universitaire.</span></em></p>Vegan foods are considered by most consumers to have no ingredients of animal origin, but they may actually contain milk proteins.Silvia Dominguez, Professionnelle de recherche en sciences des aliments, Université LavalJérémie Théolier, Professionel de recherche en sciences des aliments, Université LavalSamuel Godefroy, Professeur titulaire - Sciences des aliments, Université LavalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2139262024-02-23T12:57:17Z2024-02-23T12:57:17ZGut microbiome: meet Lactobacillus acidophilus – the gut health superhero<figure><img src="https://images.theconversation.com/files/577544/original/file-20240223-24-46adyy.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5176%2C3445&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Eating yoghurt is one way of getting more _Lactobacillus acidophilus_ into your diet.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-woman-home-eating-yogurt-111275633">Josep Suria/ Shutterstock</a></span></figcaption></figure><p>Your gut is like a bustling city of trillions of microscopic inhabitants – including bacteria. While some of these bacterial inhabitants are villains, causing illness, infection and disease, others are good – supporting our health and keeping things running smoothly. </p>
<p>But one species of bacterium in our gut is so good and does so much for our health, that it might well be compared to a gut superhero. This microbe goes by the name of <em><a href="https://www.cabdirect.org/cabdirect/abstract/19352701869">Lactobacillus acidophilus</a></em>. </p>
<p><em>Lactobacillus acidophilus</em> might sound like a mouthful, but don’t let its long name intimidate you. In simple terms, it’s a tiny bacterium that belongs to a group of microorganisms known for their <a href="https://pubmed.ncbi.nlm.nih.gov/24912386/">probiotic properties</a> – meaning it provides health benefits when consumed in adequate quantities.</p>
<p>This microbe hangs out in your gut (mainly your small intestine) and helps keep things running smoothly. In fact, <em>Lactobacillus acidophilus</em> has an incredible number of important functions.</p>
<p>It acts as a digestion buddy, munching on things you can’t digest entirely – such as certain sugars and fibres. For example, it helps digest foods rich in lactose (such as dairy products like milk, yogurt and cheese), as well as fermentable carbohydrates found in vegetables, fruits and grains. By doing so, <a href="https://pubmed.ncbi.nlm.nih.gov/30468509/">it helps break down your food</a>, making it easier for your body to absorb nutrients.</p>
<p>Since your gut is a delicate ecosystem, <em>Lactobacillus acidophilus</em> plays a crucial role in maintaining the right balance of bacteria by <a href="https://pubmed.ncbi.nlm.nih.gov/22254077/">preventing harmful bacteria</a> from taking over and causing trouble.</p>
<p>This microbe also <a href="https://pubmed.ncbi.nlm.nih.gov/23372900/">strengthens your body’s defence system</a>. It does this by helping your immune cells <a href="https://pubmed.ncbi.nlm.nih.gov/20823239/">communicate better</a> and stay alert so they’re ready to fight off invaders. </p>
<p>And when your stomach is upset or you’re stressed, <em>Lactobacillus acidophilus</em> is the microbe that comes to the rescue, soothing irritation and <a href="https://pubmed.ncbi.nlm.nih.gov/16728323/">helping ease digestive discomfort</a>.</p>
<figure class="align-center ">
<img alt="A man holds his stomach in pain." src="https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577545/original/file-20240223-20-cu5btb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of the benefits this microbe has is easing digestive problems.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-suffering-stomach-ache-sitting-on-488527312">Antonio Guillem/ Shutterstock</a></span>
</figcaption>
</figure>
<p>All of these important functions mean <em>Lactobacillus acidophilus</em> is a true friend to your body, and its affects on your health are pretty impressive, with benefits such as:</p>
<ul>
<li><strong>Happy tummies:</strong> By maintaining a balanced gut environment, your stomach will feel <a href="https://pubmed.ncbi.nlm.nih.gov/18274900/">more comfortable</a>, and you have less chance of experiencing tummy troubles such as <a href="https://pubmed.ncbi.nlm.nih.gov/16728323/">diarrhoea</a>, constipation and bloating.</li>
<li><strong>Immune support:</strong> By keeping your gut in tip-top shape, <em>Lactobacillus acidophilus</em> <a href="https://pubmed.ncbi.nlm.nih.gov/19651563/">helps protect you</a> from infections and illnesses. It’s shown to be particularly good at keeping <a href="https://pubmed.ncbi.nlm.nih.gov/23594927/">influenza</a> at bay. </li>
<li><strong>Controlling allergies and inflammation:</strong> Some studies suggest that having a strong colony of <em>Lactobacillus acidophilus</em> in your gut might <a href="https://pubmed.ncbi.nlm.nih.gov/19840300/">reduce the risk of allergies</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/24954372/">inflammation-related conditions</a> (such as eczema). It acts like a natural shield against <a href="https://pubmed.ncbi.nlm.nih.gov/26044853/">sneezing fits and sore joints</a>.</li>
<li><strong>Preserving mental wellbeing:</strong> Believe it or not, your gut health can influence your mood. <em>Lactobacillus acidophilus</em> might play a role in <a href="https://pubmed.ncbi.nlm.nih.gov/29521671/">promoting good mental wellbeing</a>.</li>
</ul>
<p>Given all the important roles that <em>Lactobacillus acidophilus</em> plays in your health, if you’re keen to fill your gut with this microbe you can find it in tasty fermented foods such as <a href="https://www.tandfonline.com/doi/abs/10.1080/10408398.2011.621169?casa_token=q5rNmHVBFjAAAAAA:79FQSbhMoQYMVxrw_WvyFaeHmSR50olvQO8JaGY9ZzluOnYAy_CLWaJhx6J8utAb1F6xgl60gYRN8w">yogurt and kefir</a>. </p>
<h2>A deeper look</h2>
<p>Even though we know a lot about <em>Lactobacillus acidophilus</em>, there’s still much to explore. Scientists are currently digging deeper to understand whether there are <a href="https://pubmed.ncbi.nlm.nih.gov/16875422/">different strains of this microbe</a> – and if each of these strains have unique abilities. </p>
<p>Scientists are also working on tailoring probiotics to a person’s specific needs. Imagine having a <a href="https://www.nature.com/articles/s41564-020-0721-1">personalised probiotic</a> superhero designed just for you. People with inflammatory bowel disease, weakened immune systems, allergies and mental health concerns may benefit from personalised products containing probiotic strains such as <em>Lactobacillus acidophilus</em>, because of the benefits it may have for these issues. </p>
<p>And finally, researchers are continuing to investigate the link between gut health and the brain – with scientists taking a particular interest in investigating how specifically <em>Lactobacillus acidophilus</em> might influence <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6445894/">mood and mental wellbeing</a>.</p>
<p><em>Lactobacillus acidophilus</em> is a tiny but mighty superhero in your gut, working hard to keep you healthy and happy. So the next time you enjoy <a href="https://www.tandfonline.com/doi/abs/10.1080/10408398.2011.621169?casa_token=q5rNmHVBFjAAAAAA:79FQSbhMoQYMVxrw_WvyFaeHmSR50olvQO8JaGY9ZzluOnYAy_CLWaJhx6J8utAb1F6xgl60gYRN8w">a yogurt or sip on some kefir</a>, think of it as giving your friendly gut superhero a high-five. </p>
<hr>
<p><em>This article is part of <a href="https://theconversation.com/uk/topics/meet-your-gut-microbes-150943?utm_source=InArticleTop&utm_medium=TCUK&utm_campaign=Health2024">Meet Your Gut Microbes</a>, a series about the rich constellation of bacteria, viruses, archaea and fungi that live in people’s digestive tracts. Scientists are increasingly realising their importance in shaping our health – both physical and mental. Each week we will look at a different microbe and bring you the most up-to-date research on them.</em></p>
<hr><img src="https://counter.theconversation.com/content/213926/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Fermented foods, such as yoghurt and kefir, are great sources of this immune-boosting microbe.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2221792024-02-21T13:13:29Z2024-02-21T13:13:29ZAntibiotic use on Kenya’s dairy farms is putting consumers and animals at risk<p>Farmers often use antibiotics to keep their livestock healthy. They’re sometimes used as “quick fixes”, to avoid more costly management measures like regular disinfection, waste management, routine vaccination or provision of clean drinking water. </p>
<p>Animal husbandry now accounts for about <a href="https://doi.org/10.1073/pnas.1503141112">two thirds</a> of the global consumption of antibiotics. As livestock and fish production grows, by 2030 the consumption of antibiotics is <a href="https://doi.org/10.1073/pnas.1503141112">projected to increase</a> by 67%.</p>
<p>Worryingly, this overuse in food animal production can create problems for both animals and people.</p>
<p>It can contribute to the development of antibiotic-resistant bacteria which, through food or environmental exposure such as drinking contaminated water, can be transmitted to people. </p>
<p>This means that some antibiotics may become ineffective in treating human infections. Antibiotic resistant infections are associated with <a href="https://doi.org/10.1016/S0140-6736(21)02724-0">4.95 million deaths</a> globally every year. Sub-Saharan Africa <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)02724-0/fulltext">accounts for</a> 22% of these.</p>
<p>Similarly, animals can also become infected with antibiotic-resistant bacteria. This leads to infections that are difficult or impossible to treat.</p>
<p>Our latest <a href="https://www.nature.com/articles/s41598-023-50325-8">study</a>, which focused on the central Kenyan highlands, looked at antibiotic use on smallholder dairy farms as well as antibiotic quality (substandard or counterfeit antibiotics). </p>
<p>Kenya is <a href="https://theconversation.com/kenyas-dairy-sector-is-failing-to-meet-domestic-demand-how-it-can-raise-its-game-176017">one of the largest</a> milk producers in Africa and one of the countries with the largest per capita consumption of milk. About <a href="https://afs.ca.uky.edu/dairy/extension/around-the-world">80%</a> of the milk produced in Kenya comes from smallholder farmers. </p>
<p>We found that smallholder farmers weren’t using antibiotics properly and were buying poor quality products. Also, traces of some antibiotics were found in milk.</p>
<p>This puts the health of both people and animals at risk.</p>
<h2>Antibiotic access and use</h2>
<p>For our study, we collected data from 248 dairy farms and 72 veterinary drug stores between February 2020 and October 2021. This included milk samples and the antibiotics themselves.</p>
<p>Most dairy farms surveyed reported using antibiotics at least once in the past year. This is not unusual – cows get sick. Dairy cows are especially prone to getting udder infections. </p>
<p>Antibiotics were used to treat and to prevent infections. Most were obtained through animal health service providers. A small number (6%) were bought directly from veterinary drug stores or other farmers. </p>
<p>Antibiotics were often sold without a prescription, and based on farmers’ own diagnosis. These are imprudent practices – the wrong antibiotic could be used to treat an infection or antibiotics could be overused. </p>
<p>The improper or excessive use of antibiotics in dairy farming can lead to the development of antibiotic-resistant bacteria. This then leads to economic losses for farmers, because animals will be less productive and the cost of treatment will grow. </p>
<p>It’s estimated that, as a result of antimicrobial resistance, livestock output could <a href="https://documents1.worldbank.org/curated/en/323311493396993758/pdf/final-report.pdf#page=17">fall by 11% by 2050</a>, with the highest decline in low income countries.</p>
<p>There’s also <a href="https://www.liebertpub.com/doi/full/10.1089/fpd.2017.2411">the risk</a> of these antibiotic-resistant bacteria being transmitted to humans, either directly through contact with animals or indirectly through the consumption of milk and dairy products. This can lead to infections that are difficult to treat, posing a public health risk. </p>
<h2>Antibiotics found in milk</h2>
<p>Also worrying, in this study we detected nine antibiotics in milk. Three samples exceeded <a href="https://www.fao.org/fao-who-codexalimentarius/sh-proxy/en/?lnk=1&url=https%253A%252F%252Fworkspace.fao.org%252Fsites%252Fcodex%252FStandards%252FCXM%2B2%252FMRL2e.pdf">global standards</a>. Antibiotics can get into milk supplies when withdrawal times are not strictly followed.</p>
<p>The presence of antibiotic residues in milk – even at low levels – can pose health risks to consumers, particularly those who are allergic to specific antibiotics. </p>
<p>Even for those who aren’t allergic, prolonged exposure to low levels of antibiotics <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7255607/">may contribute</a> to the development of antibiotic-resistant bacteria.</p>
<h2>Quality of antibiotics</h2>
<p>The study also examined the quality of antibiotics available in veterinary drug stores in central Kenya. </p>
<p>Poor quality, substandard, or counterfeit antibiotics can lead to ineffective treatment and prolonged illness. Low-quality antibiotics are even more likely to contribute to the development of antibiotic-resistant bacteria. This is because they won’t fully eradicate the pathogen (disease-causing bacteria), allowing them to adapt and become resistant. </p>
<p>Almost 44% of the antibiotics we tested were of poor quality. This has considerable implications for the efficacy and safety of these drugs. It can also contribute to antibiotic resistance.</p>
<h2>Implications</h2>
<p>The findings of the study underscore the need for better management practices on Kenya’s dairy farms. This includes:</p>
<ul>
<li><p>stricter regulation of antibiotic sales </p></li>
<li><p>improved veterinary oversight </p></li>
<li><p>education of farmers about the risks of antibiotic misuse. </p></li>
</ul>
<p>For a country like Kenya, where agriculture plays a significant role in the economy, ensuring livestock is healthy and productive is crucial for both farmers and the country. </p>
<p>We recommend a few steps for policymakers to take:</p>
<ul>
<li><p>strengthen regulations around antibiotic use in livestock</p></li>
<li><p>enhance surveillance and monitoring systems for antibiotic residues in milk</p></li>
<li><p>improve the quality control of antibiotics sold in veterinary drug stores</p></li>
<li><p>educate farmers about the responsible use of antibiotics</p></li>
<li><p>promote better animal husbandry practices that reduce the reliance on antibiotics.</p></li>
</ul><img src="https://counter.theconversation.com/content/222179/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dishon Muloi receives funding CGIAR Trust Fund, the Fleming Fund, the German Federal Ministry of Economic Cooperation and Development, and the Danish International Development Agency.</span></em></p><p class="fine-print"><em><span>Arshnee Moodley receives funding from the CGIAR Trust Fund, the Fleming Fund, the German Federal Ministry of Economic Cooperation and Development, Danish International Development Agency, and International Centre for Antimicrobial Resistance Solutions.</span></em></p>Kenya’s smallholder farmers aren’t using antibiotics properly, some are of poor quality and some antibiotics are being found in milk.Dishon Muloi, Research scientist, International Livestock Research Institute Arshnee Moodley, AMR Team Leader, CGIAR System OrganizationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2184072023-12-05T12:39:03Z2023-12-05T12:39:03ZChristmas tree syndrome: why the festive evergreen can make your nose run – and what you can do about it<figure><img src="https://images.theconversation.com/files/563330/original/file-20231204-29-cia24o.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C5760%2C3819&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">These health issues are trigged by the allergens that normally reside in live Christmas trees.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ruined-christmas-holidays-young-handsome-man-2221562955">voronaman/ Shutterstock</a></span></figcaption></figure><p>Decorating the Christmas tree is a beloved tradition for many of us during the festive season. While some people prefer using and reusing an artificial tree as an environmentally friendly way to enjoy the holiday spirit, others hunt instead for the perfect real tree to adorn with ornaments and cluster presents around.</p>
<p>But some people who decide to get a real tree may find that after it has been decorated they begin to experience cold-like symptoms. While many may simply chalk these symptoms up to having caught a cold – or even COVID – the culprit may actually be a little-known condition called <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1930673/">Christmas tree syndrome</a>. </p>
<p>Christmas tree syndrome encompasses a spectrum of health issues triggered by exposure to the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1930673/">allergens residing on live Christmas trees</a>. For those who are sensitive to allergens, prolonged exposure to live Christmas trees can lead to <a href="https://www.sciencedirect.com/science/article/abs/pii/B9780128045435000075">respiratory</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1930903/">skin health issues</a>.</p>
<p>The <a href="https://www.thermofisher.com/allergy/gb/en/living-with-allergies/understanding-allergies/is-christmas-tree-allergy-making-you-sick.html">main symptoms</a> of Christmas tree syndrome include a stuffy or runny nose, sneezing, irritated eyes, coughing, wheezing and itchy throat. Asthma symptoms may also worsen. <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.0105-1873.2005.00495.x">Skin-related symptoms</a> may include redness, swelling, and itching.</p>
<p>This phenomenon happens thanks to the ecology of live trees, which carry microscopic entities – including <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1930673/">pollen and fungi</a>. Pollen, a notorious outdoor allergen, may hitch a ride into our homes, while fungi find a cosy haven in cold, damp Christmas tree farms and garden centres.</p>
<p>Live Christmas trees can also carry mould. Notably, a single Christmas tree can host more than <a href="https://www.annallergy.org/article/S1081-1206(11)00160-8/fulltext">50 species of mould</a>, creating a habitat for these tiny yet potentially troublesome organisms. Many of the mould varieties found on trees are those <a href="https://www.annallergy.org/article/S1081-1206(11)00160-8/fulltext">most likely to trigger allergies</a>, including <em>Aspergillus</em>, <em>Penicillium</em>, and <em>Cladosporium</em>.</p>
<p>Researchers have also <a href="https://www.annallergy.org/article/S1081-1206(11)00160-8/fulltext#back-bib3">closely measured mould counts</a> in rooms containing live Christmas trees. During the first three days the tree is indoors, mould spore counts measure about 800 spores per cubic meter of air. On the fourth day, however, spore counts begin rising – eventually reaching 5,000 spores per cubic meter within two weeks.</p>
<p>Mould grows best in <a href="https://health.uconn.edu/occupational-environmental/wp-content/uploads/sites/25/2015/12/mold_guide.pdf">warm, wet and humid conditions</a>. So when the tree is brought indoors, the warmer climate <a href="https://medcraveonline.com/MOJI/MOJI-02-00045.pdf">significantly increases</a> mould production. </p>
<p>Pine pollen is not a major issue for allergy-sufferers when it comes to Christmas trees. But Christmas trees can come into contact with <a href="https://www.sciencedirect.com/science/article/abs/pii/S0021870730901050">other known allergens</a> while they’re growing, which can then be carried into the house. For example, grass pollen can stick to the sap in a Christmas tree during the spring. Then, when the tree is harvested and brought indoors, the sap dries out, and the trapped pollen particles are released into the air.</p>
<h2>Managing symptoms</h2>
<p>Certain people are at higher risk of experiencing Christmas tree syndrome. People with asthma or chronic obstructive pulmonary syndrome (COPD) may be more sensitive to allergens – and these allergens may also exacerbate symptoms such as coughing and wheezing.</p>
<p>People who suffer from allergies are also at greater risk – with research showing <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1930673/">7% of allergy-sufferers</a> experienced a spike in symptoms when they had a Christmas tree in their home. People with skin issues (such as contact dermatitis and itching) may also find that their symptoms worsen around fresh Christmas trees.</p>
<p>Timely recognition of symptoms is crucial to mitigate the impact of Christmas tree syndrome. So if you do suffer from allergies, here’s what you can do:</p>
<ol>
<li><p><strong>Select your tree carefully:</strong> Opt for varieties with lower allergenic potential. Fir trees, such as Douglas and Fraser, are known for producing fewer allergens compared to <a href="https://www.cabdirect.org/cabdirect/abstract/19700607118">spruce or pine</a>. </p></li>
<li><p><strong>Inspect your tree:</strong> Conduct a <a href="https://www.annallergy.org/article/S1081-1206(10)60670-9/fulltext">meticulous inspection for signs of fungi</a> before bringing the tree indoors. Focus on areas where moisture may accumulate, as damp conditions foster mould growth. The most common mould found on Christmas trees is <em>Aspergillus</em>, which will look black on the surface and usually white-ish or yellow underneath.</p></li>
<li><p><strong>Proper maintenence:</strong> <a href="https://www.entandallergyspecialists.com/uncategorized/can-christmas-trees-cause-allergy-symptoms/">Regularly water live trees</a> to prevent dehydration, as this can lead to mould growth. A well-hydrated tree is also less likely to harbour fungus. And since warm, moist environments increase mould growth, try to keep your house ventilated while it’s up. You might even consider using a dehumidifier to decrease moisture levels in your home.</p></li>
<li><p><strong>Minimise direct contact:</strong> Try to avoid too much direct contact when decorating the tree. Wearing gloves might be one may of reducing the risk of skin-related reactions.</p></li>
<li><p><strong>Go artificial:</strong> Consider artificial trees as a <a href="https://jamanetwork.com/journals/jama/article-abstract/662569">practical alternative</a>. These eliminate the risk of allergens and can be reused – reducing their environmental impact. </p></li>
</ol>
<p>Christmas tree syndrome can be a nuisance. But by considering the science and taking precautions, you can ensure an enjoyable and allergen-free festive season.</p><img src="https://counter.theconversation.com/content/218407/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>People who usually suffer from allergies are most at risk.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2128742023-11-08T19:10:33Z2023-11-08T19:10:33ZDo you think you have a penicillin allergy? You might be wrong<figure><img src="https://images.theconversation.com/files/555945/original/file-20231025-19-tbp1oy.jpg?ixlib=rb-1.1.0&rect=98%2C160%2C8144%2C5326&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/these-all-possible-causes-shot-young-2148946861">Shutterstock</a></span></figcaption></figure><p><em>Antimicrobial resistance is <a href="https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance">one of the biggest global threats</a> to health, food security and development. This month, The Conversation’s <a href="https://theconversation.com/au/topics/the-dangers-of-antibiotic-resistance-146983">experts explore how we got here and the potential solutions</a>.</em></p>
<hr>
<p>Penicillins are the most prescribed class of antibiotics in Australia. Originally derived from a fungus, penicillin antibiotics such as amoxicillin are used to treat common infections, including chest, sinus, ear, urinary tract and skin infections. </p>
<p>Penicillins are effective against a wide range of bacteria that cause common infections. But their activity is not so broad as to impact on good bacteria in our gut like other antibiotic classes do. They’re also cheap and readily accessible.</p>
<p>Up to <a href="https://www.sciencedirect.com/science/article/pii/S2772829322000376#bib1">20%</a> of Australians admitted in hospital say they have a penicillin allergy.</p>
<p>But not everyone who thinks they’re allergic to penicillin actually is. Research from <a href="https://www.sciencedirect.com/science/article/pii/S2772829322000376?via%3Dihub">our team</a> and others suggests that if we assess all these patients, up to 90% are not allergic to it.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/weekly-dose-penicillin-the-mould-that-saves-millions-of-lives-63770">Weekly Dose: penicillin, the mould that saves millions of lives</a>
</strong>
</em>
</p>
<hr>
<h2>Why does it matter?</h2>
<p>People who mistakenly think they’re allergic to penicillin may not get the most effective or safest antibiotics to treat their infection. </p>
<p>They are also at greater risk of developing <a href="https://www.sciencedirect.com/science/article/abs/pii/S009167491301467X">multidrug-resistant infections</a> or “superbugs”. This is because the antibiotic will kill off the bacteria that are susceptible to it, but the resistant bacteria are left behind to proliferate and cause further infection.</p>
<p>People who receive second-line antibiotics are more likely to have complications, such as <a href="https://www.sciencedirect.com/science/article/abs/pii/S009167491301467X">antibiotic-induced gut infections</a>. Second-line antibiotics tend to have a wider range of activity, killing both the bacteria causing infection, and the good bacteria required to keep our gut in balance. This allows bugs like <em>Clostridium difficile</em>, which normally lives in our gut but is controlled by other bacteria, to overgrow and cause inflammation. </p>
<p>For the health system, using second-line antibiotics means longer, more complicated hospital stays. Hospital stays for patients with penicillin allergies cost up to <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2222.2003.01638.x">63% more</a> more than those without. It also results in greater costs for medications and greater resources required to treat the patient. </p>
<h2>Why do people think they’re allergic?</h2>
<p>People incorrectly believe they are allergic to penicillin for a number of reasons. </p>
<p>They may have experienced side effects from penicillin, such as nausea or diarrhoea. But though unpleasant, this doesn’t mean an allergy.</p>
<p>Others had a rash as a child, but this could have been due to the illness itself or an interaction between the virus and the antibiotic. An Epstein-Barr viral infection treated with amoxicillin, for example, <a href="https://pubmed.ncbi.nlm.nih.gov/23589810/">causes</a> a fine, red rash. </p>
<figure class="align-center ">
<img alt="Woman sits it wheelchair in hospital" src="https://images.theconversation.com/files/555944/original/file-20231025-23-83c11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/555944/original/file-20231025-23-83c11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/555944/original/file-20231025-23-83c11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/555944/original/file-20231025-23-83c11.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/555944/original/file-20231025-23-83c11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/555944/original/file-20231025-23-83c11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/555944/original/file-20231025-23-83c11.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It’s important to know your true allergy status when you go to hospital.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/rear-view-senior-asian-woman-sitting-1605865573">Shutterstock</a></span>
</figcaption>
</figure>
<p>Some believe a family history of reactions to penicillin means they cannot take them. But there is no evidence penicillin allergy is inherited. </p>
<p>If some time has passed between exposure, people can lose the allergic response. This is typically seen in adults who had a mild allergy as a child, but lose the response with time, so are said to have “grown out” of their allergy.</p>
<p>Then there are people who have had a genuine and serious reaction to penicillin. This includes anaphylaxis, with profound swelling, breathing difficulties and low blood pressure, and severe life-threatening reactions such as <a href="https://www.ncbi.nlm.nih.gov/books/NBK459323/#:%7E:text=Stevens%2DJohnson%20syndrome%2Ftoxic%20epidermal,in%20over%2080%25%20of%20cases.">Steven-Johnson’s syndrome</a>, which causes widespread blisters and wounds that resemble burns.</p>
<h2>Testing for penicillin</h2>
<p>When someone says they have a penicillin allergy, we first get them to explain what happened with the reaction, including to what antibiotic, in what context and how severe it was. </p>
<p>Then we perform skin tests to further assess the person’s risk of reaction. If skin tests are negative, we can then give the patient the penicillin in question under supervision (a “challenge”) to see if they react. </p>
<figure class="align-center ">
<img alt="Allergist performs skin test on patient's arm" src="https://images.theconversation.com/files/555946/original/file-20231025-27-q72zcu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/555946/original/file-20231025-27-q72zcu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/555946/original/file-20231025-27-q72zcu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/555946/original/file-20231025-27-q72zcu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/555946/original/file-20231025-27-q72zcu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/555946/original/file-20231025-27-q72zcu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/555946/original/file-20231025-27-q72zcu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Skin tests assess a patient’s reaction to the allergen.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/allergy-skin-prick-tests-184605983">Shutterstock</a></span>
</figcaption>
</figure>
<p>Some people can skip the skin tests altogether and go straight to the challenge if the history tells us they are at low risk of reacting.</p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S2772829322000376?via%3Dihub">Our study</a> followed 195 patients who reported a penicillin allergy across six Sydney hospitals. In the first phase, we assessed 85 people and found 82% weren’t allergic to penicillin. </p>
<p>In the second phase, we assessed 110 people, of whom 69% weren’t allergic.
This is slightly lower than research on the population as a whole, because we only looked at people who were referred for an allergy assessment. Many more patients carry an allergy label than those referred for testing.</p>
<p>In our study, eight weeks after their test, just 54% of participants in phase one correctly knew their penicillin allergy status. Some allergic people believed they were not allergic, and many non-allergic people believed they were allergic.</p>
<p>For phase two, we ensured people received a standardised letter outlining their results in addition to having a doctor or nurse explain them. This time, 92% were correct in their understanding when contacted eight weeks later. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/will-we-still-have-antibiotics-in-50-years-we-asked-7-global-experts-214950">Will we still have antibiotics in 50 years? We asked 7 global experts</a>
</strong>
</em>
</p>
<hr>
<h2>Reducing long waits for allergy tests</h2>
<p>Ruling out allergies among people who think they can’t have penicillin is time- and labour-intensive. The wait time from someone first being referred to an allergy clinic to having testing can be <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10026071/">up to two years</a>. And it’s usually not available outside major metropolitan hospitals. </p>
<p>We need to improve access to testing and also look at <em>when</em> people can access allergy services. When a person is sick in hospital with a serious infection, it’s not the right time for testing.</p>
<p>We also need to ensure the results of allergy tests translate to the real world so people know their true allergy status. The fragmentation of our medical records are a barrier to clear and effective communication of a patient’s true allergy status, and urgently need to be improved.</p>
<hr>
<p><em>Read the other articles in The Conversation’s series on the dangers of antibiotic resistance <a href="https://theconversation.com/au/topics/the-dangers-of-antibiotic-resistance-146983">here</a>.</em></p><img src="https://counter.theconversation.com/content/212874/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Winnie Tong has received funding from Maridulu Budyari Gumal, the Sydney Partnership for Health, Education, Research and Enterprise (SPHERE), Triple I Clinical Academic Group seed grant 2017, and the Balnaves Foundation. The authors would like to acknowledge Professor Andrew Carr, their collaborators and participants on this project. </span></em></p><p class="fine-print"><em><span>Jacqueline Loprete does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Up to 20% of Australians admitted in hospital say they have a penicillin allergy. But not everyone who thinks they’re allergic to penicillin actually is.Winnie Tong, Clinical Immunologist & Allergist, Immunopathologist and Senior Lecturer, UNSW SydneyJacqueline Loprete, Postdoctoral fellow, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2130712023-09-20T05:57:51Z2023-09-20T05:57:51ZHow do hay fever treatments actually work? And what’s best for my symptoms?<figure><img src="https://images.theconversation.com/files/549215/original/file-20230920-21-6mbsm0.jpg?ixlib=rb-1.1.0&rect=9%2C224%2C6221%2C3895&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ill-upset-african-woman-blowing-running-1444224848">Shutterstock</a></span></figcaption></figure><p>Spring has sprung and many people are welcoming longer days and more time outdoors. But for <a href="https://www.aihw.gov.au/reports/chronic-respiratory-conditions/allergic-rhinitis-hay-fever/contents/allergic-rhinitis">almost one in five Australians</a>, spring also brings the misery of watery, itchy red eyes, a runny, congested nose, and sneezing. </p>
<p>Hay fever (also known as allergic rhinitis) is caused when an allergen enters the nose or eyes. Allergens are harmless airborne substances the body has incorrectly identified as harmful. This triggers an immune response, which leads to the release of inflammatory chemicals (mediators) – one of which is histamine.</p>
<p>Allergens that trigger hay fever differ from person to person. Common seasonal allergens include tree, grass and weed pollens (year-round allergens include dust mites, mould and pet dander). It’s now <a href="https://www.sciencedirect.com/science/article/pii/S132602002302191X">pollen season</a> in many parts of Australia, with pollen counts at their highest and hay fever cases surging. </p>
<p>So what medicines can prevent or reduce hay fever symptoms, and how do they work?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/do-i-have-covid-or-hay-fever-heres-how-to-tell-188030">Do I have COVID or hay fever? Here’s how to tell</a>
</strong>
</em>
</p>
<hr>
<h2>Antihistamines</h2>
<p>Knowing the release of histamine is a cause of hay fever symptoms, it’s unsurprising that <em>anti</em>-histamines are one of the most frequently recommended medicines to treat hay fever. </p>
<p>Antihistamines block histamine from binding to histamine receptors in the body and having an effect, reducing symptoms.</p>
<p>In Australia, we broadly have two types. The older sedating (introduced in the <a href="https://www.tga.gov.au/news/safety-alerts/first-generation-antihistamines-winter-warning">1940s</a>) and newer, less-sedating (introduced in the 1980s) antihistamines. </p>
<p>Less-sedating antihistamines used to treat allergic rhinitis include bilastine (Allertine), cetirizine (Zyrtec), loratadine (Claratyne) and fexofenadine (Telfast). Bilastine, which came onto the Australian market only last year, is only available from a pharmacy, on recommendation from a pharmacist. The others have been around longer and are available at supermarkets and in larger quantities from pharmacies. Cetirizine is the <a href="https://www.tga.gov.au/resources/publication/scheduling-decisions-interim/scheduling-delegates-interim-decisions-and-invitation-further-comment-accsacms-november-2016/35-cetirizine-hydrochloride#:%7E:text=Risks%20of%20cetirizine%20hydrochloride%20use,significant%20at%20the%20proposed%20doses.">most likely</a> (of the less-sedating antihistamines) to cause sedation.</p>
<p>The older sedating antihistamines (such as promethazine) cross the blood-brain barrier, causing drowsiness and even brain fog the next day. They have lots of side effects and potential drug interactions, and as such have little place in the management of hay fever. </p>
<p>The newer less-sedating antihistamines are <a href="https://australianprescriber.tg.org.au/articles/antihistamines-and-allergy.html#:%7E:text=Less%20sedating%20antihistamines%20are%20equally,an%20ongoing%20good%20safety%20profile">equally effective</a> as the older sedating ones.</p>
<figure class="align-center ">
<img alt="Woman with red eyes touches her face" src="https://images.theconversation.com/files/549218/original/file-20230920-29-y20eo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/549218/original/file-20230920-29-y20eo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/549218/original/file-20230920-29-y20eo4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/549218/original/file-20230920-29-y20eo4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/549218/original/file-20230920-29-y20eo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/549218/original/file-20230920-29-y20eo4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/549218/original/file-20230920-29-y20eo4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Hay fever can cause watery, itchy red eyes.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/closeup-on-young-woman-inflamed-eyes-2271555335">Shutterstock</a></span>
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<p>Antihistamines are usually taken orally (as a tablet or solution) but there are also topical preparations such as nasal sprays (azelastine) and eye drops. Antihistamine nasal sprays have <a href="https://www.sciencedirect.com/science/article/abs/pii/S108112061000743X">equal to or better efficacy</a> than oral antihistamines.</p>
<p>The individual response to antihistamines varies widely. For this reason, you may need to trial several different types of antihistamines to see which one works best for you.</p>
<p>Increasing the dose of an antihistamine, or combining an oral and topical antihistamine, does not provide any additional benefit. Paying extra for a brand name doesn’t offer any more or less effect than the generic (both have the same active ingredient and are <a href="https://www.tga.gov.au/news/news/generic-prescription-medicines-fact-sheet">bioequivalent</a>, which means they have the same outcomes for patients).</p>
<h2>Steroid nasal sprays</h2>
<p>If your symptoms don’t improve from antihistamines alone, a nasal spray containing a corticosteroid is often recommended. </p>
<p>Corticosteroids prevent the release of several key chemicals that cause inflammation. How they work is complex: in part, corticosteroids “turn off” the production of late phase inflammatory mediators (cytokines and chemokines). This reduces the future release of more inflammatory mediators, which reduces inflammation.</p>
<p>Corticosteroids and antihistamines have different mechanisms of action. Research shows corticosteroid nasal sprays are <a href="https://journals.sagepub.com/doi/full/10.2500/ajra.2016.30.4397">more effective</a> than antihistamines in controlling an itchy, runny, congested nose. But when instilled into the nose, corticosteroids <a href="https://aao-hnsfjournals.onlinelibrary.wiley.com/doi/10.1016/j.otohns.2007.10.027">also reduce</a> the eye symptoms of hay fever. </p>
<p>There are also nasal sprays that contain both an antihistamine and corticosteroid. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/sneezing-with-hay-fever-native-plants-arent-usually-the-culprit-190336">Sneezing with hay fever? Native plants aren't usually the culprit</a>
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<p>While there are a range of corticosteroid nasal sprays containing different active ingredients, a large study published this year shows they are all <a href="https://www.frontiersin.org/articles/10.3389/fphar.2023.1184552/full">about as effective as each other</a>, and work best when they have been taken for several days. </p>
<h2>Sodium cromoglycate</h2>
<p>Another medicine used to treat hay fever symptoms is sodium cromoglycate, which is available as an eye drop and over-the-counter in pharmacies. </p>
<p>This medicine is known as a mast cell stabiliser. As the name suggests, it stabilises or prevents mast cells from breaking down. When mast cells break down, they release histamine and other chemicals that cause inflammation. </p>
<p>This eye drop is both a preventative and treatment medicine, usually used before allergies strike. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9375451/">Evidence shows</a> it is effective at reducing the symptoms of allergic conjunctivitis (eye inflammation from allergies). </p>
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<img alt="Man blows nose at pharmacy check out" src="https://images.theconversation.com/files/549220/original/file-20230920-15-ow0w0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/549220/original/file-20230920-15-ow0w0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/549220/original/file-20230920-15-ow0w0v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/549220/original/file-20230920-15-ow0w0v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/549220/original/file-20230920-15-ow0w0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/549220/original/file-20230920-15-ow0w0v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/549220/original/file-20230920-15-ow0w0v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">If you’re not sure where to start, your pharmacist or prescriber can talk you through your options.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-pharmacist-suggesting-medical-drug-buyer-102268021">Shutterstock</a></span>
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<h2>Decongestants</h2>
<p>Decongestants constrict blood vessels. They can be taken orally, administered as a nasal spray, or instilled into the eyes. When administered into the eyes it will reduce redness, and when administered into the nose, it will stop it from running. </p>
<p>However, decongestants should be used for a short duration only and are not for long term use. In fact, if a nasal spray decongestant is used for more than five days, you can experience something called “rebound congestion”: a severe stuffy nose. </p>
<h2>Saline</h2>
<p>Saline (saltwater) nasal sprays or irrigation products are also available to flush out the allergens and provide hay fever relief. While there are not many studies in the area, there is evidence that saline irrigation <a href="https://www.cochrane.org/CD012597/ENT_nasal-saline-allergic-rhinitis#:%7E:text=Saline%20irrigation%20may%20reduce%20patient,any%20outcomes%20beyond%20three%20months">may reduce hay fever symptoms</a>. Saline is safe and is not associated with adverse effects.</p>
<p>If you’re suffering from hay fever symptoms and unsure what to try, talk to your prescriber or pharmacist, who can guide you through the options and identify the best one for your symptoms, medical conditions and medicines.</p>
<p>Allergen immunotherapy (or allergen shots) is another option hay fever sufferers <a href="https://www.allergy.org.au/patients/allergy-treatments/allergen-immunotherapy-faqs">may discuss</a> with their doctors. However it’s not a quick fix, with therapy taking three to five years.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/im-considering-allergen-immunotherapy-for-my-hay-fever-what-do-i-need-to-know-190408">I’m considering allergen immunotherapy for my hay fever. What do I need to know?</a>
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<img src="https://counter.theconversation.com/content/213071/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mary Bushell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Struggling with watery, itchy red eyes and a runny, congested nose? Here are your options for hay fever treatment.Mary Bushell, Clinical Assistant Professor in Pharmacy, University of CanberraLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2132692023-09-14T11:59:04Z2023-09-14T11:59:04ZPollen in pee: fossilised urine from a small African mammal helps us understand past environments<figure><img src="https://images.theconversation.com/files/547771/original/file-20230912-27-za8r9z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The lessons pollen can teach us are not to be sneezed at.</span> <span class="attribution"><span class="source">Elisa Manzati</span></span></figcaption></figure><p>If you are allergic to pollen, you are likely to curse the existence of these microscopic particles. You’re not alone: <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4829390/#:%7E:text=Allergies%20on%20the%20Rise,people%20worldwide%20affected%20by%20asthma">up to 30%</a> of the world’s population suffers from hay fever, which is often driven by pollen allergies. Shifting global climates are likely to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4829390/">push that figure even higher</a>.</p>
<p>However, pollen represents one of the most powerful tools to uncover the nature of past environmental change. </p>
<p>I am the head of the <a href="https://drlynnequick.com/nelson-mandela-palaeolab/">Palaeoecology Laboratory</a> at <a href="https://www.mandela.ac.za/">Nelson Mandela University</a> in South Africa. My research focuses on unravelling the secrets of ancient environments and ecosystems by examining fossil pollen grains. These tiny time capsules hold a wealth of information about the earth’s past. They help scientists to reconstruct ecosystems, track climate change and understand the evolution of plant life.</p>
<p>But it can be difficult to source pollen deposits in arid regions. That’s because such deposits are often found in large lakes, which are in short supply in southern Africa. That’s where an unlikely scientific ally enters the picture: the fossilised urine of a small mammal, the <a href="https://www.awf.org/wildlife-conservation/hyrax">rock hyrax</a> (South Africans call them “dassies”). </p>
<h2>Looking back</h2>
<p>Pollen grains are incredibly durable because they are made of an organic substance (called sporopollenin) that is very resistant to decay. Pollen is released into the air, often in large quantities, and can settle on surfaces like lakes, and become preserved in sediment deposits over thousands, or even millions, of years.</p>
<p>In the lab, we examine the pollen found in these deposits using a microscope. By identifying the different types of pollen grains found within the different layers (representing different time slices) we can reconstruct the area’s vegetation history. Plants grow under specific climatic conditions: for instance, desert plants can grow under low rainfall conditions whereas forest plants need high amounts of rainfall. So we can make inferences about the climate at the time that the pollen was incorporated into the deposit.</p>
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<img alt="A rather chubby small rodent with dark brown fur and protruding front teeth regards the photographer." src="https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/547484/original/file-20230911-23-arxq3p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The fossilised urine of rock hyraxes helps in the study of pollen.</span>
<span class="attribution"><span class="source">Kiev Victor</span></span>
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</figure>
<p>As I’ve said, southern Africa’s arid climates mean there are very few large lakes in the region. This makes it a challenge to source deposits that adequately preserve pollen within them over long periods of time. That’s where <a href="https://www.sciencedirect.com/science/article/abs/pii/S0277379112003319">fossilised dassie urine</a> comes in. </p>
<p>These sticky deposits called “middens” accumulate in rock crevices in mountainous areas over thousands to tens of thousands of years and contain beautifully preserved pollen grains. As they also contain various other types of evidence (such as geochemical data) and can be accurately dated, they represent the most valuable archive of past climate data in southern Africa. The oldest middens we’ve worked with date back 50,000 years.</p>
<h2>Ancient sites</h2>
<p>The research my lab conducts, focusing on harnessing the power of the humble pollen grain and utilising unique archives such as hyrax middens, is strongly multidisciplinary. It draws together elements from botany, geography, geology, climatology and archaeology. </p>
<p>We are currently generating fossil pollen records from several sites within the Cape Fold Belt mountains of South Africa. For example, we have a midden sequence that covers the last 6,000 years from the Baviaanskloof in the Eastern Cape province. The fossil pollen from this sequence shows that there was a dramatic shift in vegetation about 3,300 years ago, driven by a large fire event and increased temperatures. We’re hoping to publish this research soon.</p>
<p>This information provides baselines of variability in natural systems and can help inform current conservation efforts within the Baviaanskloof, which is a biodiversity hotspot. </p>
<p><a href="https://www.africanpaleoscienceslab.org/fieldwork/capp">Another project</a> that we are involved in is centred on the archaeological excavation within South Africa’s southern Cape region at a site called Boomplaas Cave. By using the fossil pollen within hyrax middens found within the vicinity of Boomplaas Cave, we hope to provide the environmental context to the archaeological record which can help to decipher how early humans responded to climate change.</p>
<h2>And looking forward</h2>
<p>We are not only working within the realm of the past: as pollen is one of the main sources of allergies it is important to monitor the types and amounts of pollen currently present in the air we breathe. My lab is part of the <a href="https://pollencount.co.za/">South African Pollen Monitoring network</a> and we generate pollen data for the city of Gqeberha in the Eastern Cape province. </p>
<p>This initiative focuses on analysing pollen captured in the air across several different parts of South Africa and ensuring that this information is publicly available. This project is particularly important as, <a href="https://journals.co.za/doi/abs/10.10520/EJC21714">due to climate change</a>, pollen seasons are lengthening and <a href="https://www.immunology.theclinics.com/article/S0889-8561(20)30061-8/fulltext">allergenic pollen is increasing</a>.</p><img src="https://counter.theconversation.com/content/213269/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lynne Quick receives funding from the National Research Foundation of South Africa: African Origins Platform and
GENUS: DSI-NRF Centre of Excellence in Palaeosciences
</span></em></p>Pollen can become preserved in sediment deposits over thousands, or even millions, of years.Lynne Quick, Senior Research Fellow, Nelson Mandela UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2067282023-06-23T15:19:49Z2023-06-23T15:19:49ZAI could democratise nutritional advice, but safety and accuracy must come first<figure><img src="https://images.theconversation.com/files/532735/original/file-20230619-28-bshxwb.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C5716%2C3796&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/balanced-nutrition-concept-clean-eating-flexitarian-1438074866">Antonina Vlasova / Shutterstock</a></span></figcaption></figure><p>When you search online to see how people are using artificial intelligence (AI) tools <a href="https://openai.com/blog/chatgpt">such as ChatGPT</a>, you will quickly find that food requests are popular. More specifically, users are seeking help with menu planning to meet their personal dietary goals.</p>
<p>But how effective is this technology in providing dietary advice? In a consumer poll, over <a href="https://www.food.gov.uk/sites/default/files/media/document/healthy-and-sustainable-diets-consumer-poll.pdf">three out of five consumers</a> agreed they would like to eat a healthier diet. Some 73% felt it was important to buy food that has a low environmental impact. </p>
<p>A substandard diet is a <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)32279-7/fulltext">leading cause of chronic disease and death</a> around the world. Additionally, a third of all human-caused greenhouse gas emissions are linked to food. Against this background, it’s clear that help is required to achieve the transformational shift from goals to behaviour. </p>
<p>However, for the <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/all.15560">19.9% of Europeans</a> who live with a self-reported food allergy, every eating decision has to align with protecting themselves from an adverse reaction. This comes at a cost: <a href="https://www.food.gov.uk/sites/default/files/media/document/FINAL%20OFF-SEN%20FHS%20Financial%20Cost%20Report.pdf">the average spend on weekly food purchases</a> for those with food hyper-sensitivities is 12-27% higher than for those with no allergies. An extra 40.37 days is required for those with allergies to research and plan their diet.</p>
<p>So, while AI could help many households have healthier diets, the consequences of an error for those with food allergies can be life threatening. With concern also raised for consuming purported healthy <a href="https://www.ahajournals.org/doi/epub/10.1161/CIRCULATIONAHA.119.043052">ingredients such as coconut oil</a>, it is extremely important that nutrition experts help inform these technological solutions.</p>
<h2>How can AI help?</h2>
<p>Academics in Canada <a href="https://www.sciencedirect.com/science/article/abs/pii/S0002916522105526">used specific types of AI</a>, known as natural language processing (NLP) and machine learning, to process text on food labels. This is done to accurately categorise food products by their specific nutritional criteria. </p>
<p>Such criteria include the Table of Reference Amounts for food categorisation used by Health Canada – the country’s government department for health policy – along with the nutrient profiling system of Food Standards Australia New Zealand, the authority that develops food standards for both Oceanian countries. This work showed that technology could be used to reduce the time needed to manually categorise large numbers of food products. </p>
<p>Commercial offerings using technology in this way already exist. One example is the company <a href="https://www.foodmaestro.me">Food Maestro</a>. The company I am involved with, <a href="https://www.spoon.guru">Spoon Guru</a>, has been working with global retailers for eight years, helping them facilitate the food search and find features within online grocery shopping platforms using AI systems that are co-developed with registered nutritionists.</p>
<p>The field of generative AI uses large language models (LLM) and machine learning to not only identify words within text but also to understand their order and context to produce human-like responses to text-based prompts. </p>
<p>AI chatbots such as Chat GPT use this technology to synthesise information, summarise text and answer questions. It can be used to provide tailored menu plans, generate recipe ideas and compile shopping lists. </p>
<h2>Chatbot test</h2>
<p>Early expert reviews using Chat GPT for menu planning and dietary advice have produced mixed results. <a href="https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4440144">A study</a> to assess the chatbot’s ability to produce dietary plans for those with allergies found that out of 56 diets, it generated an unsafe plan on one occasion, including almond milk within a nut-free dietary plan. </p>
<p>There were other errors too. For example, there were mistakes in the way food quantities and energy values were described and there was repetition of the same foods within menu plans. </p>
<p><a href="https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4440144">In a review</a> of ChatGPT’s potential for personalised obesity treatment, the authors raised concerns about patient privacy and security. They also noted a lack of accountability should harmful advice be provided. These models currently do not have to abide by professional standards or codes of ethics. </p>
<p><a href="https://www.researchgate.net/publication/369586435_ChatGPT_and_future_AI_chatbots_what_may_be_the_impact_on_Registered_Dietitian_Nutritionists">Dietitians tested ChatGPT’s ability</a> to define an ideal diet for those with type 2 diabetes or those undergoing haemodialysis – a treatment for kidney failure. They too found errors. The chatbot responded with foods that would not be optimal for these conditions, without any warnings. Menu plans were again repetitive and the authors raised concerns that such solutions could encourage users not to consult qualified health professionals. </p>
<p>The lack of references to the sources of information used to generate the answers meant they couldn’t check if they were of high scientific quality. <a href="https://www.linkedin.com/search/results/content/?fromMember=%5B%22ACoAACQnc4cBJ8o1rOAZhUoIulrr0VSb3wffDwI%22%5D&heroEntityKey=urn%3Ali%3Afsd_profile%3AACoAACQnc4cBJ8o1rOAZhUoIulrr0VSb3wffDwI&keywords=dariush%20mozaffarian&position=0&searchId=dbc7b4de-9965-4142-810a-0f8eeac13a66&sid=gkx&update=urn%3Ali%3Afs_updateV2%3A(urn%3Ali%3Aactivity%3A7064579900870942720%2CBLENDED_SEARCH_FEED%2CEMPTY%2CDEFAULT%2Cfalse)">A cardiologist</a> tested the advice that ChatGPT generated in relation to his specialist area, which was the link between dietary fat and cardiovascular disease. He felt the answers misinterpreted the research studies, repeatedly producing errors and inconsistencies in a tone described as sensible, confident and convincing.</p>
<h2>Ethical implications</h2>
<p>Despite clear signs that caution is warranted, some early reviews also noted that AI had strengths and the potential for providing personalised nutrition advice. ChatGPT’s responses often aligned with published food-based dietary guidelines. For example, the chatbot included fruit and vegetables in every meal, and incorporated advisory statements, such as “it is important to read labels carefully” and “consult a health professional”. </p>
<p>The ethical implications, safety and quality of the technology will need to be more fully understood before it is likely to be used within these professions. However, customers and patients may choose to make regular use of it regardless.</p>
<p>Technology like ChatGPT could be seen as a useful tool for dietitians and registered nutritionists to quickly find information about foods, helping inform their work. </p>
<p>Academics investigating the relationship between food and health could also use AI to <a href="https://www.sciencedirect.com/science/article/abs/pii/S0002916522106131">save time or develop innovative approaches</a> to their research. This could help increase the impact of their research, increasing its accessibility in a way that benefits society. </p>
<p>Policy makers, regulators and those working in the food industry are very interested in the health and sustainability of food. They are also interested in how advice in this area is communicated to the public. </p>
<p>Tools such as ChatGPT represent a whole new dimension of information and misinformation about food and health. The response to it will be crucial for ensuring the accurate, safe and transparent communication of dietary advice.</p>
<p>Using the technology could greatly increase access to personalised dietary advice for the general public. It could also help address the barriers individuals face in achieving their health goals. </p>
<p>However safety must come first. Nutrition experts, traceable sources of scientifically robust information and quality assurance processes need to be central to the development and implementation of such technologies when using them to provide dietary advice.</p><img src="https://counter.theconversation.com/content/206728/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Danielle McCarthy works part-time for Spoon Guru. She has previously received funding from UKRI, BBSRC, EIT, ESRC. She is also affiliated with Nutrition Talent. </span></em></p>AI chatbots can make a major contribution but we need to consider people with allergies.Danielle McCarthy, Honorary Professor of Practice, Queen's University Belfast, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2076662023-06-15T10:48:53Z2023-06-15T10:48:53ZWhy hay fever is so bad in the UK right now – and why thunderstorms make things worse for people with allergies and asthma<figure><img src="https://images.theconversation.com/files/531957/original/file-20230614-19-clcfua.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C7688%2C5121&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-allergy-infection-sneezing-shot-young-2157486261">Dragana Gordic/Shutterstock</a></span></figcaption></figure><p>The UK is in the grip of a particularly bad period for hay fever, with people across the nation experiencing a relentless onslaught of sneezing, itchy eyes and nasal congestion. Visits to the <a href="https://www.nhs.uk/conditions/hay-fever/">NHS hay fever advice page</a> have <a href="https://www.england.nhs.uk/2023/06/weekly-visits-to-nhs-websites-hay-fever-advice-reach-122000-as-pollen-levels-rise/">increased by 252%</a> since the beginning of May, signifying the magnitude of the problem.</p>
<p>This <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9993206/">common seasonal affliction</a> is a hypersensitive reaction to allergens, <a href="https://link.springer.com/article/10.1007/s40641-015-0018-2">most notably pollen</a>. Typically associated with spring and early summer, hay fever symptoms appear to have intensified in the UK in recent weeks. </p>
<p>The <a href="https://www.itv.com/news/2023-06-13/why-is-hay-fever-so-bad-this-year">question</a> on many people’s minds is: why is it so bad right now? A number of environmental factors may be contributing to the current hay fever havoc – including <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/cea.12709?casa_token=U5iXSibofjUAAAAA:7FUUOQNyS0JFnkiDa7SEK6c8-lvL_fMHcDsqSUby2b3E5QA0F-ECRyZ0EuMXc3NlbXY9a_I_-dZk02Wx">thunderstorms</a>, which can exacerbate symptoms for people with allergies as well as asthma.</p>
<p>Changes <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/all.13210">in weather patterns</a>, such as increasing temperatures and more intense rainfall, and extended flowering seasons as a result of these trends, can have a significant influence on pollen production.</p>
<p>In particular, higher <a href="https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.820">temperatures</a> and elevated atmospheric carbon dioxide levels, which are primarily occurring <a href="https://theconversation.com/yes-more-carbon-dioxide-in-the-atmosphere-helps-plants-grow-but-its-no-excuse-to-downplay-climate-change-130603">as a result of climate change</a>, have been shown to stimulate plant growth and <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0111712">enhance pollen production</a>.</p>
<p>It’s likely these factors are contributing to <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2222.2004.02061.x">longer pollen seasons</a> and higher concentrations of allergenic pollen in the air, explaining why people are reporting hay fever symptoms at such high levels.</p>
<h2>What about thunderstorms?</h2>
<p>Hot weather often paves the way <a href="https://science.howstuffworks.com/nature/climate-weather/storms/question646.htm">for thunderstorms</a>, and some parts of the UK have had severe storms <a href="https://www.bbc.co.uk/news/uk-65879069">in recent days</a>. </p>
<p>The interaction between thunderstorms and respiratory conditions can lead to <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/cea.12709?casa_token=U5iXSibofjUAAAAA:7FUUOQNyS0JFnkiDa7SEK6c8-lvL_fMHcDsqSUby2b3E5QA0F-ECRyZ0EuMXc3NlbXY9a_I_-dZk02Wx">heightened symptoms</a> – not only for people with hay fever, but for those with asthma as well. </p>
<p>The phenomenon of <a href="https://ukhsa.blog.gov.uk/2022/03/18/thunderstorm-asthma-and-public-health-looking-back-to-move-forward/">thunderstorm asthma</a> has been observed in various parts of the world, and is characterised by a sudden surge in asthma attacks and respiratory distress following a thunderstorm. </p>
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Read more:
<a href="https://theconversation.com/got-allergies-you-could-be-at-lower-risk-of-catching-covid-188486">Got allergies? You could be at lower risk of catching COVID</a>
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<p>We don’t yet fully understand the precise mechanisms underlying thunderstorm asthma, but it’s likely the contributing factors are similar to those which explain why thunderstorms can worsen allergy symptoms.</p>
<p>During thunderstorms, a process called <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1398-9995.2006.01271.x">pollen fragmentation</a> occurs, where rainwater breaks down pollen granules into smaller particles. These fragmented pollen particles are then <a href="https://www.jacionline.org/article/S0091-6749(17)30425-6/fulltext">dispersed into the air</a>, which can increase pollen concentrations. </p>
<p>Notably, due to their smaller size, these particles can <a href="https://www.tandfonline.com/doi/abs/10.1080/09603123.2011.574269?casa_token=PyIcL5Ruf9sAAAAA:Z_mueNBNagZsq2UV16QZkH3s2id80axwyPhHfq2SqiOkU1MYIlo71OcmK_49k8b6sav_uB0NP58v8g">penetrate deeper into our airways</a>. As a result, people with hay fever and asthma may face <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.2007.01393.x">more severe symptoms</a> after a thunderstorm when we’re exposed to these fragmented pollen particles, compared to intact pollen grains alone.</p>
<p>The process of pollen fragmentation during thunderstorms can also <a href="https://www.jacionline.org/article/S0091-6749(17)30425-6/abstract">release allergenic proteins</a>, making the pollen particles more potent. This can trigger more severe allergic responses in both asthma and hay fever sufferers.</p>
<p>Meanwhile, thunderstorms can also release irritant particles and pollutants, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3410145/">such as dust and ozone</a>, which can irritate the airways and exacerbate respiratory symptoms in people with asthma and hay fever.</p>
<figure class="align-center ">
<img alt="An umbrella in the rain." src="https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Thunderstorms can exacerbate hay fever and asthma.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/rain-drops-falling-black-umbrella-concept-323261750">Brian A. Jackson/Shutterstock</a></span>
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<p>These factors highlight <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1398-9995.2006.01271.x">the complex interplay</a> between environmental triggers, pollen characteristics and respiratory health in relation to hay fever and asthma. Understanding these mechanisms can hopefully help us in developing effective strategies for managing and mitigating the effects of these conditions.</p>
<h2>How can I manage my hay fever symptoms?</h2>
<p>Pollen levels look set <a href="https://www.metoffice.gov.uk/weather/warnings-and-advice/seasonal-advice/pollen-forecast#?date=2023-06-14">to remain high</a> across much of the UK in the coming days, and possibly for some time after that if the current weather conditions continue. If you’re struggling with hay fever symptoms, here are a few tips. </p>
<p><strong>Check the pollen count in your area:</strong> This information can be found through <a href="https://www.metoffice.gov.uk/weather/warnings-and-advice/seasonal-advice/pollen-forecast#?date=2023-06-13">the Met Office</a>, local weather forecasts, online pollen trackers, or smartphone apps. Adjust your activities and precautions accordingly. For example, on days when the pollen count is high, it’s a good idea to <a href="https://www.sciencedirect.com/science/article/abs/pii/S1081120610635016">stay indoors</a> where possible, with windows and doors closed, to minimise pollen exposure.</p>
<p><strong>Practice good hygiene:</strong> After spending time outdoors, <a href="https://www.nhs.uk/conditions/hay-fever/">take a shower and change your clothes</a> to remove any pollen that may have accumulated on your body or clothing. This reduces the likelihood of bringing pollen into your living spaces.</p>
<p><strong>Use filters:</strong> If you drive, consider investing in a pollen filter for your car’s ventilation system to reduce the amount of pollen that enters the vehicle while travelling. Additionally, using a <a href="https://www.sciencedirect.com/science/article/abs/pii/009167499090050E">high-efficiency particulate air (Hepa) filter</a> at home can help remove pollen and other allergens from indoor air.</p>
<p><strong>Avoid triggers:</strong> Refrain from mowing the lawn or spending prolonged periods in freshly cut grass, as this can stir up pollen particles. Similarly, keeping <a href="https://www.webmd.com/allergies/best-worst-plants">fresh flowers inside the house</a> can introduce additional allergens into the environment, so it’s best to avoid having these indoors during hay fever season.</p>
<p><strong>Create a barrier:</strong> Try applying <a href="https://www.nhs.uk/conditions/hay-fever/">petroleum jelly</a> around the nostrils. This creates a barrier that can trap pollen and reduce its entry into the nasal passages, thereby providing some relief.</p>
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Read more:
<a href="https://theconversation.com/future-hay-fever-seasons-will-be-worse-thanks-to-climate-change-34074">Future hay fever seasons will be worse thanks to climate change</a>
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<p>While these tips can help alleviate symptoms, it’s important to consult with a healthcare professional for personalised advice and treatment options. They can provide guidance on suitable medications, <a href="https://theconversation.com/hay-fever-how-immunotherapy-can-help-sufferers-not-getting-relief-from-the-usual-treatments-204945">immunotherapy</a>, or other interventions to help manage your hay fever or asthma effectively.</p><img src="https://counter.theconversation.com/content/207666/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A number of environmental factors, including thunderstorms, are likely to be contributing to the current hay fever havoc.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2049452023-05-18T16:36:02Z2023-05-18T16:36:02ZHay fever: how immunotherapy can help sufferers not getting relief from the usual treatments<figure><img src="https://images.theconversation.com/files/524393/original/file-20230504-19-pvcqsq.jpg?ixlib=rb-1.1.0&rect=60%2C0%2C6720%2C4476&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-hay-fever-allergy-sits-between-2129021987">Robert Kneschke/Shutterstock</a></span></figcaption></figure><p>It’s estimated that <a href="https://europepmc.org/article/med/17153005">up to 42%</a> of people suffer from hay fever symptoms, which can range from mild to severe.</p>
<p>While most hay fever sufferers will get relief from treatments such as antihistamines, nasal sprays, and eye drops, this is not the case for everyone. So it’s often overlooked as a minor annoyance, rather than the chronic condition it can be for some. </p>
<p>If you suffer badly with hay fever, and don’t find these traditional treatments helpful, you might be referred <a href="https://www.nhs.uk/conditions/hay-fever/">for immunotherapy</a>. This is a way of <a href="https://www.jacionline.org/article/S0091-6749(07)01461-3/fulltext">building the immune system’s tolerance</a> to allergens, by administering small, gradually increasing doses of the allergen through an injection, liquid drops or tablets. So how does it work?</p>
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Read more:
<a href="https://theconversation.com/hay-fever-can-sometimes-be-more-serious-than-we-think-this-is-why-we-should-know-our-treatment-options-194041">Hay fever can sometimes be more serious than we think. This is why we should know our treatment options</a>
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<p>When someone with hay fever comes into contact with an environmental allergen such as pollen, their immune system mistakes it as a threat and produces an antibody called <a href="https://bestpractice.bmj.com/topics/en-gb/232">immunoglobulin E</a>, or IgE, to neutralise it. </p>
<p>The IgE antibodies then bind to mast cells, a type of immune cells found in the nose, eyes and lungs. This triggers the release of histamine and other proteins and leads to the <a href="https://www.nhs.uk/conditions/hay-fever/">classic symptoms of hay fever</a>, including sneezing, runny nose, and itchy eyes. </p>
<p>Immunotherapy aims to induce a <a href="https://www.sciencedirect.com/science/article/abs/pii/S108112061100384X?casa_token=lo0I0dnJj2oAAAAA:ETHuaa42VsgrWlLY0RvEBA7V7FX1m7w2bQueL2HyVBta2pqPsuTjOR3mtzSadxNMdleEle8">shift in the immune response</a>, which leads to the production of antibodies that can neutralise the allergen and thereby prevent it from triggering the allergic reaction. </p>
<p>Additionally, immunotherapy induces T-regulatory cells. These special type of immune cells <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1765945/">prevent the release of inflammatory mediators</a> such as histamine.</p>
<p>Immunotherapy typically involves an <a href="https://www.jacionline.org/article/S0091-6749(07)01461-3/abstract">initial build-up phase</a>, which usually lasts around three to six months. During this time, the allergen doses are gradually increased, usually starting with a very low dose and increasing every week or two until a target dose is reached. </p>
<p>This is followed by a phase where the target dose is maintained to <a href="https://econtent.hogrefe.com/doi/abs/10.1024/1661-8157/a003971?journalCode=prx">sustain the immunological tolerance</a>. This maintenance phase can last for three to five years, or even longer. All phases are generally administered under guidance from an allergy specialist.</p>
<p>So immunotherapy can take several months or even years <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1765945/">to see the full benefits</a>. However, it can modify the underlying immune response to allergens and provide long-lasting relief from hay fever symptoms.</p>
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<img alt="A doctor and a patient." src="https://images.theconversation.com/files/524628/original/file-20230505-21-p9hzmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/524628/original/file-20230505-21-p9hzmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/524628/original/file-20230505-21-p9hzmh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/524628/original/file-20230505-21-p9hzmh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/524628/original/file-20230505-21-p9hzmh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/524628/original/file-20230505-21-p9hzmh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/524628/original/file-20230505-21-p9hzmh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Immunotherapy can provide long-lasting relief for many patients with hay fever.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/female-black-ethnicity-doctor-sits-her-1903115137">Lordn/Shutterstock</a></span>
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<h2>Sublingual immunotherapy</h2>
<p>While immunotherapy is commonly used to treat hay fever caused by pollen allergies, it can also be used to treat <a href="https://www.nature.com/articles/nri824">other types of allergies</a> such as food allergies, insect venom allergies, and allergies to medications.</p>
<p>Immunotherapy for people with hay fever is most commonly administered via injection (subcutaneous immunotherapy). The injection contains <a href="https://www.ncbi.nlm.nih.gov/books/NBK279487/">highly purified extracts</a> of specific pollens, or components of them. This is safe and evidence over many years has shown <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/alr.21141">it’s very effective</a>.</p>
<p>But a needle-free alternative is to give the allergen orally (sublingual immunotherapy). This method involves administering allergen extracts in the form of <a href="https://www.sciencedirect.com/science/article/abs/pii/S0091674901016189?casa_token=HJcDrb6aQR4AAAAA:OZ2E_7r0eWILFgOn9Cc-Hr3oj0VWcTqIurnyMIN2rC8kX4UNt8v0jWyGeYdAm6YCymek4CA">liquid drops or tablets under the tongue</a>. It requires fewer doctor visits than subcutaneous immunotherapy as it can be taken at home.</p>
<p>Although the oral method may be marginally less effective than the injections, it’s considered to be <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3206241/">slightly safer</a>. While uncommon, severe allergic reactions can occur during immunotherapy, and are more likely with subcutaneous immunotherapy. Fortunately, as this treatment takes place under the supervision of a healthcare professional, they can recognise and manage any adverse reactions.</p>
<h2>An effective alternative</h2>
<p>Like immunotherapy in general, sublingual immunotherapy is a course of treatment designed to <a href="https://www.jacionline.org/article/S0091-6749(07)01461-3/abstract">desensitise the immune system</a> to specific allergens that trigger hay fever symptoms. </p>
<p>Treatment typically starts a few months before the pollen season and a course of sublingual immunotherapy usually lasts for <a href="https://www.bsaci.org/wp-content/uploads/2021/05/BSACI-SLIT-SOP-2020-.pdf">around three years</a>. </p>
<p>In <a href="https://pubmed.ncbi.nlm.nih.gov/20934206/">one study</a>, patients who received sublingual immunotherapy for three, four or five years showed clinical benefit that persisted for up to eight years. </p>
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Read more:
<a href="https://theconversation.com/hay-fever-could-be-linked-to-our-gut-and-nose-bacteria-and-probiotics-may-help-symptoms-203855">Hay fever could be linked to our gut and nose bacteria – and probiotics may help symptoms</a>
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<p>Researchers have looked at the effectiveness of sublingual immunotherapy for hay fever by reviewing data from multiple randomised controlled trials. One <a href="https://pubmed.ncbi.nlm.nih.gov/15575924/">study from 2005</a> analysed 22 trials with 979 patients, while a <a href="https://pubmed.ncbi.nlm.nih.gov/21154351/">more recent review from 2010</a> looked at 60 trials with several thousand patients. </p>
<p>Both studies found that sublingual immunotherapy was effective in reducing symptoms and use of medications such as antihistamines. The research also showed that sublingual immunotherapy was effective for both seasonal and year-round allergies. It appears to be particularly effective for hay fever caused by <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8873945/">grass or tree pollens</a>.</p>
<p>However, results have been more variable <a href="https://pubmed.ncbi.nlm.nih.gov/15575924/">in children</a>.</p>
<p>Overall, the evidence suggests that sublingual immunotherapy is a safe and effective treatment option for hay fever in adults. Still, more research is needed to confirm the effectiveness of sublingual immunotherapy for specific pollens as well as its longer-term benefits.</p>
<h2>Not a quick fix</h2>
<p>Immunotherapy requires a commitment to regular treatments, and can take several months or <a href="https://pubmed.ncbi.nlm.nih.gov/15080830">even years to see the full benefits</a>. Additionally, not all patients respond equally well to this treatment, and it may not be a suitable option for everyone.</p>
<p>But immunotherapy can be a valuable tool for those seeking to reduce the frequency and severity of <a href="https://www.wsh.nhs.uk/CMS-Documents/Patient-leaflets/PaediatricDepartment/6437-1-Sublingual-immunotherapy.pdf">hay fever symptoms</a>. As with any medical treatment, it’s important to consult with a healthcare professional to determine the best treatment options for your individual needs.</p><img src="https://counter.theconversation.com/content/204945/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Sublingual immunotherapy reduces hay fever symptoms by changing the immune system’s response to allergens.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2038552023-04-21T14:53:28Z2023-04-21T14:53:28ZHay fever could be linked to our gut and nose bacteria – and probiotics may help symptoms<figure><img src="https://images.theconversation.com/files/522085/original/file-20230420-15-nvus1a.jpg?ixlib=rb-1.1.0&rect=17%2C0%2C5734%2C3837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many people suffer with hay fever.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/handsome-hipster-blowing-his-nose-on-287952305">wavebreakmedia/Shutterstock</a></span></figcaption></figure><p>For many people, spring has brought with it the dreaded symptoms of <a href="https://www.nhs.uk/conditions/hay-fever/">hay fever</a>, such as itchy eyes, sneezing and a stuffy nose. Hay fever is common, affecting <a href="https://europepmc.org/article/med/17153005">up to 42%</a> of people. It occurs when the immune system overreacts to allergens including pollen.</p>
<p>Research suggests there could be a link between <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5378446/">hay fever and the microbiome</a>, the collection of microorganisms that live in and on our bodies. Specifically, the composition of a person’s <a href="https://www.karger.com/Article/Abstract/510536">gut</a> and <a href="https://link.springer.com/article/10.1007/s00405-020-06311-1">nasal microbiomes</a> may play a role in the development of hay fever symptoms. </p>
<p>By exploring this connection, we can identify potential alternative treatments that may help reduce the effects of hay fever on people’s daily lives.</p>
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Read more:
<a href="https://theconversation.com/got-allergies-you-could-be-at-lower-risk-of-catching-covid-188486">Got allergies? You could be at lower risk of catching COVID</a>
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<h2>Hay fever and the microbiome</h2>
<p>Studies have shown that people with hay fever often have <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/all.13812">a less diverse gut microbiome</a> compared to those without the condition. Reduced diversity of gut bacteria can lead to an imbalance in the microbiome, and result in higher levels of inflammation (the body’s immune response to irritants, such as an allergens).</p>
<p>So the fact that reduced diversity of gut bacteria can lead to an increased risk of hay fever makes sense since the gut microbiome plays a key role in <a href="https://akjournals.com/view/journals/030/68/3/article-p135.xml">regulating the immune system</a>, and we know the immune system influences allergies. </p>
<p>The gut microbiome is thought to affect immune system function in several ways, including through the production of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9040132/">short-chain fatty acids</a>. These are produced by gut bacteria during the fermentation of dietary fibre (a part of normal digestion). </p>
<p>Short-chain fatty acids are known to have anti-inflammatory properties. Research has shown that lower levels of two bacterial strains which produce short-chain fatty acids – <em>Bifidobacterium</em> and <em>Lactobacillus</em> – are associated with <a href="https://pubmed.ncbi.nlm.nih.gov/21340202/">an increased risk of hay fever</a>.</p>
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Read more:
<a href="https://theconversation.com/hay-fever-why-some-people-suffer-from-it-and-others-dont-202553">Hay fever: why some people suffer from it and others don't</a>
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<p>In addition to the gut microbiome, hay fever also seems to be linked to the <a href="https://www.frontiersin.org/articles/10.3389/fcimb.2022.841995/full">nasal microbiome</a>, the community of microorganisms that inhabit the nasal passages. </p>
<p>The nasal microbiome plays an important role in regulating the immune system and protecting against harmful pathogens that enter our bodies through the nose. Imbalance and reduced diversity of the nasal microbiome can lead to an <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8566799/">increased risk of respiratory infections</a> and <a href="https://www.nature.com/articles/s41564-022-01301-x">exacerbation of hay fever symptoms</a>. </p>
<p>Studies have shown that people with hay fever often have a different <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4101129/">composition of their nasal microbiome</a> compared to those without the condition, with more of certain bacteria such as <em><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984262/">Staphylococcus aureus</a></em>. This imbalance in the nasal microbiome can lead to increased inflammation and a higher risk of certain hay fever symptoms.</p>
<h2>The potential role of probiotics and prebiotics</h2>
<p>Probiotics are <a href="https://academic.oup.com/ajcn/article/71/6/1682S/4729644?login=false">live microorganisms</a> which enhance the composition of “good” bacteria in the body. Prebiotics, meanwhile, are fibres that stimulate beneficial bacteria in the gut. Essentially, good bacteria <a href="https://www.healthline.com/nutrition/probiotics-and-prebiotics">feed on prebiotics</a>. Both are important for maintaining a healthy gut microbiome, which plays a crucial role in our overall health.</p>
<p>Several strains of <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/alr.21492">probiotic bacteria</a> have been studied in connection to hay fever.</p>
<p>One strain of interest is <em>Lactobacillus acidophilus</em>, which has been found to <a href="https://www.karger.com/Article/Abstract/515352">reduce hay fever symptoms</a> such as congestion, itching and sneezing. Another is <em>Lactobacillus rhamnosus GG</em>, which has shown potential in preventing hay fever development in infants.</p>
<p>Other <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1440-1711.2000.00886.x">strains</a> such as <em><a href="https://www.nature.com/articles/ejcn2012197">Bifidobacterium lactis</a></em>, <em>Bifidobacterium bifidum</em> and <em>Lactobacillus casei</em> have also shown some promise in reducing hay fever symptoms. But further research is needed.</p>
<h2>How does this work?</h2>
<p>Probiotics appear to modulate the immune response and in particular, decrease the production of inflammatory cytokines. These are signalling molecules produced by cells of the immune system that promote inflammation.</p>
<p>For example, <em>Lactobacillus acidophilus</em> can <a href="https://www.sciencedirect.com/science/article/pii/S0022030205727144">decrease the expression of</a> inflammatory cytokines associated with allergic inflammation in the mucous membranes in the nasal cavity. </p>
<p>Similarly, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8256161/"><em>Lactobacillus rhamnosus GG</em></a> has been shown to reduce airway hyperresponsiveness (where the airways narrow excessively in response to stimuli), decrease inflammatory cells in the lungs, and reduce inflammatory cytokines.</p>
<figure class="align-center ">
<img alt="Six different types of fermented food in jars." src="https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/522176/original/file-20230420-24-h28hpw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Fermented foods contain probiotics.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/set-fermented-food-great-gut-health-485504767">marekuliasz/Shutterstock</a></span>
</figcaption>
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<p>Prebiotics, such as fructo-oligosaccharides, have also been studied for their <a href="https://pubmed.ncbi.nlm.nih.gov/33376575/">potential in hay fever prevention</a>. They’ve been found to increase beneficial gut bacteria such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115998/"><em>Bifidobacterium</em> and <em>Lactobacillus</em></a>. One study showed that fructo-oligosaccharides supplementation in infants <a href="https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/specific-mixture-of-shortchain-galactooligosaccharides-and-longchain-fructooligosaccharides-induced-an-antiallergic-ig-profile-in-infants-at-risk-for-allergy/22B21443140E6A7F6956CC8F733492D0">decreased their risk</a> of developing hay fever. </p>
<h2>Incorporating probiotics and prebiotics</h2>
<p>If you suffer from hay fever, you may want to consider incorporating probiotics and prebiotics into your routine.</p>
<p>Probiotic supplements are widely available in various forms, including capsules, tablets, powders and drinks. It’s important to choose a supplement that contains the specific strains of probiotic bacteria that have been studied in relation to hay fever. These include <em>Lactobacillus acidophilus</em>, <em>Lactobacillus rhamnosus GG</em>, <em>Bifidobacterium lactis</em>, <em>Bifidobacterium bifidum</em> and <em>Lactobacillus casei</em>. </p>
<p>You can also incorporate <a href="https://www.webmd.com/digestive-disorders/ss/slideshow-probiotics">probiotic-rich foods</a> into your diet. These include fermented foods such as yogurt, kefir, sauerkraut, kimchi and kombucha.</p>
<p>As for prebiotics, fructo-oligosaccharides are <a href="https://www.webmd.com/diet/foods-high-in-prebiotic">commonly found in certain foods</a> such as bananas, onions, garlic, asparagus, artichokes and whole grains. Supplements are also available in various forms, including powders and capsules.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/probiotics-regulate-our-immune-system-and-could-help-fight-off-covid-new-research-175470">Probiotics regulate our immune system and could help fight off COVID – new research</a>
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<p>Sometimes, taking probiotics and prebiotics may have <a href="https://www.tandfonline.com/doi/abs/10.1517/14740338.2014.872627">side effects</a>, including digestive discomfort such as gas, bloating and diarrhoea. To minimise these risks, it’s recommended you start with a low dose and gradually increase this over time. It’s also worth consulting a healthcare provider before taking these supplements, especially if you have a medical condition or are on medications.</p><img src="https://counter.theconversation.com/content/203855/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research suggests there could be a link between hay fever and the microbiome. Exploring this connection paves the way for potential treatments.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2038812023-04-20T12:40:04Z2023-04-20T12:40:04ZAllergy season is getting more intense with climate change – we’re creating better pollen forecasts to help<figure><img src="https://images.theconversation.com/files/521940/original/file-20230419-28-qacnzc.jpg?ixlib=rb-1.1.0&rect=308%2C37%2C7230%2C4622&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Allergy season is here.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/teenage-girl-with-allergy-blowing-nose-royalty-free-image/1198047425">Imgorthand/E+ via Getty Images</a></span></figcaption></figure><p>If you’re feeling the misery of allergy season in your sinuses and throat, you’re probably wondering what nature has in store for you this time – and in the future.</p>
<p>Pollen allergies affect over <a href="https://doi.org/10.1016/j.anai.2010.10.014">30% of the global population</a>, making them a significant <a href="https://doi.org/10.1016/j.anai.2010.10.014">public health</a> and <a href="https://doi.org/10.1016/j.rmed.2010.05.006">economic issue</a> as people feel ill and miss work. Our research shows that, as greenhouse gases warm the planet, their effects are driving longer and more intense pollen seasons.</p>
<p>To help allergy sufferers manage their symptoms in our changing climate, we’re building better pollen forecasts for the future.</p>
<p>As <a href="https://scholar.google.com/citations?user=3dWPwz8AAAAJ&hl=en">atmospheric</a> <a href="https://clasp.engin.umich.edu/people/zhang-yingxiao/">scientists</a>, we study how the atmosphere and climate affect trees and plants. In a 2022 study, we found that the U.S. will face <a href="https://www.nature.com/articles/s41467-022-28764-0">up to a 200% increase</a> in total pollen this century if the world continues producing carbon dioxide emissions at a high rate. Pollen season in general will start up to 40 days earlier in the spring and last up to 19 days longer than today under that scenario.</p>
<figure class="align-center ">
<img alt="6 maps showing differences in how types of plant pollen seasons will change. _Ambrosia_, better known as ragweed, has the greatest increase." src="https://images.theconversation.com/files/451986/original/file-20220314-117573-11rcxij.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/451986/original/file-20220314-117573-11rcxij.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=604&fit=crop&dpr=1 600w, https://images.theconversation.com/files/451986/original/file-20220314-117573-11rcxij.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=604&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/451986/original/file-20220314-117573-11rcxij.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=604&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/451986/original/file-20220314-117573-11rcxij.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=759&fit=crop&dpr=1 754w, https://images.theconversation.com/files/451986/original/file-20220314-117573-11rcxij.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=759&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/451986/original/file-20220314-117573-11rcxij.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=759&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The maps on the left show the recent average pollen season length in days for three types of plants: <em>Platanus</em>, or plane trees, such as sycamores; <em>Betula</em>, or birch; and <em>Ambrosia</em>, or ragweed. The maps on the right show the expected changes in total days by the end of the century if carbon dioxide emissions continue at a high rate.</span>
<span class="attribution"><a class="source" href="https://www.nature.com/articles/s41467-022-28764-0">Zhang and Steiner, 2022</a></span>
</figcaption>
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<p>While most studies focus on pollen overall, we zoomed in on more than a <a href="https://www.nature.com/articles/s41467-022-28764-0">dozen different types of grasses and trees</a> and how their pollen will affect regions across the U.S. in different ways. For example, species like oak and cypress will give the Northeast the biggest increase, but allergens will be on the rise just about everywhere, with consequences for human health and the economy.</p>
<h2>Why pollen is increasing</h2>
<p>Let’s start with the basics. Pollen – the dustlike grains produced by grasses and plants – contains the male genetic material for a plant’s reproduction.</p>
<p>How much pollen is produced depends on how the plant grows. Rising global temperatures will boost plant growth in many areas, and that, in turn, will affect pollen production. </p>
<p>Warmer temperatures will extend the growing season, allowing plants to grow and emit pollen for longer periods. But temperature is only part of the equation. We found that <a href="https://www.nature.com/articles/s41467-022-28764-0">a potentially greater driver of the future pollen increase</a> will be rising carbon dioxide emissions from sources such as vehicles and power plants. Carbon dioxide fuels photosynthesis, leading to increased growth and the potential for more pollen production. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/451965/original/file-20220314-16-1h5t3qc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Dust-like pollen falls from pine cones" src="https://images.theconversation.com/files/451965/original/file-20220314-16-1h5t3qc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/451965/original/file-20220314-16-1h5t3qc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/451965/original/file-20220314-16-1h5t3qc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/451965/original/file-20220314-16-1h5t3qc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/451965/original/file-20220314-16-1h5t3qc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/451965/original/file-20220314-16-1h5t3qc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/451965/original/file-20220314-16-1h5t3qc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Cones on a Norway spruce in Virginia release pollen.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:2021-04-17_10_43_13A_Pollen_cones_releasing_pollen_on_a_Norway_Spruce_along_Tranquility_Court_in_the_Franklin_Farm_section_of_Oak_Hill,_Fairfax_County,_Virginia.jpg">Famartin/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>Pollen changes will vary by region</h2>
<p>We looked at 15 different pollen types, rather than treating all pollen the same as many past studies have. Our study found that the amount of pollen increase in a specific region depends on the types of vegetation.</p>
<p>Typically, pollination starts with leafy deciduous trees in late winter and spring. Alder, birch and oak are the three top deciduous trees for causing allergies, though there are others, like mulberry. Grass pollen becomes more prevalent in the summer, followed by ragweed in late summer. In the Southeast, evergreen trees like mountain cedar and juniper (in the cypress family) start in January. In Texas, “cedar fever” is the equivalent of hay fever.</p>
<p>We found that in the Northeast, pollen seasons for a lot of allergenic trees will <a href="https://www.nature.com/articles/s41467-022-28764-0">increasingly overlap</a> as temperatures and carbon dioxide emissions rise. For example, it used to be that maple trees would release pollen first, and then birch would pollinate. Now we see more overlap of their pollen seasons.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/2OsicNwv9jE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How pollen season spreads across the U.S. over one year. Yingxiao Zhang and Allison Steiner.</span></figcaption>
</figure>
<p>In general, pollen season changes are greater in the northern United States than in the South, because of larger temperature increases in northern areas in future climate projections.</p>
<p>Southeastern regions, including Florida, Georgia and South Carolina, can expect large grass and weed pollen increases in the future. The Pacific Northwest is likely to see peak pollen season a month earlier because of the early pollen season of alder. </p>
<p>Allergy problems are already on the rise. A study in 2021 found that the <a href="https://theconversation.com/pollen-can-raise-your-risk-of-covid-19-and-the-season-is-getting-longer-thanks-to-climate-change-156754">overall pollen season</a> was already about <a href="https://doi.org/10.1073/pnas.2013284118">20 days longer in North America</a> than it was in 1990 and pollen concentrations were up about 21%.</p>
<h2>Silver lining: We can improve pollen forecasting</h2>
<p>Most pollen forecasts right now provide a very broad estimate of where and when pollen counts will be high. Part of the problem is that there aren’t many <a href="https://pollen.aaaai.org/#/">observing stations</a> for pollen counts. Most are run by allergy clinics, and there are fewer than 200 of these stations distributed across the country. Michigan, where we live, doesn’t have any that are currently operating.</p>
<p>It’s a very labor-intensive process to measure different types of pollen. As a result, current forecasts have a lot of uncertainties. These likely are based in part on what a station has observed in the past and the weather forecast.</p>
<figure class="align-center ">
<img alt="A person's hands jostle a pine branch to collect pollen" src="https://images.theconversation.com/files/451976/original/file-20220314-117573-o3yi1v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/451976/original/file-20220314-117573-o3yi1v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/451976/original/file-20220314-117573-o3yi1v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/451976/original/file-20220314-117573-o3yi1v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/451976/original/file-20220314-117573-o3yi1v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/451976/original/file-20220314-117573-o3yi1v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/451976/original/file-20220314-117573-o3yi1v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Pollen sampling for regional forecasts can be labor-intensive.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Pollen_collection.jpg">HelenaAnna/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Our model, <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022MS003329">if integrated into a forecasting framework</a>, could provide more targeted pollen forecasts across the country.</p>
<p>We can estimate where the trees are from satellite data and on-the-ground surveys. We also know how temperature influences when pollen comes out – what scientists call the <a href="https://www.britannica.com/science/phenology">phenology</a> of the pollen. With that information, we can use meteorological factors like wind, relative humidity and precipitation to figure out how much pollen gets into the air, and atmospheric models can show how it moves and blows around, to create a real-time forecast.</p>
<p>We’re currently working with a <a href="https://www.noaa.gov/">National Oceanic and Atmospheric Administration</a> lab about ways to integrate that information into a tool for air quality forecasting. Our next step is to evaluate these forecast tools and make information available to the public.</p>
<figure class="align-center ">
<img alt="Dozens of round, spiky pollen grains attached to a plant" src="https://images.theconversation.com/files/452085/original/file-20220315-19-guleto.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/452085/original/file-20220315-19-guleto.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/452085/original/file-20220315-19-guleto.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/452085/original/file-20220315-19-guleto.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/452085/original/file-20220315-19-guleto.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/452085/original/file-20220315-19-guleto.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/452085/original/file-20220315-19-guleto.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ragweed pollen grains, magnified and colorized.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/ragweed-pollen-royalty-free-image/529469522">Bob Sacha/Corbis Documentary via Getty Images</a></span>
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</figure>
<p>There are still some unknowns when it comes to long-term pollen projections. For example, scientists don’t fully understand why plants produce more pollen in some years than others, and currently we cannot include these changes in our models. It’s also not fully clear how plants will respond if carbon dioxide levels go through the roof. Ragweed and residential trees are also hard to capture. There are very few ragweed surveys showing where these plants are growing in the U.S., but that can be improved.</p>
<p><em>This is an update to <a href="https://theconversation.com/pollen-season-is-getting-longer-and-more-intense-with-climate-change-heres-what-allergy-sufferers-can-expect-in-the-future-179158">an article</a> originally published March 15, 2022.</em></p><img src="https://counter.theconversation.com/content/203881/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Allison L. Steiner has received funding from NSF, NASA, DOE, and NOAA. She is currently the President of the Atmospheric Sciences section of the American Geophysical Union.</span></em></p><p class="fine-print"><em><span>Yingxiao Zhang does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Rising temperatures mean longer, earlier pollen seasons, but a bigger problem is what more carbon dioxide will do to the amount of pollen being released.Yingxiao Zhang, Ph.D. Student in Atmospheric Science, University of MichiganAllison L. Steiner, Professor of Atmospheric Science, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2025532023-03-30T15:20:57Z2023-03-30T15:20:57ZHay fever: why some people suffer from it and others don’t<figure><img src="https://images.theconversation.com/files/518169/original/file-20230329-28-d70vsm.jpg?ixlib=rb-1.1.0&rect=0%2C11%2C7360%2C4891&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/vibrant-blonde-middle-aged-woman-sneeze-622469891">Octa corp/Shutterstock</a></span></figcaption></figure><p>While the arrival of spring brings blooming flowers and trees, it also marks the beginning of allergy season for many people. Those who suffer from hay fever may start to notice <a href="https://www.nhs.uk/conditions/hay-fever/">familiar symptoms</a> such as sneezing, itchy eyes and a runny nose. </p>
<p>Hay fever, also known as allergic rhinitis, affects up to <a href="https://europepmc.org/article/med/17153005">42% of people</a> and can significantly impact their quality of life during the spring and summer months.</p>
<p>When a person with hay fever comes into contact with an allergen (pollen), their immune system mistakenly identifies it as a threat and produces an antibody called <a href="https://bestpractice.bmj.com/topics/en-gb/232">immunoglobulin E</a>, or IgE, to neutralise it. The IgE antibodies then attach themselves to a type of immune cells called mast cells, which are found in the nose, eyes and lungs. </p>
<p>When the allergen comes into contact with the IgE antibodies on the mast cells, it triggers the release of histamine and other proteins, causing inflammation and the symptoms of hay fever.</p>
<p>But why do so many people get hay fever, while others don’t? There are a range of factors at play.</p>
<h2>Genetics, immunity and the environment</h2>
<p>Genetic factors play a significant role in determining a person’s <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3151648/">susceptibility to hay fever</a>. Several genes, including those involved in immune system regulation and response, have been linked to an increased risk of developing hay fever. </p>
<p>Research has shown that the heritability – that is, the degree to which differences in people’s genes account for variations in their traits – ranges from <a href="https://www.frontiersin.org/articles/10.3389/fgene.2020.00270/full">33% to 91%</a> for hay fever. So, if people in your family have hay fever, you’re more likely to have it too.</p>
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Read more:
<a href="https://theconversation.com/do-i-have-covid-or-hay-fever-heres-how-to-tell-188030">Do I have COVID or hay fever? Here’s how to tell</a>
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<p>Some people’s immune systems <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3573758/">may overreact to allergens</a>, leading to an allergic response and the development of hay fever. In fact, having other allergies, asthma, allergic dermatitis or eczema can <a href="https://www.mayoclinic.org/diseases-conditions/hay-fever/symptoms-causes/syc-20373039">increase your risk</a> of developing hay fever.</p>
<p>Environmental factors such as exposure to <a href="https://acaai.org/allergies/allergic-conditions/hay-fever/">air pollution, tobacco smoke and other irritants</a> may also make a person more susceptible to hay fever. This can be due to damage to the nasal passages and respiratory system, making it easier for allergens to enter the body and trigger an allergic response. Similarly, <a href="https://bmcpediatr.biomedcentral.com/articles/10.1186/1471-2431-10-61">exposure to second-hand smoke</a> in early life is a risk factor for later development of hay fever.</p>
<p>Some people may be <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5346329/">exposed to allergens</a> more frequently or in larger amounts than others, making them more susceptible to developing hay fever. This can be due to living in an area with high levels of pollen or being exposed to certain allergens at work, for example.</p>
<h2>Why can symptoms be worse in some seasons more than others?</h2>
<p>The amount of pollen or other allergens in the air can vary from year to year and season to season. In some years, the pollen count may be higher, leading to more severe hay fever symptoms.</p>
<p>Weather conditions, such as temperature, humidity and wind, <a href="https://link.springer.com/article/10.1007/s00484-017-1457-3">can affect</a> the amount and distribution of pollen in the air. A rainy spring may wash away some of the pollen, while a warm, dry summer may lead to more pollen production.</p>
<p>The body’s immune system can also change over time, which can affect how it responds to allergens. This means someone who had severe hay fever symptoms in the past may experience milder symptoms as they get older.</p>
<p>Indeed, hay fever can develop at any age, but it’s more common in <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/all.12002?casa_token=PWxI6ub0HtcAAAAA:a4GPzguEcA3aYK9Fu52clDTxPGFXsDuWml80jtViPIg8ilQDIcgOj58wwxcShXoz6q2br7L6eDAQ">children and young adults</a>. As a person ages, their immune system may become less reactive to allergens, leading to <a href="https://www.karger.com/article/Abstract/237398">a reduction in hay fever symptoms</a>.</p>
<figure class="align-center ">
<img alt="A young boy rubs his eyes." src="https://images.theconversation.com/files/518172/original/file-20230329-14-vosz9f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/518172/original/file-20230329-14-vosz9f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/518172/original/file-20230329-14-vosz9f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/518172/original/file-20230329-14-vosz9f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/518172/original/file-20230329-14-vosz9f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/518172/original/file-20230329-14-vosz9f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/518172/original/file-20230329-14-vosz9f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Hay fever is common in children.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/boy-rubbing-eye-child-pollen-allergy-2155315549">Dragana Gordic/Shutterstock</a></span>
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</figure>
<p>People may be exposed to different allergens in <a href="https://link.springer.com/article/10.1007/s00484-017-1457-3">different years or seasons</a>, which can affect the severity of their symptoms. For example, someone who is allergic to grass pollen will be triggered at different times to those triggered by certain tree pollen.</p>
<p>Lifestyle factors such as stress, diet and exercise <a href="https://www.sciencedirect.com/science/article/pii/S0006899314014735?casa_token=H5zT4lQU1WwAAAAA:BiRy8aE-6zJT08dG5V5SDgo451zVC1wUFsAw67n0VwWXB58anEQ9n_rR5iiXyTLycoqT-2o">can affect the immune system</a> and may contribute to the severity of hay fever symptoms. For example, stress can weaken the immune system, making it <a href="https://www.immunology.theclinics.com/article/S0889-8561(10)00080-9/fulltext">more susceptible to allergens</a>. </p>
<p>Climate change is also altering the quantity and composition <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/all.14476">of pollen</a> that plants release, as well as the timing. Increasing temperatures and atmospheric carbon dioxide levels are causing some plants <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2222.2004.02061.x">to produce more pollen</a>, while other species are shifting their flowering periods to earlier in the year. This means pollen seasons are starting earlier, lasting longer, and becoming more intense.</p>
<h2>Tips for managing hay fever</h2>
<p><strong>Avoid allergens:</strong> Try to <a href="https://www.uptodate.com/contents/trigger-avoidance-in-allergic-rhinitis-beyond-the-basics">avoid exposure to allergens</a> that trigger your hay fever symptoms. This may mean staying indoors during high pollen counts or wearing a mask if you’re working outdoors.</p>
<p><strong>Use air filters:</strong> Consider using <a href="https://www.sciencedirect.com/science/article/pii/S0091674909013177?casa_token=CkTL0kWie5kAAAAA:yvBLfFgn9XJPlenxxkLdy4zPxxbXRorx0dDamOIaE6oYYlg4o_o0xn4Ay9IzbhcsJSpF1dE">Hepa (high-efficiency particulate air) air filters</a> in your home or workplace to help remove allergens from the air. </p>
<p><strong>Keep windows closed:</strong> <a href="https://www.nhs.uk/conditions/hay-fever/">Closing windows</a> during high pollen counts will prevent allergens from entering your home.</p>
<p><strong>Take antihistamines:</strong> These are <a href="https://www.nhs.uk/medicines/cetirizine/">medications</a> that help reduce hay fever symptoms by blocking the effects of histamine, which is released during an allergic reaction.</p>
<p><strong>Consider immunotherapy:</strong> <a href="https://www.ncbi.nlm.nih.gov/books/NBK279487/">Immunotherapy</a>, also known as allergy shots, can help reduce hay fever symptoms by desensitising your immune system to specific allergens over time.</p>
<p><strong>Manage stress:</strong> Stress <a href="https://journals.sagepub.com/doi/pdf/10.1177/1559827610395467?casa_token=FsgTLcz27JEAAAAA:7DCZvxNdzd184MqZ2VLQ5rmaZQ6vU00NUJ6UR8fLDeX6YrEBf43gst7eUMp30OrA5qc6hjAJfQ">can make hay fever symptoms worse</a>, so try to manage it through techniques such as meditation, yoga or deep-breathing exercises.</p>
<p>It’s important to talk to your doctor before starting any new medications or treatments for hay fever.</p><img src="https://counter.theconversation.com/content/202553/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Our genetics, immune systems and conditions in the environment around us can all play a role in susceptibility to hay fever.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1925702022-12-08T13:32:46Z2022-12-08T13:32:46ZPeople can have food sensitivities without noticeable symptoms – long-term consumption of food allergens may lead to behavior and mood changes<figure><img src="https://images.theconversation.com/files/499637/original/file-20221207-18-b6a7kw.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2121%2C1412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Asymptomatic sensitization may lead people to continue consuming food allergens, causing hidden neurological issues.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-woman-in-striped-shirt-from-back-choosing-royalty-free-image/1357286617">Garetsworkshop/iStock via Getty Images Plus</a></span></figcaption></figure><p>The prevalence of food allergies is increasing worldwide, <a href="https://doi.org/10.1111/j.1399-3038.2011.01145.x">approaching an epidemic level</a> in some regions. In the U.S. alone, <a href="https://www.foodallergy.org/resources/facts-and-statistics">approximately 10% of children and adults</a> suffer from food allergies, with allergies to cow’s milk, eggs, peanuts and tree nuts being the most common. Some patients have mild symptoms that might not need medical attention, leaving these cases unreported. </p>
<p>Food allergies, or food hypersensitivities, result from the overreaction of the immune system to typically harmless proteins in food. They can manifest as a <a href="https://acaai.org/allergies/allergic-conditions/food/">spectrum of symptoms</a>, ranging from itching, redness and swelling for milder reactions, to vomiting, diarrhea, difficulty breathing and other potentially life-threatening symptoms for severe reactions.</p>
<p>Besides self-reporting, food allergies can be <a href="https://acaai.org/allergies/testing-diagnosis/">diagnosed by exposing patients</a> to trace amounts of offending proteins, or allergens, via their mouth or skin and observing their immediate reactions. More commonly, doctors use blood tests to measure the levels of <a href="https://www.aaaai.org/tools-for-the-public/allergy,-asthma-immunology-glossary/immunoglobulin-e-(ige)-defined">immunoglobulin E, or IgE</a>, a specialized antibody that the immune system uses to identify allergens and trigger a response. Although healthy individuals may have low levels of IgE in the blood, patients with food allergies have much higher levels that increase their risk of having severe allergic reactions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/499636/original/file-20221207-16-gmhxjg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Patient undergoing skin-prick allergy test on arm" src="https://images.theconversation.com/files/499636/original/file-20221207-16-gmhxjg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/499636/original/file-20221207-16-gmhxjg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/499636/original/file-20221207-16-gmhxjg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/499636/original/file-20221207-16-gmhxjg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/499636/original/file-20221207-16-gmhxjg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/499636/original/file-20221207-16-gmhxjg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/499636/original/file-20221207-16-gmhxjg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Skin-prick allergy tests involve exposing patients to trace amounts of an allergen and observing their reactions.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/immunologist-doing-skin-prick-allergy-test-on-a-royalty-free-image/1288998568">ronstik/iStock via Getty Images</a></span>
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<p>But <a href="https://doi.org/10.1159%2F000517824">some people</a> who test positive on skin-prick allergy tests with moderate increases in IgE don’t notice any allergy-related symptoms when they eat the allergen. This condition is sometimes referred to as <a href="https://www.verywellhealth.com/what-is-sensitization-82988">asymptomatic sensitization</a>. In many cases, people with this condition may not even be aware that they have a food hypersensitivity. </p>
<p>Are they truly asymptomatic, though? Or are there effects within their body that they aren’t aware of?</p>
<p>I am a <a href="https://scholar.google.com/citations?user=kXRRwk4AAAAJ&hl=en">neuroscientist</a> studying how the brain is affected by food allergies. I became interested in this topic when I found that some of my family members had a hypersensitivity to cow’s milk. Some totally avoid dairy products because they have experienced severe, life-threatening symptoms. Those who don’t have typical allergic reactions occasionally eat dairy, but appear to develop seemingly unrelated illnesses a day or two later.</p>
<p>What I and other researchers have found is that food allergens can affect your brain and behavior if you’re hypersensitized, even if you don’t have typical food allergy symptoms.</p>
<h2>Food allergies linked to behavioral disorders</h2>
<p>Researchers have suspected food hypersensitivities to be a potential cause for behavioral disorders for decades.</p>
<p>A <a href="https://doi.org/10.1097/00007611-194908000-00017">1949 case report</a> described behavioral and mood disturbances in patients after they ate certain foods, such as milk and eggs. Their symptoms improved after removing the suspected foods from their diet, suggesting that a food hypersensitivity was the likely culprit. However, I was intrigued that the patients had been able to eat the offending foods up until they chose to avoid them. In other words, they were asymptomatically sensitized, or tolerant, to the allergens.</p>
<p>Several recent studies in people have supported the association between food allergies and various neuropsychiatric disorders, including <a href="https://doi.org/10.1111/all.12829">depression, anxiety</a>, <a href="https://doi.org/10.1016/j.aller.2016.03.001">attention-deficit/hyperactivity disorder</a> and <a href="https://doi.org/10.1002/aur.2106">autism</a>. They strengthen the possibility that some reactions to food allergens could involve the nervous system and manifest as behavioral disorders.</p>
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<figcaption><span class="caption">The food you eat can affect your brain in many ways.</span></figcaption>
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<p>However, the idea of food hypersensitivity causing neuropsychiatric disorders is still controversial because of inconsistencies across studies. Differences in the types of allergies, ethnic backgrounds, dietary habits and other factors among the study participants can produce conflicting results. More importantly, some studies included those with self-reported food allergies, while others included only those with lab-confirmed food allergies. This limited investigations to only symptomatic individuals.</p>
<h2>Food hypersensitivity, brain and behavior</h2>
<p><a href="https://doi.org/10.1016/j.bbi.2021.03.002">My laboratory tested</a> whether food allergens could manifest as behavioral symptoms, particularly in asymptomatically sensitized individuals. We wanted to find out whether eating offending foods could lead to brain inflammation and behavioral changes after sensitization, even in the absence of other obvious severe reactions.</p>
<p>To minimize the individual differences found in human studies, we decided to work with mice. We sensitized mice of the same age and genetic background to the common milk allergen β-lactoglobulin, or BLG, and fed them the same diet in the same room. We found that while <a href="https://doi.org/10.1016/j.bbi.2021.03.002">BLG-sensitized mice</a> produced moderately but significantly elevated levels of IgE, they did not show immediate allergic reactions. They could even eat food containing the milk allergen for two weeks without showing any obvious symptoms, despite maintaining elevated levels of IgE. This indicated that they were asymptomatically sensitized.</p>
<p>We then observed whether they showed any changes in emotionally driven behavior. Because we could not ask mice how they felt, we deduced their “feelings” by noting changes from their normal, survival-oriented behavior. Mice instinctively explore their environment to search for food and shelter while avoiding potential danger. However, “anxious” mice tend to spend more time hiding to play it safe. We identified “depressed” mice by briefly holding them by the tail. Most mice will keep fighting to get out of the uncomfortable predicament, while depressed mice quickly give up.</p>
<p>Our experiments were designed to simulate situations where asymptomatically sensitized individuals would eat either a large amount of an offending food in one day or small amounts every day for a few weeks. We mimicked these situations by placing a large amount of the milk allergen directly into the stomach of sensitized mice with a feeding tube, or giving them an allergen-containing mouse chow to eat the allergen a little at a time.</p>
<p>Interestingly, BLG-sensitized mice showed <a href="https://doi.org/10.1016/j.bbi.2021.03.002">anxiety-like behavior</a> one day after receiving a large amount of the allergen. Another group of sensitized mice developed <a href="https://doi.org/10.3390/cells11040738">depression-like behavior</a> after eating small amounts of allergen for two weeks. In addition, BLG-sensitized mice showed signs of brain inflammation and neuronal damage, suggesting that changes in the brain may be responsible for their behavioral symptoms.</p>
<p>We also investigated the <a href="https://doi.org/10.3389/falgy.2022.870628">long-term effect</a> of allergen consumption by keeping BLG-sensitized mice on the allergen-containing diet for one month. We found that IgE levels declined in sensitized mice by the end of the month, indicating that continually eating small amounts of the allergen led to decreased immune responses, or “desensitization.” In contrast, signs of brain inflammation remained, suggesting that the harmful effect of allergens persisted in the brain.</p>
<h2>Chronic brain inflammation</h2>
<p>Researchers have yet to study prolonged brain inflammation, or neuroinflammation, in people who are asymptomatically sensitized. In general, though, <a href="https://doi.org/10.1172/JCI90609">chronic neuroinflammation</a> is a known contributor to neurodegenerative diseases, such as multiple sclerosis and Alzheimer’s disease, although the exact causes of these diseases are unknown. A better understanding of the role allergens play in neuroinflammation can help researchers clarify whether food allergens trigger chronic inflammation that can lead to these diseases.</p>
<p>This knowledge could be especially important for patients undergoing <a href="https://www.aaaai.org/Tools-for-the-Public/Allergy,-Asthma-Immunology-Glossary/Oral-Immunotherapy-Defined">oral immunotherapy</a>, an approach to allergy treatment that involves incrementally ingesting small amounts of allergens over time. The goal is to desensitize the immune system and reduce the incidence of anaphylaxis, or life-threatening allergic reactions. In 2020, the U.S. Food and Drug Administration <a href="https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-treatment-peanut-allergy-children">approved a standardized form of peanut allergens</a> to prevent anaphylaxis in eligible pediatric patients. However, its possible long-term effect on the nervous system is unknown.</p>
<p>Food allergens can affect the brain and behavior of seemingly asymptomatic people, making them not so asymptomatic neurologically. Considering how your brain responds to the food you eat puts a whole new meaning to the phrase “you are what you eat.”</p><img src="https://counter.theconversation.com/content/192570/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kumi Nagamoto-Combs receives funding from the National Institute of Allergy and Infectious Disease and the National Institute on Aging. </span></em></p>Food allergies have been linked to behavioral and mood disorders, including depression, anxiety and ADHD.Kumi Nagamoto-Combs, Assistant Professor of Biomedical Sciences, University of North DakotaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1940412022-11-09T00:25:16Z2022-11-09T00:25:16ZHay fever can sometimes be more serious than we think. This is why we should know our treatment options<figure><img src="https://images.theconversation.com/files/493724/original/file-20221107-11-xo27jm.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C7054%2C3537&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sick-woman-sneezing-blowing-nose-photo-1366461485">shutterstock</a></span></figcaption></figure><p>Hay fever (also known as allergic rhinitis) is a catch-all term that covers a group of ailments that cause sneezing, a runny nose, and itchy and red eyes.</p>
<p>Hay fever affects <a href="https://www.aihw.gov.au/getmedia/f155276c-b1c1-4bb9-94de-e7e09555bce4/13567.pdf.aspx?inline=true">millions</a> of people in Australia. Ask your friends and colleagues about hay fever and chances are several will report they have it. However, they will probably describe different triggers, symptoms and <a href="https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/guide-to-common-allergenic-pollen">seasons</a> when it occurs. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1590076998306566145"}"></div></p>
<p>Although it may seem like more of an annoyance than anything else, uncontrolled hay fever can have <a href="https://www.sciencedirect.com/science/article/abs/pii/S0091674997800425">economic</a> and further health effects. </p>
<p>Hay fever can reduce people’s ability to concentrate, for example when driving or at <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3904041/">work</a> or <a href="https://pubmed.ncbi.nlm.nih.gov/17560637/">school</a>. This is made worse with hay fever also leading to <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/410859">disturbed sleep</a>, affecting <a href="https://aacijournal.biomedcentral.com/articles/10.1186/s13223-021-00615-5">mood</a>.</p>
<p>Nasal inflammation from allergies also has a concerning impact on an individual’s defences against infection. The inflammation from hay fever and the need to mouth breathe has a direct <a href="https://thorax.bmj.com/content/67/7/582.short">impact on asthma</a>, leading to worse symptom control and a greater risk of a flare-up that requires unscheduled health care.</p>
<p>To reduce these risks, a range of treatments are available. However, before considering treatment, we need to consider what’s going wrong and why.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/lush-grasslands-higher-allergy-risks-what-hay-fever-sufferers-can-expect-from-another-la-nina-season-189982">Lush grasslands, higher allergy risks – what hay fever sufferers can expect from another La Niña season</a>
</strong>
</em>
</p>
<hr>
<h2>What is hay fever?</h2>
<p>In addition to genetic factors, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6436881">environmental exposures</a> such as airborne pollutants can dramatically predispose people to allergies.</p>
<p><strong>Common causes</strong></p>
<p>Causes of hay fever fall in three main groups:</p>
<ul>
<li><p>seasonal: pollens and plant materials that give symptoms at certain times of the year. Calendar charts of the various pollens are available</p></li>
<li><p>perennial/symptoms year round: however clean your house is, you will be exposed to fungal spores and to faeces from dust mites feeding off your dead skin cells. That sounds unsettling enough, but they can both be potent allergens that can’t be effectively avoided</p></li>
<li><p>intermittent: most typically these are animals’ dead skin. It’s worth noting the culprits are molecules in saliva, sweat and urine, not hair.</p></li>
</ul>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/pollen-does-more-than-make-you-sneeze-it-can-cause-thunderstorm-asthma-even-if-youre-not-asthmatic-190235">Pollen does more than make you sneeze. It can cause thunderstorm asthma, even if you're not asthmatic</a>
</strong>
</em>
</p>
<hr>
<h2>What treatments are best for hay fever?</h2>
<p>Given these serious consequences, it’s reassuring to know there are effective treatments for hay fever. These range from common over-the-counter products to specialist medicines. </p>
<p><strong>Antihistamines</strong></p>
<p>Many people will immediately think of antihistamines for hay fever: by tablet, nasal spray or eye drops. Histamine is a key messenger chemical in the allergy process, but it isn’t the only one. Therefore, antihistamines alone are usually usually only sufficient to get on top of mild problems.</p>
<p>There are a large number of antihistamines available with a range of effectiveness. Although many are available without prescription, bear in mind some are sedating, and some are unsafe in pregnancy, or when you have certain cardiac conditions, and may clash with some other medicines.</p>
<p><strong>Nasal treatments</strong></p>
<p>Nasal sprays apply treatment directly to microscopic hairs in the nose, helpfully spreading the medicine around. Many people take over-the-counter nasal corticosteroid spray to dampen down inflammation. </p>
<p>As a physician I’ve found it’s common in clinic for people to say sprays “don’t work” for them but usually this is because they don’t take them properly. These <a href="https://pubmed.ncbi.nlm.nih.gov/29050548/">treatments</a> can take many days to work, and need to be taken regularly every day. The trick is: don’t sniff them (the medicine will end up in the back of your throat), or spray them onto the sensitive middle part of the nose, which can bleed.</p>
<p>Saline sinus rinses can be very helpful in clearing mucus, allergens and inflammatory material (snot, to you and me) before using other medicines. <em>Always</em> use sterile liquids for this or nasty sinus infections can occur.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sneezing-with-hay-fever-native-plants-arent-usually-the-culprit-190336">Sneezing with hay fever? Native plants aren't usually the culprit</a>
</strong>
</em>
</p>
<hr>
<p><strong>Decongestants</strong></p>
<p>Decongestants might seem like a good idea when you can’t breathe, but are associated with a rebound worsening of swelling when they wear off (this has the excellent name of rhinitis medicamentosa). </p>
<p>As for many chemicals, if you take them long enough the body switches off its own supply (negative feedback) so when the drug is removed, the body is worse off. Think about how someone feels if they haven’t had a coffee all day and normally drinks four or five cups. There is a rebound of blood vessel dilation and mucus production. Use them sparingly.</p>
<figure class="align-center ">
<img alt="A person is standing outside using nasal spray. They wear glasses." src="https://images.theconversation.com/files/493735/original/file-20221107-23-zcbtt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/493735/original/file-20221107-23-zcbtt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/493735/original/file-20221107-23-zcbtt7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/493735/original/file-20221107-23-zcbtt7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/493735/original/file-20221107-23-zcbtt7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/493735/original/file-20221107-23-zcbtt7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/493735/original/file-20221107-23-zcbtt7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A lack of success of allergy treatments such as nasal sprays are often due to them not being used correctly.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-africanamerican-ethnicity-using-nasal-spray-2155318875">shutterstock</a></span>
</figcaption>
</figure>
<h2>Prescribed therapies</h2>
<p>If your hay fever is more severe, your doctor could consider a course of higher-strength nasal steroid drops, but these aren’t to be used for longer than a month as they can cause erosion of the nasal lining. </p>
<p>Adding a medicine that acts on other key messengers of inflammation (leukotrienes), such as montelukast, can sometimes be helpful. These tablets are usually well tolerated but can have side effects such as headache which lead to their discontinuation. </p>
<p>Validated scores that ask a standard set of questions about aspects of someone’s symptoms (such as “SNOT-22”) are helpful in assessing who needs extra prescription-based treatment for hay fever and their response to it.</p>
<h2>Specialist treatments</h2>
<p>For people with hay fever alongside asthma or other allergic disease, there are now effective medicines that block messengers of allergy in a highly specific manner, such as the <a href="https://pubmed.ncbi.nlm.nih.gov/29355679/">monoclonal antibody</a> Dupilumab, and more are <a href="https://erj.ersjournals.com/content/52/suppl_62/PA5248">coming soon</a>. Although too costly to be prescribed in hay fever alone, they show our understanding of the relevant mechanisms has improved.</p>
<p>Giving people a regular small dose of something they are sensitised to can make their immune system more tolerant of it. This is often referred to as immunotherapy, and can be by regular tablet or injection. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/im-considering-allergen-immunotherapy-for-my-hay-fever-what-do-i-need-to-know-190408">I’m considering allergen immunotherapy for my hay fever. What do I need to know?</a>
</strong>
</em>
</p>
<hr>
<p>Although <a href="https://www.thelancet.com/journals/lanepe/article/PIIS2666-7762(21)00261-1/fulltext">potentially very helpful</a>, this treatment takes years and many people <a href="https://www.ingentaconnect.com/content/ocean/aap/2021/00000042/00000001/art00015;jsessionid=18yqw4ncvah8.x-ic-live-01#">don’t complete their course</a>. The improvements seen are incremental rather than a complete <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6132438/">permanent resolution</a>.</p>
<hr>
<p><em>This article does not constitute specific medical advice. Please do speak to your GP, specialist or pharmacist about using the medicines mentioned here. You may also wish to review the helpful information and videos from <a href="https://asthma.org.au/about-asthma/triggers/hay-fever/">Asthma Australia</a></em></p><img src="https://counter.theconversation.com/content/194041/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Blakey and/or his employer has received funding for research or educational activities from companies that produce treatments for asthma, including Astra Zeneca, Boehringer Ingelheim, Chiesi, GSK, Novartis, Sanofi and Teva. He is affiliated with Asthma Australia and Asthma WA in a medical advisory capacity for which his organisation receives income. He is the WA branch president of the Thoracic Society of Australia and New Zealand. None of these entities had any input into or influence on this article.</span></em></p>Hay fever treatment options range from common over-the-counter products to specialist medicines.John D Blakey, Adjunct Clinical Associate Professor - Curtin Medical School, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1902352022-10-05T23:41:02Z2022-10-05T23:41:02ZPollen does more than make you sneeze. It can cause thunderstorm asthma, even if you’re not asthmatic<figure><img src="https://images.theconversation.com/files/488192/original/file-20221004-23-z8yzc0.jpg?ixlib=rb-1.1.0&rect=204%2C548%2C5259%2C3088&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-has-reflux-acids-park-551855089">Shutterstock</a></span></figcaption></figure><p>Climate change has caused melting icebergs, flooding, and landslides. It can also bring about an <a href="https://pubmed.ncbi.nlm.nih.gov/33228867/">increase</a> in pollen levels, prolong the duration of pollen season, and <a href="https://ehp.niehs.nih.gov/doi/10.1289/EHP173">cause more</a> pollen-related health problems.</p>
<p>Pollen grains landing on the moist membranes of the nose or eyes cause “hay fever” (allergic rhinitis) in <a href="https://www.aihw.gov.au/reports/chronic-respiratory-conditions/allergic-rhinitis-hay-fever/contents/allergic-rhinitis">one in five people</a>. This often leads to a runny or blocked nose and itchy eyes.</p>
<p>During the pollen season, people with asthma are at greater risk of a flare-up. </p>
<p>Pollen can also trigger <a href="https://pubmed.ncbi.nlm.nih.gov/31759647/">thunderstorm asthma</a>, even in those <a href="https://pubmed.ncbi.nlm.nih.gov/33996193/">who haven’t been diagnosed</a> with asthma and hay fever. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/lush-grasslands-higher-allergy-risks-what-hay-fever-sufferers-can-expect-from-another-la-nina-season-189982">Lush grasslands, higher allergy risks – what hay fever sufferers can expect from another La Niña season</a>
</strong>
</em>
</p>
<hr>
<h2>What is thunderstorm asthma?</h2>
<p>Thunderstorms <a href="https://pubmed.ncbi.nlm.nih.gov/29880157/">cause</a> a drop in temperature and a sudden rise in humidity. This <a href="https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(18)30120-7/fulltext">can cause</a> whole grass pollen grains to rupture into particles that are tiny enough to penetrate deeper into the lungs, which causes thunderstorm asthma. </p>
<p>Because of this, a lot of people – even those with no known asthma – can be affected. </p>
<p>The largest thunderstorm asthma event occurred in Melbourne during the 2016 grass pollen season – some <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/resp.13410">10,000 people</a> were affected and hospital emergency departments were over-capacity by <a href="https://pubmed.ncbi.nlm.nih.gov/29880157/">at least 3,000</a> respiratory-related cases. Sadly, ten people also died from asthma that night. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/TMQxBZ9M8g8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This short Better Health Channel video gives a quick overview of thunderstorm asthma.</span></figcaption>
</figure>
<h2>Who is at risk of thunderstorm asthma?</h2>
<p>Even people who do not have a history of asthma are at risk of thunderstorm asthma. However, research has shown some people can be more susceptible to pollen than others. This includes:</p>
<ul>
<li>those with <a href="https://pubmed.ncbi.nlm.nih.gov/29229087/">pollen allergy</a>, specifically <a href="https://pubmed.ncbi.nlm.nih.gov/34774618/">ryegrass pollen allergy</a></li>
<li>people who have respiratory conditions such as <a href="https://www.jacionline.org/article/S0091-6749(21)01689-4/fulltext">asthma</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/29229087/">hay fever</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/26048665/">a cold</a>, and <a href="https://www.safercare.vic.gov.au/clinical-guidance/covid-19/epidemic-thunderstorm-asthma">COVID</a></li>
<li>being outdoors at <a href="https://pubmed.ncbi.nlm.nih.gov/29229087/">the time of the thunderstorm</a></li>
<li>people who are <a href="https://pubmed.ncbi.nlm.nih.gov/29573176/">of Asian ethnicity</a></li>
<li>people living in areas with <a href="https://pubmed.ncbi.nlm.nih.gov/33131877/">lots of plant life</a></li>
<li>children with <a href="https://pubmed.ncbi.nlm.nih.gov/35398553/">a food allergy or eczema</a></li>
<li>those with exposure to high levels of <a href="https://pubmed.ncbi.nlm.nih.gov/34116012/">air pollution</a></li>
<li>those with lower <a href="https://pubmed.ncbi.nlm.nih.gov/15723767/">socioeconomic status</a>, as reduced access to health care and poor quality housing can exacerbate symptoms. </li>
</ul>
<p>In our research, we found people with <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/all.14566">co-existing allergic conditions</a> (such as asthma and hay fever) to be more impacted by pollen compared to those with single allergic conditions (such as asthma only). </p>
<h2>How else can pollen cause harm?</h2>
<p>Even outside of thunderstorms, pollen alone can <a href="https://www.mdpi.com/1660-4601/19/12/7541">cause</a> asthma attacks requiring hospitalisations, respiratory symptoms such as wheezing and runny nose, and reduced lung function, making it harder to breath.</p>
<p>Despite a low mortality rate, allergic asthma and hay fever can cause further <a href="https://pubmed.ncbi.nlm.nih.gov/15698810/">burdens</a> such as additional <a href="https://erj.ersjournals.com/content/21/1/116">health-care costs</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/11029350/">poorer physical and mental health</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1577143799859535874"}"></div></p>
<p>Our yet-to-be-published research has shown grass pollen may trigger a general state of heightened immune responses, leading to increased risk of eczema flares in children. </p>
<p>Other <a href="https://www.sciencedirect.com/science/article/pii/S0022202X15321904">studies</a> have indicated children with eczema experience more symptoms such as a higher intensity of itchiness and rash on days with high levels of grass pollen.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sneezing-with-hay-fever-native-plants-arent-usually-the-culprit-190336">Sneezing with hay fever? Native plants aren't usually the culprit</a>
</strong>
</em>
</p>
<hr>
<h2>How can you prepare?</h2>
<p>So, what can you do to prepare for the grass pollen season and the threat of thunderstorm asthma?</p>
<ul>
<li>download your state’s emergency services app, such as the Victorian Emergency App, which can provide thunderstorm asthma alerts</li>
<li>keep an eye on pollen counts (see below for useful websites)</li>
<li>keep doors and windows closed on high pollen days</li>
<li>use air purifiers<br></li>
<li>stay indoors during high pollen counts or thunderstorm asthma alerts</li>
<li>plant non-allergenic flowers if you have a garden</li>
<li>keep wearing a face mask. <a href="https://pubmed.ncbi.nlm.nih.gov/34277327/">Masks</a> have shown to be very effective in reducing the risk of COVID-19 infection and pollen-induced respiratory symptoms</li>
<li>take anti-asthma medications. Reliever medications are available over-the-counter. Preventer medications offer much stronger protection but require a prescription from a doctor. They also need to be used preventatively in the setting of pollen-induced asthma, or in severe hay fever, to prevent thunderstorm asthma </li>
<li>take antihistamines such as Zyrtec, which can be used both on an as-needed basis or more regularly through the pollen season. However, it does not treat or prevent asthma. </li>
</ul>
<figure class="align-center ">
<img alt="Person uses an asthma inhaler" src="https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">People with diagnosed asthma should take their preventer medication regularly during the pollen season.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/health-medicine-young-girl-using-blue-1503422258">Shutterstock</a></span>
</figcaption>
</figure>
<p>If you know you suffer from asthma, hay fever or pollen allergy, you are at risk of thunderstorm asthma. Aside from taking advantage of warning systems and staying out of the storm, you should see your doctor and have an asthma puffer at hand through the pollen season to keep yourself safe. Your doctor can advise you on the correct treatment. </p>
<p>Research including our own has shown pollen exposure can have a <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/all.14566">lagged effect</a> on the lungs and airways. This means asthma attacks or respiratory symptoms can sometimes occur a few days after exposure. So, if you forget to take medications pre-emptively, it’s not too late. However, go to a hospital if it gets severe. </p>
<p>Refer to the following websites for useful daily pollen information in Australia: <a href="https://airrater.org/">AirRater</a> or <a href="https://www.pollenforecast.com.au/">AusPollen</a>.</p><img src="https://counter.theconversation.com/content/190235/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shyamali Dharmage receives funding from the Australian National Health and Medical Research Council (NHMRC). She currently holds investigator-initiated grants from GSK and AstraZeneca for unrelated work. </span></em></p><p class="fine-print"><em><span>Jo Douglass has received honoraria for educational presentations from Astra-Zeneca, GSK, Novartis, Shire, & CSL. She has served on advisory boards: Sanofi-Aventis, Novartis, GSK, Astra-Zeneca, Shire, Immunosis, Equilium and CSL. She has undertaken contracted or investigator-initiated research for unrelated work on behalf of: GSK, Novartis, Immunosis, AstraZeneca, Sanofi-Aventis, Grifols, CSL, BioCryst & Equilium. She has a personal superannuation shareholding in CSL.</span></em></p><p class="fine-print"><em><span>Sabrina Idrose receives funding from the NHMRC Centre for Food and Allergy Research and LifeCourse PhD scholarships.</span></em></p>Pollen can trigger thunderstorm asthma, even in those without diagnosed asthma.Shyamali Dharmage, NHMRC Professorial Fellow, The University of MelbourneJo Douglass, Professor of Medicine, The University of MelbourneSabrina Idrose, PhD Candidate, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1904082022-10-04T02:52:19Z2022-10-04T02:52:19ZI’m considering allergen immunotherapy for my hay fever. What do I need to know?<figure><img src="https://images.theconversation.com/files/487201/original/file-20220929-16-46ny3y.jpg?ixlib=rb-1.1.0&rect=138%2C467%2C5633%2C3375&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/coronavirus-covid19-concept-unhealthy-asian-woman-1686256522">Shutterstock</a></span></figcaption></figure><p>Allergic rhinitis, commonly referred to as hay fever, is a common allergic disorder affecting up to <a href="https://www.aihw.gov.au/reports/chronic-respiratory-conditions/allergic-rhinitis-hay-fever/report-editions">one in five Australians</a>. Symptoms include itchy nose and eyes, excessive sneezing or clear nasal discharge and nasal congestion. </p>
<p>When severe or untreated, hay fever can affect your <a href="https://pubmed.ncbi.nlm.nih.gov/31466686/">quality of life</a>, resulting in poor sleep, impaired learning, and difficulty in concentrating at school or work. </p>
<p>People with hay fever usually use over-the-counter antihistamines as required. For recurrent or frequent symptoms, corticosteroid nasal sprays are preventive medications readily available over the counter, and are most effective when used regularly. </p>
<p>However, if you continue to have <a href="https://pubmed.ncbi.nlm.nih.gov/30955224/">severe and troubling symptoms</a>, you might be considering <a href="https://www.allergy.org.au/allergic-rhinitis">allergen immunotherapy</a>, also known as allergen desensitisation. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/lush-grasslands-higher-allergy-risks-what-hay-fever-sufferers-can-expect-from-another-la-nina-season-189982">Lush grasslands, higher allergy risks – what hay fever sufferers can expect from another La Niña season</a>
</strong>
</em>
</p>
<hr>
<h2>Remind me, what happens when you get hay fever?</h2>
<p>Hay fever triggers an <a href="https://link.springer.com/chapter/10.1007/978-3-030-21217-9_32">exaggerated immune response</a> to otherwise harmless airborne allergens such as grass pollen, house dust mite or animal dander. These can end up on the lining of the nose and eyes, which causes irritation. </p>
<p>When encountering these allergens as foreign molecules, the immune system generates proteins, called antibodies. These antibodies are able to accurately recognise that particular molecule as foreign.</p>
<p>In people with hay fever, a <a href="https://pubmed.ncbi.nlm.nih.gov/33273461/">particular type of antibody</a>, called IgE, is generated. These allergen-specific IgE antibodies then “prime” or prepare cells in the lining of the nose and eyes to recognise and trigger allergic responses when exposed to these allergens. </p>
<p>When the “primed” cells contact the allergen, they release stored molecules, such as histamine. Histamine acts on neighbouring cells to trigger symptoms such as itch, sneeze and runny nose. </p>
<p>Over time, the ongoing stimulation by the allergen will trigger a <a href="https://pubmed.ncbi.nlm.nih.gov/31015846">chronic response</a>. This leads to nasal congestion and tissue swelling of the nasal, or eye lining.</p>
<figure class="align-center ">
<img alt="Man uses nasal spray" src="https://images.theconversation.com/files/487218/original/file-20220929-22-8v0emj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/487218/original/file-20220929-22-8v0emj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/487218/original/file-20220929-22-8v0emj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/487218/original/file-20220929-22-8v0emj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/487218/original/file-20220929-22-8v0emj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/487218/original/file-20220929-22-8v0emj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/487218/original/file-20220929-22-8v0emj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">For some people, nasal sprays don’t provide enough relief.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/senior-man-using-nasal-spray-close-1411533125">Shutterstock</a></span>
</figcaption>
</figure>
<h2>How does allergen immunotherapy work?</h2>
<p>The first step is to ask your GP for a referral to an allergist or clinical immunologist to discuss the best treatment for you.</p>
<p>Your allergist or clinical immunologist will begin by identifying your triggers. This can be done through skin prick tests when you visit the allergy clinic, or through blood tests that detect and measure the proteins (antibodies) that underpin the allergic response. </p>
<p>Allergen immunotherapy <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3395833/">dampens</a> the exaggerated response to a specific allergen. It does this by developing cells and antibodies that block rather than activate the immune response against a particular allergen. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sneezing-with-hay-fever-native-plants-arent-usually-the-culprit-190336">Sneezing with hay fever? Native plants aren't usually the culprit</a>
</strong>
</em>
</p>
<hr>
<h2>How is it administered?</h2>
<p>Allergen immunotherapy is administered by either injections under the skin (subcutaneous) or drops, tablets or wafers placed under the tongue (sublingual). </p>
<p>The treatment is started by an allergist in the clinic. Injection allergen immunotherapy may then be administered regularly by your GP, usually monthly, while sublingual allergen immunotherapy is taken daily at home. </p>
<p>Patients commonly ask which treatment is better. Research indicates <a href="https://pubmed.ncbi.nlm.nih.gov/28940458/">both</a> are effective strategies to minimise the allergic symptoms. For an individual, the choice should depend on a number of patient factors such as asthma, expected tolerability, and, importantly, time constraints (for example, the time it takes to see a GP).</p>
<p>While allergen immunotherapy for children can start as young as <a href="https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/allergic-rhinitis-or-hay-fever">five years of age</a>, parents should discuss the best treatment for their child with the allergist. Some children may not tolerate regular injections, while others are unable to hold the tablet under the tongue.</p>
<h2>How much does it cost?</h2>
<p>The cost vary depending on product as allergen immunotherapy products are not subsidised under the PBS. </p>
<p>The sublingual allergen immunotherapy products costs about A$120-$150 per month.</p>
<p>The injection costs about A$600-1200 per year (approximately A$50-100 per month). </p>
<h2>How long does it take to work?</h2>
<p>The allergist will determine the best time to start allergen immunotherapy, as some products would be preferable to start before spring (for example, grass pollen immunotherapy). </p>
<p>Effective allergen immunotherapy should minimise the allergic symptoms after re-exposure to the allergen. However, this immune “reset” does not have an immediate effect. Patients on allergen immunotherapy typically only notice improved symptoms after six to 12 months. </p>
<figure class="align-center ">
<img alt="Person with red eyes" src="https://images.theconversation.com/files/487200/original/file-20220929-15-ug55ua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/487200/original/file-20220929-15-ug55ua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/487200/original/file-20220929-15-ug55ua.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/487200/original/file-20220929-15-ug55ua.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/487200/original/file-20220929-15-ug55ua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/487200/original/file-20220929-15-ug55ua.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/487200/original/file-20220929-15-ug55ua.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hay fever is an allergic response causing symptoms such as itchy eyes.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/oPWGhqBPNI0">Erik Mclean</a></span>
</figcaption>
</figure>
<p>Patients who undergo treatment should expect symptom improvement within the first year, although there may be continued gradual improvements over future years of treatment. </p>
<p>Allergen immunotherapy may also help <a href="https://pubmed.ncbi.nlm.nih.gov/20687065/">reduces asthma flare ups</a> in people diagnosed with the condition who also get hay fever. It’s particularly effective in <a href="https://pubmed.ncbi.nlm.nih.gov/29461859/">preventing asthma flares driven by turbulent weather storms</a>, also known as <a href="https://www.allergy.org.au/patients/asthma-and-allergy/thunderstorm-asthma">thunderstorm asthma</a>. </p>
<p>Allergen immunotherapy may also decrease the chance of children with hay fever developing <a href="https://pubmed.ncbi.nlm.nih.gov/28689794/">asthma</a>.</p>
<h2>What are the side effects?</h2>
<p>Allergen immunotherapy through sublingual or injections may typically cause local allergic symptoms such as itch, tingling tongue/mouth or localised redness or pain at the injection site. </p>
<p>Significant side effects from both allergen immunotherapy routes are <a href="https://pubmed.ncbi.nlm.nih.gov/30955224/">very rare</a>, and can include a severe allergic reaction, particularly if you have asthma. Patients with asthma should only start allergen immunotherapy if and when their asthma is well-controlled. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/do-i-have-covid-or-hay-fever-heres-how-to-tell-188030">Do I have COVID or hay fever? Here’s how to tell</a>
</strong>
</em>
</p>
<hr>
<h2>How long do improvements last?</h2>
<p>For effective allergen immunotherapy, patients should receive gradual and regular administration of the trigger allergen(s) for at <a href="https://pubmed.ncbi.nlm.nih.gov/30221122/">least three years</a>. </p>
<p>The clinical benefits from allergen immunotherapy are not indefinite, but allergen immunotherapy administered regularly over three to five years will help prolong the <a href="https://pubmed.ncbi.nlm.nih.gov/30221122/">sustained response</a> over at least two to three years after stopping.</p>
<p>During this period, patients should have at least yearly reviews with their specialist to ensure the treatment is working and there are no issues with side effects.</p><img src="https://counter.theconversation.com/content/190408/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>It’s a long-term treatment – people having allergen immunotherapy typically notice improved symptoms after six to 12 months.Paxton Loke, Paediatric Allergist and Immunologist, Murdoch Children's Research InstituteJulian Bosco, Clinical immunologist and allergist, department of respiratory medicine at The Alfred; adjunct senior lecturer, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1899822022-09-14T00:33:26Z2022-09-14T00:33:26ZLush grasslands, higher allergy risks – what hay fever sufferers can expect from another La Niña season<figure><img src="https://images.theconversation.com/files/484227/original/file-20220913-22-djkxnd.jpg?ixlib=rb-1.1.0&rect=26%2C26%2C4427%2C2544&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://images.pexels.com/photos/129539/pexels-photo-129539.jpeg?auto=compress&cs=tinysrgb&w=1260&h=750&dpr=2">Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Australia has among the highest prevalence of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3353191/">asthma</a> and <a href="https://www.phrp.com.au/issues/december-2018-volume-28-issue-4/climate-change-and-allergy-in-australia-an-innovative-high-income-country-at-potential-risk/">hay fever</a> globally. La Niña (and El Niño) will undoubtedly affect allergy sufferers. </p>
<p>Sea-surface temperatures across the east-central equatorial Pacific <a href="https://www.nature.com/articles/s43017-021-00199-z">cycle between episodes</a> of La Niña (when the sea is cooler) and El Niño (when it is warmer). These complex weather patterns are likely to alter the amount of pollen in the air. </p>
<p>A La Niña event has been <a href="https://www.abc.net.au/news/2022-09-13/bom-declares-third-la-nina-summer-weather-flood-risk/101424100">declared</a> for the third year in a row, increasing the likelihood eastern and northern Australia will be wetter than normal. This will raise health concerns for some people due to prolific pastureland growth and more grass pollen. </p>
<p>Allergic rhinitis (hay fever) and asthma can be <a href="https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/pollen-allergy">triggered</a> by pollen from grasses, weeds or trees. Thunderstorms can also be a trigger.</p>
<p>Record rainfalls in regional Victoria led up to Australia’s most catastrophic respiratory allergy event in November 2016, when <a href="https://www.thelancet.com/pdfs/journals/lanplh/PIIS2542-5196(18)30120-7.pdf">thunderstorm asthma</a> was linked to several thousand trips to Melbourne hospital emergency departments and ten deaths. </p>
<p>But our understanding of how climate change is affecting risk is limited by sparse and intermittent <a href="https://doi.org/10.1016/j.envres.2022.113762">pollen monitoring in Australia</a>. We’ll need continuous pollen records for at least ten or 20 years to track the effects on pollen exposure.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-climate-scientist-on-the-planets-simultaneous-disasters-from-pakistans-horror-floods-to-europes-record-drought-189626">A climate scientist on the planet's simultaneous disasters, from Pakistan’s horror floods to Europe’s record drought</a>
</strong>
</em>
</p>
<hr>
<h2>Climate change and what to expect</h2>
<p>Climate change appears to increase our exposure to airborne allergens such as grass pollen. <a href="https://doi.org/10.3389/falgy.2021.705313">Research</a> recently showed the amount of Brisbane grass pollen measured from 2016 to 2020 was almost triple the amount monitored between 1994 and 1999. </p>
<p>This was linked with increasing carbon dioxide in the atmosphere, increasing temperature and lusher vegetation. The number and proportion of days with grass pollen at high and extreme levels increased significantly over time, bringing more health risks. </p>
<p>Highly elevated grass pollen levels were also seen during <a href="https://auspollen.edu.au/brisbane/">the 2021 grass pollen season</a> up until flooding in February 2022. </p>
<p>It’s early days, but given the <a href="http://www.bom.gov.au/climate/enso/">declaration of another La Niña season</a>, the upcoming grass pollen season will likely to be high again this spring and summer at least in some parts of Australia.</p>
<p>Pollen exposure differs significantly <a href="https://link.springer.com/article/10.1007/s10453-015-9399-x">between locations and years</a>. So understanding local environmental drivers is important. </p>
<p>Using over 20 years of <a href="https://www.nature.com/articles/s43017-022-00298-5">satellite data</a> and ground-based cameras to monitor the life cycle of grasses (including peak growth periods, flowering and pollination) we’ve shown climate change is <a href="https://doi.org/10.1016/j.rse.2022.112983">altering the composition of grasslands</a> with warm season grasses steadily increasing. Changes in the types of grasses growing alter allergen composition, severity, and the seasonal timing of pollen exposure. This is important for <a href="https://onlinelibrary.wiley.com/doi/10.1002/cti2.1103">sensitisation, diagnosis and management</a> of people with hay fever.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="pollen in the air" src="https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Longer seasons for warm season grasses can exacerbate allergic conditions.</span>
<span class="attribution"><a class="source" href="https://image.shutterstock.com/image-photo/dust-pollen-small-particles-fly-600w-1386898265.jpg">Shutterstock</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/do-i-have-covid-or-hay-fever-heres-how-to-tell-188030">Do I have COVID or hay fever? Here’s how to tell</a>
</strong>
</em>
</p>
<hr>
<h2>Keeping track of pollen</h2>
<p>Currently, pollen monitoring is mostly undertaken by academic research groups dependent on short-term competitive funding. </p>
<p>Australia is several years behind Europe and Japan in adopting <a href="https://doi.org/10.1002/clt2.12015">automated, real-time pollen monitoring</a>. Our current manual pollen monitoring processes are labour intensive and <a href="https://link.springer.com/article/10.1007/s10453-020-09656-6">imprecise</a>. </p>
<p>For Australia to set up similar monitoring, instruments would need to learn to detect, match and count local pollens and be capable of operating over time in our diverse and often harsh external environments. </p>
<p>Access to real-time automated pollen monitoring across a broad coverage of sites would help with pollen forecasting. This could inform both short-term daily pollen forecasts, and early pollen season warnings. </p>
<p>While there are approximately <a href="https://auspollen.edu.au/auspollensitesmap/">25 active pollen monitoring sites in Australia</a>, these are mostly located in urban areas, and across Victoria. We need a wider network of monitoring sites to serve community needs and to foster better understanding of <a href="https://gmd.copernicus.org/articles/12/2195/2019/">pollen sources</a> and health implications.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1569482147794415616"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/no-not-again-a-third-straight-la-nina-is-likely-heres-how-you-and-your-family-can-prepare-188970">No, not again! A third straight La Niña is likely – here’s how you and your family can prepare</a>
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</p>
<hr>
<h2>A national approach to allergies</h2>
<p>The freshly launched <a href="https://www.allergy.org.au/about-ascia/info-updates/launch-of-national-allergy-council-and-national-allergy-centre-of-excellence">National Allergy Centre for Excellence</a> will hopefully push for all Australians with pollen allergies to have access to accurate pollen information. </p>
<p>For now, those with allergies should keep an eye on the <a href="https://asthma.org.au/pollen-monitoring/">currently available</a> pollen counts. If you need <a href="https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/pollen-allergy">advice on how to better manage your pollen allergies</a>, especially if you are at risk of <a href="https://www.sciencedirect.com/science/article/pii/S0091674921016894?via%3Dihub">seasonal allergic asthma</a>, consult your pharmacist or discuss treatment options with your doctor. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1569504210684903424"}"></div></p><img src="https://counter.theconversation.com/content/189982/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janet Davies has received funding in the last five years from National Health and Medical Research Council (GNT1116107), Australian Research Council (DP210100347, LP190100216, DP190100376, DP170101630), National Foundation of Medical Research Innovation with co-funding from Abionic Switzerland. QUT owns patents granted for allergy diagnostics.</span></em></p><p class="fine-print"><em><span>Alfredo Huete receives funding from the Australian Research Council (DP210100347, DP170101630), the Terrestrial Ecosystem Research Network (TERN), the National Health and Medical Research Council (GNT1116107), and Climate-KIC Australia Fairwater Living Lab.</span></em></p><p class="fine-print"><em><span>Paul Beggs does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A third La Niña event in a row could bring dangerous conditions for people with allergies – but we’ll need better continuous monitoring to be sure what’s coming in the future.Janet Davies, Professor, Queensland University of TechnologyAlfredo Huete, Professor, Climate Change Cluster, University of Technology SydneyPaul Beggs, Associate Professor and Environmental Health Scientist, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1903362022-09-12T20:27:42Z2022-09-12T20:27:42ZSneezing with hay fever? Native plants aren’t usually the culprit<figure><img src="https://images.theconversation.com/files/483626/original/file-20220908-12-h4xyg8.jpg?ixlib=rb-1.1.0&rect=204%2C57%2C5259%2C3579&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/allergy-concept-young-asian-woman-sneezes-1163542810">shutterstock</a></span></figcaption></figure><p>Hay fever is a downside of springtime around the world. As temperatures increase, plant growth resumes and flowers start appearing. </p>
<p>But while native flowering plants such as wattle often get the blame when the seasonal sneezes strike, hay fever in Australia is typically caused by introduced plant species often pollinated by the wind.</p>
<h2>A closer look at pollen</h2>
<p>Pollen grains are the tiny reproductive structures that move genetic material between flower parts, individual flowers on the same plant or a nearby member of the same species. They are typically lightweight structures easily carried on wind currents or are sticky and picked up in clumps on the feathers of a honeyeater or the fur of a fruit bat or possum. </p>
<p>Hay fever is when the human immune system overreacts to allergens in the air. It is not only caused by pollen grains but fungal spores, non-flowering plant spores, mites and even pet hair. </p>
<p>The classic symptoms of hay fever are sneezing, runny noses, red, itchy, and watery eyes, swelling around the eyes and scratchy ears and throat. </p>
<p>The problem with pollen grains is when they land on the skin around our eyes, in our nose and mouth, the proteins found in the wall of these tiny structures leak out and are recognised as foreign by the body and trigger a reaction from the immune system.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/do-i-have-covid-or-hay-fever-heres-how-to-tell-188030">Do I have COVID or hay fever? Here’s how to tell</a>
</strong>
</em>
</p>
<hr>
<h2>So what plants are the worst culprits for causing hay fever?</h2>
<p>Grasses, trees, and herbaceous weeds such as plantain are the main problem species as their pollen is usually scattered by wind. In Australia, the main grass offenders are exotic species including rye grass and couch grass (a commonly used lawn species). </p>
<p>Weed species that cause hay fever problems include introduced ragweed, Paterson’s curse, parthenium weed and plantain. The <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5102629/">problematic tree species</a> are also exotic in origin and include liquid amber, Chinese elm, maple, cypress, ash, birch, poplar, and plane trees.</p>
<p>Although there are some native plants that have wind-spread pollen such as she-oaks and white cypress pine, and which can induce hay fever, these species are exceptional in the Australian flora. Many Australian plants are not wind pollinated and <a href="https://blog.publish.csiro.au/austpollinatorweek/">use animals</a> to move their clumped pollen around.</p>
<p>For example, yellow-coloured flowers such as wattles and peas are pollinated by insect such as bees. Red- and orange-coloured flowers are usually visited by birds such as honeyeaters. Large, dull-coloured flowers with copious nectar (the reward for pollination) are visited by nocturnal mammals including bats and possums. Obviously Australian plant pollen can still potentially cause the immune system to overreact, but these structures are less likely to reach the mucous membranes of humans.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/got-allergies-you-could-be-at-lower-risk-of-catching-covid-188486">Got allergies? You could be at lower risk of catching COVID</a>
</strong>
</em>
</p>
<hr>
<h2>What can we do to prevent hay fever attacks at this time of the year?</h2>
<p>With all of this in mind, here are some strategies to prevent the affects of hay fever:</p>
<ol>
<li>stay inside and keep the house closed up on warm, windy days when more pollen is in the air </li>
<li>if you must go outside, wear sunglasses and a face mask</li>
<li>when you return indoors gently rinse (and don’t rub) your eyes with running water, change your clothes and shower to remove pollen grains from hair and skin </li>
<li>try to avoid mowing the lawn in spring particularly when grasses are in flower (the multi-pronged spiked flowers of couch grass are distinctive)</li>
<li>when working in the garden, wear gloves and facial coverings particularly when handling flowers </li>
<li>consider converting your garden to a native one. Grevilleas are a great alternative to rose bushes. Coastal rosemary are a fabulous native replacement for lavender. Why not replace your liquid amber tree with a fast growing, evergreen and low-allergenic lilly pilly tree?</li>
</ol>
<h2>If you do suffer a hay fever attack</h2>
<p>Sometimes even with our best efforts, or if it’s not always possible to stay at home, hay fever can still creep up on us. If this happens:</p>
<ul>
<li>antihistamines will reduce sneezing and itching symptoms</li>
<li>corticosteroid nasal sprays are very effective at reducing inflammation and clearing blocked noses</li>
<li>decongestants provide quick and temporary relief by drying runny noses but should not be used by those with high blood pressure </li>
<li>salt water is a good way to remove excessive mucous from the nasal passages.</li>
</ul>
<p>Behavioural changes on warm, windy spring days are a good way of avoiding a hay fever attack. </p>
<p>An awareness of the plants around us and their basic reproductive biology is also useful in preventing our immune systems from overreacting to pollen proteins that they are not used to encountering.</p><img src="https://counter.theconversation.com/content/190336/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Dearnaley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>With spring’s arrival, it’s important to know which plants might exacerbate hay fever. Surprisingly, it’s not native wattles you have to watch out for.John Dearnaley, Associate Professor, University of Southern QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1884862022-08-24T15:21:32Z2022-08-24T15:21:32ZGot allergies? You could be at lower risk of catching COVID<figure><img src="https://images.theconversation.com/files/480780/original/file-20220824-20-sdo0s6.jpg?ixlib=rb-1.1.0&rect=41%2C0%2C4611%2C3071&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/allergy-mosquito-bite-man-scratcing-arm-2006427659">aleks333/Shutterstock</a></span></figcaption></figure><p>To respond effectively to COVID, it’s been important to understand who may be at higher risk of contracting the virus and developing more severe disease.</p>
<p>To this end, scientists and clinicians have established a range of <a href="https://thorax.bmj.com/content/77/9/900">risk factors</a> for serious illness with COVID, including older age, obesity, and several underlying health conditions. High body mass index also appears to be linked with increased odds of catching COVID in the first place. </p>
<p>But what about factors that might make someone less likely to contract COVID? Interestingly, <a href="https://thorax.bmj.com/content/77/9/900">research suggests</a> that <a href="https://www.jacionline.org/article/S0091-6749(22)00752-7/fulltext">having allergies</a> could reduce a person’s risk.</p>
<p>Allergies are very common. At least <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4045871/">400 million people</a> around the world are affected by pollen allergies, or hay fever. Some 300 million people suffer from allergic asthma (induced by inhaling allergens), while food allergies affect around 250 million. Many people are also allergic to certain drugs. Allergic reactions can range from mild (perhaps some redness and swelling on the skin) to severe (anaphylactic shock, which can cause death). </p>
<p>Atopic diseases is a name given to a group of conditions triggered by allergens and includes hay fever, eczema and dermatitis. Research has shown that people with atopic diseases have <a href="https://thorax.bmj.com/content/early/2021/11/02/thoraxjnl-2021-217487">25% lower odds</a> of contracting COVID. For people with atopic disease and asthma, the risk is <a href="https://thorax.bmj.com/content/early/2021/11/02/thoraxjnl-2021-217487">38% lower</a> compared to people without these conditions. </p>
<p>A separate study showed that people with food allergies were <a href="https://www.jacionline.org/article/S0091-6749(22)00752-7/fulltext">50% less likely</a> to become infected with COVID.</p>
<h2>Why would people with allergies be at lower risk?</h2>
<p>Initially we thought that people with allergies could be less likely to contract COVID as they may have been more isolated from others. This might be true for asthma because people with this condition were advised <a href="https://www.gov.uk/government/publications/guidance-on-shielding-and-protecting-extremely-vulnerable-persons-from-covid-19/guidance-on-shielding-and-protecting-extremely-vulnerable-persons-from-covid-19">to shield</a> earlier in the pandemic. </p>
<p>But the same can’t be said for the majority of atopic diseases, such as eczema. And while you might expect people with food allergies to, say, eat out less, research during the pandemic has shown that households with food allergies only had slightly lower levels <a href="https://www.jacionline.org/article/S0091-6749(22)00752-7/fulltext">of exposure</a> in the community compared with other households.</p>
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Read more:
<a href="https://theconversation.com/do-i-have-covid-or-hay-fever-heres-how-to-tell-188030">Do I have COVID or hay fever? Here’s how to tell</a>
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<p>To be able to infect the body, SARS-CoV-2 (the virus that causes COVID-19) attaches to a specific protein called <a href="https://theconversation.com/what-is-the-ace2-receptor-how-is-it-connected-to-coronavirus-and-why-might-it-be-key-to-treating-covid-19-the-experts-explain-136928">the ACE2 receptor</a>. This protein provides the entry point for the virus to infect a wide range of human cells. </p>
<p>Having higher amounts of ACE2 receptors is associated with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1287568/">increased susceptibility</a> to COVID infection. People who smoke, have diabetes or high blood pressure (all of which are associated with a higher likelihood of <a href="https://www.jacionline.org/article/S0091-6749(20)30551-0/fulltext">severe COVID</a>) have more ACE2 receptors.</p>
<p>Meanwhile, it has been shown that type 2 inflammation – a normal immune reaction that can occur in response to infections or parasites, but also occurs prominently in allergic conditions – <a href="https://www.jacionline.org/article/S0091-6749(20)30551-0/fulltext">reduces ACE2 expression</a> in the airways. This decreases susceptibility to infection, and is considered the primary reason people with allergies appear to be at lower risk of catching COVID.</p>
<p>There are also a range of other factors that may contribute to reducing COVID infection risk among those with allergies. For example, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7651838/">people with asthma</a> tend to produce more mucus than others, which is understood to prevent SARS-CoV-2 entering the airways.</p>
<figure class="align-center ">
<img alt="A bowl of peanuts." src="https://images.theconversation.com/files/480782/original/file-20220824-18-9q4zfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480782/original/file-20220824-18-9q4zfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480782/original/file-20220824-18-9q4zfs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480782/original/file-20220824-18-9q4zfs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480782/original/file-20220824-18-9q4zfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480782/original/file-20220824-18-9q4zfs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480782/original/file-20220824-18-9q4zfs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Many millions of people suffer from food allergies.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/baked-peanuts-put-cup-placed-on-1500474608">kram-9/Shutterstock</a></span>
</figcaption>
</figure>
<h2>More good news</h2>
<p>So we see a reduced risk of catching COVID in people with allergies and asthma. But how do these conditions affect the severity of a COVID infection? </p>
<p>At the beginning of the pandemic, it was assumed that people with asthma may be at greater risk of getting very sick from COVID, because viral infections <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6820381/">commonly exacerbate asthma</a>. But it’s now well established that asthma that’s <a href="https://thorax.bmj.com/content/early/2022/03/29/thoraxjnl-2021-218629">mild or well controlled</a> doesn’t increase the risk of serious illness with COVID. And the evidence doesn’t indicate more <a href="https://www.aaaai.org/Tools-for-the-Public/Conditions-Library/Asthma/covid-prevent">severe asthma</a> increases the risk either.</p>
<p>Similarly, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7820556/">atopic disease</a> is not considered a risk factor for severe COVID.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-psychologists-can-help-people-coping-with-life-threatening-food-allergies-127933">How psychologists can help people coping with life threatening food allergies</a>
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</em>
</p>
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<p>If you suffer with other diseases in combination with asthma or allergies, it’s important to be aware that this could <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8689956/">increase COVID severity</a>. </p>
<p>Prevention remains key. The best ways to prevent <a href="https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public">COVID infection</a> continue to include vaccination, wearing appropriately-fitting face coverings, and physical distancing. </p>
<p>Meanwhile, if you have allergies, having an allergy management plan is essential. Make sure your treatment plan is current and that you have medications on hand in case you need them.</p><img src="https://counter.theconversation.com/content/188486/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Philippe B. Wilson is Chief Scientific Officer of NHS Willows Health. </span></em></p><p class="fine-print"><em><span>Samuel J. White does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Evidence has shown that people with allergies and asthma are at lower risk of contracting COVID-19. Here’s why we think this might be.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1880302022-08-05T11:44:56Z2022-08-05T11:44:56ZDo I have COVID or hay fever? Here’s how to tell<figure><img src="https://images.theconversation.com/files/477411/original/file-20220803-14-u61x1y.jpg?ixlib=rb-1.1.0&rect=44%2C0%2C5000%2C3330&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-woman-blowing-her-nose-while-236652919">ShutterDivision/Shutterstock</a></span></figcaption></figure><p>With warm weather in the northern hemisphere, many people will be suffering from pollen allergies. Also called <a href="https://www.nhs.uk/conditions/hay-fever/">hay fever</a>, this common condition affects millions of people around the world during the spring, summer and autumn months.</p>
<p>Meanwhile, COVID cases are high. Although seasonal allergies are commonplace for many people, there’s significant overlap between COVID and hay fever symptoms. This could lead people to mistake COVID for allergies, in turn exacerbating the spread of COVID in the community.</p>
<p>Notably, we’re now often seeing <a href="https://www.bmj.com/content/373/bmj.n1088.full">milder COVID symptoms</a> compared with earlier in the pandemic. This is due to a combination of factors including increased immunity from vaccines and prior infections, and the evolution of new variants of the virus.</p>
<p>Of course, it’s a good thing that people generally aren’t getting as sick with COVID. At the same time, this could actually increase confusion between COVID and other illnesses or allergies. </p>
<p>The latest data from the UK’s <a href="https://www.youtube.com/watch?v=05_idwi66jM&t=547s">ZOE app</a>, which tracks people’s self-reported COVID symptoms, shows the most commonly reported symptoms of COVID are now a sore throat, followed by headache, cough, blocked nose and runny nose. These symptoms can all affect people with pollen allergies. So it’s very possible someone might dismiss COVID as the onset of their usual allergies.</p>
<h2>COVID symptoms vs hay fever symptoms</h2>
<iframe title="" aria-label="Table" id="datawrapper-chart-q44G6" src="https://datawrapper.dwcdn.net/q44G6/1/" scrolling="no" frameborder="0" style="border: none;" width="100%" height="512"></iframe>
<p>Although there are several overlapping symptoms, there are a few key symptoms that may help you distinguish between COVID and hay fever.</p>
<p><strong>Itchy eyes:</strong> Itchy, red, watery or puffy eyes are a common sign of pollen allergies, but are not associated with COVID.</p>
<p><strong>Fever or chills:</strong> A high temperature is not a sign of pollen allergies, but it’s a fairly common COVID symptom. So if you have a fever, in combination with other symptoms, you may have COVID or another respiratory infection. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/how-do-you-know-if-your-child-has-hay-fever-and-how-should-you-treat-it-122853">How do you know if your child has hay fever and how should you treat it?</a>
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<p><strong>Diarrhoea, vomiting and nausea:</strong> Diarrhoea in particular can be <a href="https://health-study.joinzoe.com/post/covid-symptoms-diarrhoea">an early sign</a> of COVID, starting on the first day of infection and often getting worse from there. It’s not associated with pollen allergies.</p>
<p><strong>Muscle ache:</strong> COVID-related muscle pains can range from being mild to quite debilitating, especially when they occur alongside fatigue. Muscle aches and pains are not associated with pollen allergies.</p>
<p>Differences can also be seen within some symptoms of <a href="https://www.nhs.uk/conditions/hay-fever/">pollen allergies</a> and <a href="https://health-study.joinzoe.com/post/new-top-5-covid-symptoms">COVID</a>. For example, COVID-related coughing is commonly persistent and dry, whereas a cough associated with hay fever is more “tickly”, due to mucus from the nose presenting in the throat. Similarly, the loss of smell and taste in pollen allergies results from a blocked nose, so if you have this symptom without a blocked nose, it could be more likely to be COVID.</p>
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<img alt="A young man wrapped in a blanket feels his forehead." src="https://images.theconversation.com/files/477413/original/file-20220803-9397-f1t6qf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477413/original/file-20220803-9397-f1t6qf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477413/original/file-20220803-9397-f1t6qf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477413/original/file-20220803-9397-f1t6qf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477413/original/file-20220803-9397-f1t6qf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477413/original/file-20220803-9397-f1t6qf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477413/original/file-20220803-9397-f1t6qf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A fever isn’t a symptom of hay fever, but could indicate COVID or another respiratory infection.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/health-cold-people-concept-sick-young-1715306050">Ground Picture/Shutterstock</a></span>
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</figure>
<p>If your pollen allergy symptoms seem worse than usual, or you have one or more of the distinguishing symptoms above, it’s advisable to take a rapid COVID test. </p>
<h2>Protecting yourself</h2>
<p>Controlling allergy symptoms can help to prevent absences from work and school, and potentially facilitate earlier identification of COVID symptoms, in combination with testing. Further, although there’s no link between allergies and increased risk of COVID, pollen exposure can actually <a href="https://www.pnas.org/doi/10.1073/pnas.2019034118">weaken the body’s immunity</a> against COVID.</p>
<p>If you have a history of pollen allergies, make sure your treatment plan is current and that you have medications on hand for when you need them. Pollen exposure <a href="https://www.nhs.uk/conditions/allergies/prevention/">can be reduced</a> by avoiding outdoor activities when the pollen count is high, keeping windows closed, changing clothes after being outside, and using an air purifier. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/pollen-can-raise-your-risk-of-covid-19-and-the-season-is-getting-longer-thanks-to-climate-change-156754">Pollen can raise your risk of COVID-19 – and the season is getting longer thanks to climate change</a>
</strong>
</em>
</p>
<hr>
<p>The best ways to prevent <a href="https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public">COVID infection</a> continue to include vaccination, wearing appropriately-fitting face coverings, and physical distancing. If you’re looking for the best of both worlds, <a href="https://www.pnas.org/doi/10.1073/pnas.2019034118">a particle filter mask</a> can be protective against both pollen and COVID.</p><img src="https://counter.theconversation.com/content/188030/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Philippe B. Wilson is Chief Scientific Officer of NHS Willows Health. </span></em></p><p class="fine-print"><em><span>Samuel J. White does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>COVID symptoms have become milder over the course of the pandemic. While this is a good thing, it might make them more easily confused with allergy symptoms.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1847302022-07-12T12:33:24Z2022-07-12T12:33:24ZLight pollution is disrupting the seasonal rhythms of plants and trees, lengthening pollen season in US cities<figure><img src="https://images.theconversation.com/files/473427/original/file-20220711-13-xmyjzd.jpg?ixlib=rb-1.1.0&rect=0%2C1772%2C3712%2C2160&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some cities never sleep.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/light-trails-on-city-street-against-sky-at-night-royalty-free-image/1311603238">Noam Cohen/EyeEm via Getty Images</a></span></figcaption></figure><p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take about interesting academic work.</em></p>
<h2>The big idea</h2>
<p>City lights that blaze all night are profoundly disrupting urban plants’ phenology – shifting when their buds open in the spring and when their leaves change colors and drop in the fall. New research I coauthored shows how nighttime lights are <a href="https://doi.org/10.1093/pnasnexus/pgac046">lengthening the growing season in cities</a>, which can affect everything from <a href="https://doi.org/10.1001/jamanetworkopen.2020.7551">allergies</a> to local economies.</p>
<p>In our study, my colleagues and I analyzed trees and shrubs at about 3,000 sites in U.S. cities to see <a href="https://doi.org/10.1093/pnasnexus/pgac046">how they responded</a> under different lighting conditions over a five-year period. Plants use <a href="https://islandpress.org/books/ecological-consequences-artificial-night-lighting">the natural day-night cycle</a> as a signal of seasonal change along with <a href="https://doi.org/10.1073/pnas.1911117117">temperature</a>.</p>
<p>We found that artificial light alone <a href="https://doi.org/10.1093/pnasnexus/pgac046">advanced the date that leaf buds broke</a> in the spring by an average of about nine days compared to sites without nighttime lights. The timing of the fall color change in leaves was more complex, but the leaf change was still delayed on average by nearly six days across the lower 48 states. In general, we found that the more intense the light was, the greater the difference.</p>
<p><iframe id="gSKIJ" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/gSKIJ/9/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>We also projected the future influence of nighttime lights for five U.S. cities – Minneapolis, Chicago, Washington, Atlanta and Houston – based on different scenarios for future global warming and up to a 1% annual increase in nighttime light intensity. We found that increasing nighttime light would likely continue to shift the start of the season earlier, though its influence on the fall color change timing was more complex.</p>
<h2>Why it matters</h2>
<p>This kind of shift in plants’ biological clocks has important implications for the <a href="https://doi.org/10.1016/j.tourman.2018.08.021">economic</a>, <a href="https://theconversation.com/satellites-zoom-in-on-cities-hottest-neighborhoods-to-help-combat-the-urban-heat-island-effect-182925">climate</a>, <a href="https://doi.org/10.1001/jamanetworkopen.2020.7551">health</a> and <a href="https://doi.org/10.1098/rsbl.2014.0586">ecological</a> services that urban plants provide.</p>
<p>On the positive side, longer growing seasons could allow urban farms to <a href="https://doi.org/10.2134/jeq2013.01.0031">be active over longer periods of time</a>. Plants could also provide shade to cool neighborhoods earlier in spring and later in fall as global temperatures rise.</p>
<p>But changes to the growing season could also increase plants’ <a href="https://doi.org/10.1038/s41586-018-0399-1">vulnerability to spring frost damage</a>. And it can create a mismatch with the timing of other organisms, <a href="https://doi.org/10.1042/ETLS20190139">such as pollinators</a>, that some urban plants rely on.</p>
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<a href="https://images.theconversation.com/files/473542/original/file-20220712-22-1d5slr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Charts show the intensity of urban light in seven representative cities" src="https://images.theconversation.com/files/473542/original/file-20220712-22-1d5slr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/473542/original/file-20220712-22-1d5slr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/473542/original/file-20220712-22-1d5slr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/473542/original/file-20220712-22-1d5slr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/473542/original/file-20220712-22-1d5slr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=506&fit=crop&dpr=1 754w, https://images.theconversation.com/files/473542/original/file-20220712-22-1d5slr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=506&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/473542/original/file-20220712-22-1d5slr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=506&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Urban light intensity varies among cities, and among neighborhoods within cities.</span>
<span class="attribution"><span class="source">Yuyu Zhou</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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</figure>
<p>A longer active season for urban plants also suggests an earlier and longer pollen season, which can exacerbate asthma and other breathing problems. A study in Maryland found a <a href="https://doi.org/10.1001/jamanetworkopen.2020.7551">17% increase</a> in hospitalizations for asthma in years when plants bloomed very early.</p>
<h2>What still isn’t known</h2>
<p>How the fall color timing will change going forward as night lighting increases and temperatures rise is less clear. Temperature and artificial light together influence the fall color in a complex way, and our projections suggested that the delay of coloring date due to climate warming might stop midcentury and possibly reverse because of artificial light. This will require more research.</p>
<p>How urban artificial light will change in the future also remains to be seen.</p>
<p>One study found that urban light at night had increased <a href="https://doi.org/10.1126/sciadv.1701528">by about 1.8% per year</a> worldwide from 2012-2016. However, many cities and states are <a href="https://www.ncsl.org/research/environment-and-natural-resources/states-shut-out-light-pollution.aspx">trying to reduce light pollution</a>, including requiring shields to control where the light goes and shifting to LED street lights, which use less energy and have <a href="https://doi.org/10.1111/1365-2664.12927">less of an effect</a> on plants than traditional streetlights with <a href="https://doi.org/10.1038/35036500">longer wavelengths</a>.</p>
<figure class="align-center ">
<img alt="Cars are parked on an old brick residential street at dusk with street lights and trees lining the sidewalks." src="https://images.theconversation.com/files/473435/original/file-20220711-14-a2ls8a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/473435/original/file-20220711-14-a2ls8a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/473435/original/file-20220711-14-a2ls8a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/473435/original/file-20220711-14-a2ls8a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/473435/original/file-20220711-14-a2ls8a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/473435/original/file-20220711-14-a2ls8a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/473435/original/file-20220711-14-a2ls8a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Baltimore has been converting its streetlights to LED to save money on energy. LEDs also have less of an impact on plants.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/cobblestone-street-and-fells-point-neighborhood-at-royalty-free-image/1179432549">Cyndi Monaghan via Getty Images</a></span>
</figcaption>
</figure>
<p>Urban plants’ phenology may also be influenced by other factors, such as carbon dioxide and soil moisture. Additionally, the faster increase of temperature at night compared to the daytime could lead to different day-night temperature patterns, which might <a href="https://doi.org/10.1016/j.agrformet.2019.107832">affect plant phenology in complex ways</a>.</p>
<p>Understanding these interactions between plants and artificial light and temperature will help scientists <a href="https://doi.org/10.1038/s41558-022-01331-7">predict changes in plant processes under a changing climate</a>. Cities are already serving as natural laboratories.</p><img src="https://counter.theconversation.com/content/184730/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Yuyu Zhou receives funding from the College of Liberal Arts and Sciences at Iowa State University. </span></em></p>Artificial light is upending trees’ ability to use the natural day-night cycle as a signal of seasonal change.Yuyu Zhou, Associate Professor of Environmental Science, Iowa State UniversityLicensed as Creative Commons – attribution, no derivatives.