tag:theconversation.com,2011:/fr/topics/hayfever-1976/articlesHayfever – The Conversation2024-03-25T13:05:21Ztag:theconversation.com,2011:article/2258112024-03-25T13:05:21Z2024-03-25T13:05:21ZNasal rinsing: why flushing the nasal passages with tap water to tackle hayfever 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 hayfever 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/2152652023-10-25T23:22:10Z2023-10-25T23:22:10ZHello hay fever – why pressing under your nose could stop a sneeze but why you shouldn’t<figure><img src="https://images.theconversation.com/files/555215/original/file-20231023-17-cv1ic1.jpg?ixlib=rb-1.1.0&rect=32%2C24%2C5431%2C3612&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-pretty-woman-sneezing-front-blooming-1357485674">Shutterstock</a></span></figcaption></figure><p>If you have <a href="https://theconversation.com/sniffles-sneezing-and-cough-how-to-tell-if-its-a-simple-allergy-rather-than-the-virus-139657">hay fever</a>, you’ve probably been sneezing a lot lately. </p>
<p>Sneezing is universal but also quite unique to each of us. It is a protective reflex action outside our conscious control, to remove irritants from inside our nose. </p>
<p>The <a href="https://www.healthline.com/health/holding-in-a-sneeze">pressure in the airways</a> during a sneeze is more than 30 times greater than heavy breathing during exercise. Estimates of how fast a sneeze travels range from <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0059970">5 metres a second</a> to <a href="https://pubmed.ncbi.nlm.nih.gov/19617285/">more than 150 kilometres per hour</a>. </p>
<p>You can sometimes stop a sneeze by holding your nose or pressing underneath it. This is related to the <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/gate-control-theory">gate control theory of pain</a> and the idea you can change neural responses with external stimulation. But given the velocity of a sneeze, it might not be a good idea to stop it after it has started.</p>
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Read more:
<a href="https://theconversation.com/how-do-hay-fever-treatments-actually-work-and-whats-best-for-my-symptoms-213071">How do hay fever treatments actually work? And what's best for my symptoms?</a>
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<h2>An involuntary reflex</h2>
<p>A sneeze is initiated when sensory nerves in our nose are <a href="https://journals.sagepub.com/doi/10.1177/1753465809340571?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed">stimulated by an irritant</a> such as allergens, viruses, bacteria or even fluid. </p>
<p>The sensory nerves then carry this irritant information to the brain. </p>
<p>When a threshold amount of irritant signals reach the brain, the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2077498/">sneeze reflex is triggered</a>. A sneeze first involves a deep intake of breath and a <a href="https://www.scientificamerican.com/article/why-do-we-sneeze/">build-up of pressure inside the airways</a>. This is then followed by <a href="https://www.healthline.com/health/back-pain/back-pain-when-sneezing#sneezing-as-a-cause">contraction of the diaphragm</a> and rib muscles, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2077498/">reflex closing of the eyes</a> and a strong exhalation. </p>
<p>These are the “ah” and the “tchoo” phases of a sneeze. </p>
<p>On the exhalation of a sneeze, your tongue is lifted to the roof of your mouth. This <a href="https://www.atsjournals.org/doi/10.1164/rccm.202004-1263PP">closes off the back of the mouth</a> so the air is forced mostly through your nose. The air expelled through the nose flushes out the irritants that caused the sneeze. The “tch” sound of a sneeze is the reflexive touching of the tongue to the roof of your mouth.</p>
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<a href="https://images.theconversation.com/files/555213/original/file-20231023-29-qg8qm0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman hold hand up to nose and looks about to sneeze" src="https://images.theconversation.com/files/555213/original/file-20231023-29-qg8qm0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/555213/original/file-20231023-29-qg8qm0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/555213/original/file-20231023-29-qg8qm0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/555213/original/file-20231023-29-qg8qm0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/555213/original/file-20231023-29-qg8qm0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/555213/original/file-20231023-29-qg8qm0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/555213/original/file-20231023-29-qg8qm0.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">Activating the trigeminal touch nerve, can overwhelm the sneeze reflex.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-woman-allergy-sneezing-girl-feeling-2057416385">Shutterstock</a></span>
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<h2>The trigeminal nerves</h2>
<p>The trigeminal nerves are the <a href="https://my.clevelandclinic.org/health/body/21998-cranial-nerves">largest of our 12 pairs of cranial nerves</a> and the largest sensory nerves in the body. </p>
<p>The left and right trigeminal nerves carry sensory information from the face to the brain. This includes touch, pain and irritation sensory information from the facial skin and from inside the nose and mouth. Within each trigeminal nerve are thousands of individual nerve branches that each carry a <a href="https://journals.sagepub.com/doi/full/10.1177/1744806920901890">specific type of sensory information</a>. </p>
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Read more:
<a href="https://theconversation.com/our-vagus-nerves-help-us-rest-digest-and-restore-can-you-really-reset-them-to-feel-better-210469">Our vagus nerves help us rest, digest and restore. Can you really reset them to feel better?</a>
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<h2>Sensory nerves communicate in the spinal cord</h2>
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<span class="caption">Henry Gray’s anatomical illustration of the trigeminal nerve.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/8/83/Gray778.png">Gray's Anatomy/Wikimedia Commons</a></span>
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<p>Sensory nerves travel to the brain via the spinal cord. The sensory nerves that carry pain and irritant signals are narrow, whereas those that carry touch information are wider and faster. </p>
<p>In the spinal cord, these nerves communicate with each other via interneurons before sending their message to the brain. The interneurons are the “gates” of the <a href="https://www.physio-pedia.com/Gate_Control_Theory_of_Pain#:%7E:text=and%20trigger%20%E2%80%A2-,Introduction,be%20let%20through%20or%20restricted.">gate control theory of pain</a>.</p>
<p>A nerve carrying a pain signal tells the interneuron to “open the gate” for the pain signal to reach the brain. But the larger nerves that carry touch information can “close the gate” and block the pain messages getting to the brain.</p>
<p>This is why rubbing an injured area can reduce the sensation of pain. </p>
<p><a href="https://www.frontiersin.org/articles/10.3389/fphys.2018.01037/full">One study</a> showed stimulating the trigeminal nerves by moving the jaw reduced tooth pain. We can observe this in action when babies instinctively <a href="https://chaimommas.com/2013/11/05/what-to-expect-with-teething-and-tooth-development-chart/">bite on things or pull their ear</a> when they are teething. These actions can stimulate the trigeminal touch nerves and reduce pain signals via the gate control mechanism.</p>
<h2>So does putting your finger under your nose stop a sneeze?</h2>
<p>There are <a href="https://www.healthline.com/health/how-to-stop-sneezing">many suggestions</a> of how to stop a sneeze. These include pulling your ear, putting your tongue to the roof of your mouth or the back of your teeth, touching your nose, or even sticking your finger in your nose. </p>
<p>All of these stimulate the trigeminal touch nerves with the goal of telling the interneurons to “close the gate”. This can block the irritant signals from reaching the brain and triggering a sneeze.</p>
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Read more:
<a href="https://theconversation.com/forget-nose-spray-good-sex-clears-a-stuffy-nose-just-as-effectively-and-is-a-lot-more-fun-167901">Forget nose spray, good sex clears a stuffy nose just as effectively — and is a lot more fun</a>
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<h2>But should you stop a sneeze?</h2>
<p>What if an irritant in your nose has triggered a sneeze response, but you’re somewhere it might be considered inappropriate to sneeze. Should you stop it? </p>
<p>Closing your mouth or nose during a sneeze increases the pressure in the airways <a href="https://pubmed.ncbi.nlm.nih.gov/26914240/">five to 20 times more than a normal sneeze</a>. With no escape, this <a href="https://journals.sagepub.com/doi/10.1177/1945892418823147#:%7E:text=The%20high%20Valsalva%20pressure%20generated,to%20all%20people%20who%20sneeze.">pressure has to be transmitted elsewhere</a> and that can damage your eyes, ears or blood vessels. Though the risk is low, brain aneurysm, ruptured throat and collapsed lung have been <a href="https://www.healthline.com/health/holding-in-a-sneeze#can-holding-a-sneeze-kill-you">reported</a>. </p>
<p>So it’s probably best to try and prevent the sneeze reflex by treating allergies or addressing irritants. Failing that, embrace your personal sneeze style and <a href="https://theconversation.com/handkerchief-or-tissue-which-ones-better-for-our-health-and-the-planet-213065">sneeze into a tissue</a>. </p>
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Read more:
<a href="https://theconversation.com/handkerchief-or-tissue-which-ones-better-for-our-health-and-the-planet-213065">Handkerchief or tissue? Which one's better for our health and the planet?</a>
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<img src="https://counter.theconversation.com/content/215265/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>The trigeminal nerve is at the heart of the sneeze reflex. But stopping a sneeze once triggered can increase its force and redirect pressure in dangerous ways.Theresa Larkin, Associate professor of Medical Sciences, University of WollongongJessica Nealon, Lecturer in Medical Sciences (Neuroscience), University of WollongongLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1697532021-10-14T14:36:56Z2021-10-14T14:36:56ZPasha 127: Allergies vs rooibos: can this South African plant help sufferers?<figure><img src="https://images.theconversation.com/files/426182/original/file-20211013-19-1aqitzz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Nasal allergy is a common problem in South Africa. It is estimated that 20% to 30% of adults in South Africa suffer with <a href="https://www.news24.com/health24/Medical/Allergy/Overview/how-common-are-allergies-20180313">allergic rhinitis or hay fever</a>. House dust mites and tree pollen are the most common reasons for this. Often, people have to rely on allergy medication to deal with the problem. </p>
<p>But new <a href="https://www.sciencedirect.com/sdfe/pdf/download/eid/1-s2.0-S0378874119336785/first-page-pdf">research</a> is under way to see if a plant native to South Africa can help. Rooibos, scientifically known as <em>Aspalathus linearis</em>, is being explored as a treatment for nasal allergies. The <a href="https://pubmed.ncbi.nlm.nih.gov/31672527/">studies</a> are testing its impact by having people drink rooibos tea in specific doses and through nasal irrigation using rooibos tea.</p>
<p>In today’s episode of Pasha, Jonny Peter, associate professor, <a href="https://lunginstitute.co.za/aiu-2/">unit head</a> and head of the Division of Allergology and Clinical Immunology at Groote Schuur Hospital at the University of Cape Town, discusses his latest research. He also discusses the challenges with understanding whether you have COVID-19 or are suffering from nasal allergies.</p>
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<p><strong>Photo:</strong><br>
“African young woman covered with blanket blowing running nose.”
By fizkes found on <a href="https://www.shutterstock.com/image-photo/ill-african-young-woman-covered-blanket-1444224857">Shutterstock</a>.</p>
<p><strong>Music:</strong>
“Happy African Village” by John Bartmann, found on <a href="http://freemusicarchive.org/music/John_Bartmann/Public_Domain_Soundtrack_Music_Album_One/happy-african-village">FreeMusicArchive.org</a> licensed under <a href="https://creativecommons.org/publicdomain/zero/1.0/">CC0 1</a>.</p>
<p>“Ambient guitar X1 - Loop mode” by frankum, found on <a href="https://freesound.org/people/frankum/sounds/393520/">Freesound</a> licensed under <a href="http://creativecommons.org/licenses/by/3.0/">Attribution License.</a></p><img src="https://counter.theconversation.com/content/169753/count.gif" alt="The Conversation" width="1" height="1" />
Good news may be on the horizon for people who suffer from nasal allergies.Ozayr Patel, Digital EditorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1396572020-07-27T20:01:03Z2020-07-27T20:01:03ZSniffles, sneezing and cough? How to tell if it’s a simple allergy rather than The Virus<figure><img src="https://images.theconversation.com/files/344984/original/file-20200701-108321-15zcosh.jpg?ixlib=rb-1.1.0&rect=0%2C14%2C1000%2C651&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-young-woman-sitting-indoors-holding-1354368317">Shutterstock</a></span></figcaption></figure><p>We’re told to stay home if we feel unwell during the COVID-19 pandemic. But what if your sniffles, sore throat or cough aren’t infectious? What if they’re caused by hayfever or another allergic reaction? You may be doing a lot more isolating than you need to. </p>
<p>Although it can sometimes be challenging, there are ways to tell apart respiratory symptoms caused by a virus and those caused by an allergy. This approach may help prevent Australia’s COVID-19 testing capacity from being overwhelmed.</p>
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Read more:
<a href="https://theconversation.com/health-check-whats-the-right-way-to-blow-your-nose-74977">Health Check: what's the right way to blow your nose?</a>
</strong>
</em>
</p>
<hr>
<h2>What causes hayfever?</h2>
<p>Around <a href="https://www.nps.org.au/consumers/managing-hay-fever#what-is-hay-fever?">one in five</a> (21%) of Australians suffer seasonal allergic rhinitis – more commonly known as hayfever. If each of these experiences a few episodes of hayfever annually, that would require between 10 million and 20 million COVID-19 tests to exclude infectious causes from allergies alone. </p>
<p>Hayfever has many of the same symptoms as viral respiratory infections, such as colds and mild flu-like illnesses, as well as COVID-19. This is because rhinitis refers to inflammation of the nose, which has many causes.</p>
<p>Hayfever is <a href="https://www.allergy.org.au/patients/fast-facts/hay-fever-allergic-rhinitis">caused by</a> your nose and/or eyes coming into contact with microscopic allergens in the environment, such as pollens (from grasses, weeds or trees), dust mites, moulds and animal hair. </p>
<p>Your immune system <a href="https://www.mayoclinic.org/diseases-conditions/hay-fever/symptoms-causes/syc-20373039?p=1">identifies</a> these airborne substances as harmful and produces antibodies against them. The next time you come into contact with them, these antibodies signal your immune system to release chemicals such as histamine into your bloodstream, causing the inflammation that leads to hayfever symptoms.</p>
<p>Hayfever traditionally has a <a href="https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/pollen-allergy">seasonal spike</a> in late winter and spring, when pollen counts are highest from flowering trees and grass seeds.</p>
<p>But in many areas of Australia, there may be more hayfever in autumn, due to two common sources of allergies: moulds, and an <a href="https://awareenvironmental.com.au/whats-new/deal-autumn-allergies-asthma/">autumn spike</a> in indoor dust mites.</p>
<p>A warming climate has also <a href="https://link.springer.com/article/10.1007/s40641-015-0018-2">been linked with</a> increased levels of pollens and environmental allergens, and a rise in asthma and hayfever severity.</p>
<h2>What are the symptoms?</h2>
<p>Whether you have seasonal hayfever, longer-term perennial or <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.0108-1675.2004.00388.x">vasomotor rhinitis</a>), or a viral infection, you’re likely to have similar cold and flu-like symptoms.</p>
<p>You’ll have either a runny or stuffy nose. Other symptoms include sore throat; sneezing; cough; post-nasal drip - nasal mucus going down the back of your throat; and fatigue.</p>
<p>But there are two classic <a href="https://www.mayoclinic.org/diseases-conditions/hay-fever/symptoms-causes/syc-20373039?p=1">hayfever symptoms</a> that can help you tell allergies and viruses apart. Hayfever can cause you to have an itchy nose or throat; and when it’s more severe it can cause swollen, blue-coloured skin under the eyes (called allergic shiners).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/344987/original/file-20200701-108347-zmx7cg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/344987/original/file-20200701-108347-zmx7cg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/344987/original/file-20200701-108347-zmx7cg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=289&fit=crop&dpr=1 600w, https://images.theconversation.com/files/344987/original/file-20200701-108347-zmx7cg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=289&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/344987/original/file-20200701-108347-zmx7cg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=289&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/344987/original/file-20200701-108347-zmx7cg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=363&fit=crop&dpr=1 754w, https://images.theconversation.com/files/344987/original/file-20200701-108347-zmx7cg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=363&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/344987/original/file-20200701-108347-zmx7cg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=363&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dark circles under your eyes can be a classic symptom of hayfever.</span>
<span class="attribution"><a class="source" href="https://www.mayoclinic.org/diseases-conditions/hay-fever/symptoms-causes/syc-20373039?p=1">www.shutterstock.com</a></span>
</figcaption>
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<h2>Can we tell them apart?</h2>
<p><strong>Fever, sore muscles or muscle weakness</strong></p>
<p>Hayfever, despite its name, does not cause increased body temperature. Flu-like illnesses do cause fever, and sore muscles (myalgia), malaise and fatigue. </p>
<p>Allergies such as hayfever may cause a slight malaise without the other symptoms, probably due to a stuffy nose and poor sleep.</p>
<p><strong>Snoring, dark circles under the eyes and sleep</strong></p>
<p>The nasal congestion from hayfever and other types of rhinitis often increases the potential to snore during sleep. And if you have those dark circles under the eyes, that’s <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jocd.12549">likely down to</a> chronic poor-quality sleep, as nasal congestion and snoring worsen.</p>
<p><strong>Itchy nose and eyes, plus sneezing</strong></p>
<p>An itchy nose and eyes are classic hayfever symptoms, as is intense, prolonged sneezing.</p>
<p>You can sneeze with a cold or flu, but usually only in the first few days of the infection.</p>
<p><strong>Longer-lasting symptoms</strong></p>
<p>Allergic reactions tend to come and go from day to day, or even from hour to hour, particularly if some environments are the source of the offending allergens. Perennial rhinitis can be present for weeks or months, far longer than any viral cold or flu.</p>
<p>It is rare for a cold to last more than a week, as the body has fought off the virus by that time. Exceptions to this are the cough and sinus symptoms that were triggered by the virus but persist for other reasons. </p>
<p><strong>Antihistamines</strong></p>
<p>If your nasal symptoms <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2907832/">improve</a> with antihistamine medication, then you likely have an allergy or hayfever. Antihistamines <a href="https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001267/abstract">do not alleviate symptoms</a> of the common cold.</p>
<p>However, if your allergic reaction is more severe, antihistamines alone, even in larger doses than stated on the packet, <a href="https://www.nature.com/articles/s41533-016-0001-y">may be insufficient</a> to fully control symptoms, and a variety of nasal sprays may have to be added to the treatment.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/coronavirus-or-just-a-common-cold-what-to-do-when-your-child-gets-sick-this-winter-140727">Coronavirus or just a common cold? What to do when your child gets sick this winter</a>
</strong>
</em>
</p>
<hr>
<h2>Why do we need to differentiate viral from allergic causes?</h2>
<p>In “normal” times we usually treat the symptoms of viral infections. However, amid the COVID-19 outbreak we need a clearer picture of what might be causing our symptoms so we get tested when it matters, and not for undiagnosed hayfever.</p>
<p>But it’s not easy to tell viral and allergic rhinitis apart. People with hayfever also get viral colds and flus, further complicating the picture.</p>
<p>If you think your symptoms may be due to allergy, it is safe to try a <a href="https://pubmed.ncbi.nlm.nih.gov/7719897/">double dose of non-sedating antihistamine</a>. Sedating antihistamines should be avoided in young children, and taken with caution in adults. If your symptoms improve significantly within an hour, your symptoms are likely hayfever or another allergic reaction.</p>
<p>However, if your symptoms are different to previous hayfever episodes, or your symptoms don’t improve after taking an antihistamine, that’s another matter. Stay at home until you can get tested for COVID-19.</p>
<p>Anyone with only partially treated and controlled hayfever will need to realise that your sniffles and sneezes are going to be distressing to your fellow commuter, diner or shopper. So you may need some medical assistance to more fully manage your allergic condition.</p><img src="https://counter.theconversation.com/content/139657/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David King 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>Although it can sometimes be challenging, there are ways to distinguish respiratory symptoms caused by a virus and those caused by an allergy.David King, Senior Lecturer in General Practice, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1150172019-04-15T11:21:15Z2019-04-15T11:21:15ZDNA analysis finds that type of grass pollen, not total count, could be important for allergy sufferers<figure><img src="https://images.theconversation.com/files/268955/original/file-20190412-76840-ewwo7w.jpg?ixlib=rb-1.1.0&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-man-sneezes-because-allergy-ragweed-1039352290?src=edrdJA1AXwsin1njFbOuRQ-1-58">Elizaveta Galitckaia/Shutterstock</a></span></figcaption></figure><p>As the winter cold is replaced by warmer temperatures, longer days and an explosion of botanical life, up to 400m people worldwide will develop allergic reactions to airborne pollen from trees, grasses and weeds. Symptoms will range from itchy eyes, congestion and sneezing, to the aggravation of asthma and an associated cost to society that <a href="http://www.globalasthmanetwork.org/publications/Global_Asthma_Report_2014.pdf">runs into the billions</a>. </p>
<p>Ever since the 1950s, countries around the world have been recording pollen counts to create forecasts for allergy sufferers. In the UK this forecast is provided by <a href="https://www.metoffice.gov.uk/public/weather/pollen-forecast/#?tab=map&map=Pollen&fcTime=1554375600&zoom=5&lon=-4.00&lat=55.71">the Met Office</a> in collaboration with the University of Worcester. To date, pollen forecasts have been based on counting the total number of grains of pollen in the air from trees, weeds and grass. The pollen is collected using air sampling machines that capture the particles on a slowly rotating sticky drum. </p>
<p>However, while these forecasts focus on the level of all pollens in the air, people suffer from allergic reactions to different types of pollen. Grass pollen, for example, is the most harmful aeroallergen – more people are allergic to grass pollen <a href="https://erj.ersjournals.com/content/24/5/758">than any other airborne allergen</a>. And now our own <a href="http://dx.doi.org/%2010.1038/s41559-019-0849-7">preliminary health data</a> suggests that allergies to this pollen vary across the grass flowering season. </p>
<h2>Pinpointing pollen</h2>
<p>In an effort to improve the accuracy of pollen counts and forecasts, we have been working <a href="https://theconversation.com/were-working-on-a-more-accurate-pollen-forecasting-system-using-plant-dna-97474">on a new project</a> to distinguish between different types of grass pollen in the UK. The aim is to find out what species of pollen are present across Britain throughout the grass flowering season. </p>
<p>Microscopes are used to identify the pollen of many allergenic tree and weeds, but unfortunately this can’t be done for grass pollen, since all grass pollen grains look highly similar underneath a microscope. This means it is almost impossible to routinely distinguish the species of grass they come from using visual observation.</p>
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<p>So, over the past few years, our research team, <a href="http://pollergen.bangor.ac.uk/">PollerGEN</a>, has been investigating whether a new wave of approaches, including molecular genetics, can be used to identify different airborne grass pollens instead. One method that our team has employed to identify the pollen relies on using DNA sequencing to examine millions of short sections of DNA (also called barcode markers). These markers are unique to each species or genus of grass pollen. </p>
<p>This approach is called “metabarcoding” and it can be used to analyse DNA derived from mixed communities of organisms, as well as DNA from many different types of environmental sources (for example, soil, aquatic sources, honey and the air). It means that we can assess the biodiversity of hundreds to thousands of samples. In particular, it has allowed us to analyse pollen DNA collected by aerial samplers at 14 rooftop locations across Britain.</p>
<h2>Flowering season</h2>
<p>By comparing the pollen we captured to samples in the <a href="https://botanicgarden.wales/science/collections/barcode-uk/">UK plant DNA barcode library</a> (an established reference DNA database of correctly identified grass species) we have been able to identify different types of grass pollen from complex mixtures of airborne pollen. This has allowed us to visualise how different types of grass pollen are distributed throughout Britain across the grass flowering season. </p>
<p>While there was a real chance that aerial pollen mixtures could be very varied and haphazard – due to the mobility of pollen in the environment and the fact that different grasses flower at different times of the season – our newly published study has found that <a href="http://dx.doi.org/%2010.1038/s41559-019-0849-7">this is not the case</a>. We have found that the composition of airborne pollen resembles a seasonal progression of diversity, featuring early, then mid and late-season flowering grasses. </p>
<p>By combining other historical and contemporary data, we also found that as the grass flowering season progresses, airborne pollen follows a sensible, but delayed appearance from the first flowering times noted from the ground. This means that different types of grass pollen are not present throughout each period of the flowering season. They disappear from the environmental mixture.</p>
<p>This research is important to more than just our understanding of plants. Our own emerging evidence suggests that over-the-counter medications are not uniform throughout the grass flowering season. So certain types of grass pollen may be contributing more to allergenic disease than others. It could be that when symptoms are particularly bad, allergies are caused by the type of grass pollen in the air, not just the amount. </p>
<p>In the next few months, we will be looking into different forms of pollen and health data, to investigate links between the biodiversity of aerial pollen and allergenic symptoms. The overarching aim of our work is to eventually provide better forecasting, planning and prevention measures to enable less people to suffer from grass allergenic disease.</p><img src="https://counter.theconversation.com/content/115017/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Creer receives funding from The Natural Environment Research Council.</span></em></p><p class="fine-print"><em><span>Georgina Brennan receives funding from The Natural Environment Research Council.</span></em></p>Pollen counts focus on the amount of grains in the air, but it could be the species that are more important.Simon Creer, Professor in Molecular Ecology, Bangor UniversityGeorgina Brennan, Postdoctoral Research Officer, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/974742018-06-21T08:42:48Z2018-06-21T08:42:48ZWe’re working on a more accurate pollen forecasting system using plant DNA<figure><img src="https://images.theconversation.com/files/224120/original/file-20180620-137708-1n79gp6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Hayfever.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pollen-allergy-girl-sneezing-field-flowers-93088627?src=pmx7uDSqeZc6oRfdhaCXeQ-1-10">Alex Cofaru/Shutterstock</a></span></figcaption></figure><p>Most people enjoy the warmer, longer days that summer months bring – but plant allergy sufferers will have mixed emotions. Roughly <a href="http://erj.ersjournals.com/content/24/5/758">one in five Europeans</a> suffers from allergic reactions to tree, grass and weed pollen causing pollinosis, <a href="https://theconversation.com/explainer-what-is-hay-fever-and-why-do-you-have-it-27034">hay fever</a> and <a href="https://theconversation.com/whats-the-link-between-hay-fever-and-asthma-and-how-are-they-treated-64740">allergic asthma</a>.</p>
<p>Allergies to substances such as pollen are driven by errors in the body’s immune system, which means it mounts a response to otherwise benign substances from plants. On first exposure to pollen, the body decides if some of the otherwise harmless proteins in the pollen are dangerous. If it decides they are, the immune system produces immunoglobin E (IgE) antibodies in a process called sensitisation. </p>
<p>The next time the body is exposed to pollen, it remembers the proteins and mounts another response. The IgE antibodies detect the pollen in, or on, the body, and cause cells to release histamine and a variety of other chemicals. This <a href="https://theconversation.com/hay-fever-survival-guide-why-you-have-it-and-how-to-treat-it-34000">results in symptoms</a> ranging from itchy eyes and nose, to production of mucous, inflammation and sneezing fits. </p>
<p>But while we know that “pollen” causes this response, at present we still don’t know all the types of pollen that cause the body to react. </p>
<h2>Forecasting hay fever</h2>
<p>In the UK, a <a href="https://www.metoffice.gov.uk/public/weather/pollen-forecast/#?tab=map&map=Pollen&fcTime=1527764400&zoom=5&lon=-4.00&lat=55.71">daily pollen forecast</a> is generated by the UK Met Office in collaboration with the National Pollen and Aerobiology Unit (NPARU), to help allergy sufferers. This forecast is created using data from a network of pollen traps which operate throughout the main pollen season (March to September) and measure how many pollen grains are present on a daily basis. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/224175/original/file-20180621-137750-1dr5fn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/224175/original/file-20180621-137750-1dr5fn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/224175/original/file-20180621-137750-1dr5fn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/224175/original/file-20180621-137750-1dr5fn9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/224175/original/file-20180621-137750-1dr5fn9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/224175/original/file-20180621-137750-1dr5fn9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/224175/original/file-20180621-137750-1dr5fn9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/224175/original/file-20180621-137750-1dr5fn9.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">Sweet vernal, an early flowering grass.</span>
<span class="attribution"><span class="license">Author provided</span></span>
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</figure>
<p>Pollen from different types of tree can be identified using microscopes, but grass pollen grains all look the same. As a result the pollen forecast for grasses (of which there are 150 types in the UK alone) is based on the broad, undifferentiated category of “grass”. That is despite grass pollen being the single most important outdoor aeroallergen. </p>
<p>We already know that different species of grass pollinate at different times in the year, and allergic reactions can occur at different times throughout the allergy season. What we need to figure out is whether allergies are caused by all species, specific species, or a combination of species of grasses. We also need to learn how pollen grains change in composition in time and space. While pollen is known for being very tough and is often well preserved in sediments, it can be very fragile in certain circumstances, such as bursting when in contact with rain drops. </p>
<p>To find out which grasses are linked to the allergic response, we need to know many things, such as where and when species of grass are releasing pollen. We also need to uncover how the pollen moves through the atmosphere, quantify the exposure of grass pollen species in time and space, and work out how allergies develop across broad geographical and temporal scales.</p>
<h2>The #PollerGEN project</h2>
<p>Our Natural Environment Research Council (NERC) <a href="http://pollergen.bangor.ac.uk/">PollerGEN project</a> team is now working on a way to detect airborne pollen from different species of allergenic grass. We’re also developing new pollen source maps, and modelling how pollen grains likely move across landscapes, as well as identifying which species are linked with the exacerbation of asthma and hay fever.</p>
<p>We’re going to be using a <a href="https://botanicgarden.wales/science/collections/barcode-uk/">new UK plant DNA barcode library</a>, as well as environmental genomic technologies to identify complex mixtures of tree and grass pollens from a molecular genetic perspective. By combining this information with detailed source maps and aerobiological modelling, we hope to redefine how pollen forecasts are measured and reported in the future.</p>
<p>We have just started the third year of pollen collection and hope to road test the combined forecasting methods over the next year. In the long run, our vision is to be able to provide specific pollen forecasts for grass, and unravel which species of grass pollen are most likely causing allergic responses. More broadly, we also want to provide information to healthcare professionals and charities, who can translate this information to help pollen allergy sufferers live healthier and more productive lives.</p>
<p>In the meantime, if you suffer from pollen allergies, sneeze or wheeze during spring, speak to a doctor or pharmacist to prepare an action plan. You can also get support from <a href="https://www.allergyuk.org/">Allergy UK</a>, and information about the pollen forecast from the <a href="https://www.metoffice.gov.uk/public/weather/pollen-forecast/">UK Met Office</a>.</p><img src="https://counter.theconversation.com/content/97474/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Creer receives funding from the Natural Environment Research Council. </span></em></p><p class="fine-print"><em><span>Georgina Brennan 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>Unlocking the genetic code of certain grasses could help allergy sufferers.Simon Creer, Professor in Molecular Ecology, Bangor UniversityGeorgina Brennan, Postdoctoral Research Officer, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/489912015-10-28T19:29:38Z2015-10-28T19:29:38ZSpring has sprung: how changes in weather affect our health<figure><img src="https://images.theconversation.com/files/99132/original/image-20151021-15430-sq6hoq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">From hot to cold and cold to hot, the weather can make a difference to our health.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/39877441@N05/17048958441/in/photolist-rYynnk-e8xhpt-msghQv-rHGBXT-4tzYhP-6okniT-81v4SH-bELWzF-bm1dPE-9rSWSE-VD7j-9ntM7b-scBoof-rRjyh5-qzvbPR-kJQJE3-mijTet-9wT8dB-7JvMLM-7QaxNS-ea8K6C-4WxzYv-6uUJZZ-saJBnD-rv1Zzw-9w7bSJ-ekuWpB-9xWGjq-r1YHih-7STurY-qWrUTn-9WVxsF-np1pck-FCB3A-e3CMCf-qQq9wd-sbVz7H-9tXGiz-byZymy-mxAzAC-4Ecda6-eeBeLB-cxAsMb-4yeYhy-9viTP5-s6xXZB-2AhVC-nndjL3-snruCW-cxArNd">Michael Levine-Clark/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Seasonal fluctuations in disease have been recognised for <a href="https://ebooks.adelaide.edu.au/h/hippocrates/aphorisms/">millennia</a>. Until recent times, these phenomena were ascribed to changes in the weather. It’s easy to understand why.</p>
<p>This time of the year the weather is predictably unpredictable. Summer is mostly hot. Winter is mostly cold. But spring can be either, on successive days or even in the space of a few hours.</p>
<p>This kind of unsettled weather can be <a href="https://www.youtube.com/watch?v=TXMEVTtAZkI">vaguely discontenting</a>. At least half of all adults claim to experience changes in their health with the <a href="http://www.ncbi.nlm.nih.gov/pubmed/15338386">changing weather</a>, including more frequent headaches, joint pain, tiredness, and even catching more colds. </p>
<p>Of course colds are caused by <a href="https://theconversation.com/mondays-medical-myth-you-can-catch-a-cold-by-getting-cold-2488">viruses</a>, not the weather. But as the air temperature and humidity changes around us, so does the <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0024618">feeling of stuffiness</a> of our nose. </p>
<p>Even though the nose does not actually block, hotter and humid air will make it feel more congested, like when we’re in the shower. But once we step out, the blast of colder less humid air makes the nose suddenly feel more open, creating that <a href="http://www.dailymail.co.uk/news/article-3261774/Melbourne-s-temperature-drops-11-degrees-just-THREE-MINUTES.html">freshening sensation</a> in our head. The same thing happens in reverse when we step from air-conditioned cool indoors into the humid heat outside, making our head feel stuffy.</p>
<p>People <a href="http://www.ncbi.nlm.nih.gov/pubmed/8014037">prone to headaches</a> report <a href="http://www.ncbi.nlm.nih.gov/pubmed/24477598">more episodes</a> in changeable spring weather than in summer or winter. </p>
<p>The vast majority of <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1479-8077.2004.00099.x/abstract;jsessionid=24BE96532E1172DAD6B53E9897C5A31A.f01t01">people with arthritis</a> or chronic back pain feel more discomfort on stormy, cold or damp days, which improves as the weather warms and becomes more constant.</p>
<p>Whether these are a direct effect of the weather or an indirect one (related to the profound effects of seasonal weather on mood, behaviour, diet, physical activity, mobility, participation, perception of illness, pain and many other factors) is unknown.</p>
<p>The weather outside can certainly significantly influence how we <a href="http://www.ncbi.nlm.nih.gov/pubmed/21842988">feel</a>. Not by as much as most people think and not the same way in everyone. But enough to make a difference. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/98951/original/image-20151020-23245-10r3pk5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/98951/original/image-20151020-23245-10r3pk5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/98951/original/image-20151020-23245-10r3pk5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/98951/original/image-20151020-23245-10r3pk5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/98951/original/image-20151020-23245-10r3pk5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/98951/original/image-20151020-23245-10r3pk5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/98951/original/image-20151020-23245-10r3pk5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/98951/original/image-20151020-23245-10r3pk5.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>
<figcaption>
<span class="caption">The weather might effect us less than some think, but enough to make a difference.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/ell-r-brown/4178017589/">Elliott Brown/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Sunshine is probably a critical element. We have special <a href="http://www.ncbi.nlm.nih.gov/pubmed/20691201">sensors</a> in our eyes that feed back the intensity of light to our brains to regulate our biological and hormonal rhythms as well as our alertness and mood. </p>
<p>Our skin uses the ultraviolet radiation in sunlight to make <a href="https://theconversation.com/putting-some-d-in-your-day-174">vitamin D</a> which also has important vital functions for health and well-being. </p>
<p>Sunny weather also puts us closer to our comfort zone at around 20 degrees celsius when we neither need to sweat to keep cool or move/shiver to keep warm. The hotter we get above this or the lower we go the less comfortable we feel. This plays on our emotions and the health that results from them.</p>
<h2>Can the spring weather really make us sick?</h2>
<p>Many cultures describe “an ill wind”, which rapidly changes the temperature and triggers symptoms of poor health. The most famous examples are the <a href="http://www.manfredkaiser.com/ill_winds.html">Föhn wind</a> in Europe and the <a href="http://www.ncbi.nlm.nih.gov/pubmed/9100399">Chinook</a> of the Rocky Mountains.</p>
<p>In Australia, pollen and dust carried by spring northerly winds that whip them up, act as an irritant to eyes, noses and lungs, especially, but not only, in those with allergies. </p>
<p>The moist air associated with seasonal <a href="http://theconversation.com/explainer-what-is-thunderstorm-asthma-4159">thunderstorms</a> can also concentrate and break up pollen and pollution into smaller particles which are more easily inhaled deep into the lungs and trigger asthma attacks. Warm and moist conditions also promote the release of <a href="http://www.allergiesexplained.com/pages/Seasonal%20Rhinitis%20and%20Asthma.htm">fungal spores</a> which can set off allergies in some people. </p>
<p>The onset of the debilitating autoimmune-disease multiple sclerosis (MS) or episodes of MS relapse are also more common in <a href="http://www.ncbi.nlm.nih.gov/pubmed/26359987">springtime</a>. Whether this relates to the latent effect of winter infections on immunity or seasonal fluctuations in our body’s natural immune-modifying substances such as vitamin D or melatonin is unknown.</p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/6848200">Breast cancer</a> is also more commonly diagnosed in spring and early summer, and this association is more pronounced the further you get from the equator, where seasonal change is most dramatic. A spring upsurge for <a href="http://ajcn.nutrition.org/content/early/2012/11/27/ajcn.112.039222.full.pdf">prostate cancer</a> diagnosis is also seen in men. </p>
<p>But this is probably just due to behaviour. Spring is traditionally the season we try to get things in order, such as <a href="https://en.wikipedia.org/wiki/Spring_cleaning">spring cleaning</a>.</p><img src="https://counter.theconversation.com/content/48991/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Merlin Thomas 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>Changes in temperature and season do affect our health – and not just when the weather turns cold.Merlin Thomas, Adjunct Professor of Preventive Medicine, Baker Heart and Diabetes InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/454602015-08-03T10:43:02Z2015-08-03T10:43:02ZAsthma rates falling but eczema and hay fever stand still. What does this tell us about allergies?<figure><img src="https://images.theconversation.com/files/90357/original/image-20150730-25742-ifbu5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Asthma rates in the UK look to be falling</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=&searchterm=asthma&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=291685250">parinyabinsuk</a></span></figcaption></figure><p>You might have thought that health specialists would closely monitor the prevalence of allergies in the population, especially when they are far more common than they used to be. In fact, it happens less than you would think. For asthma, for example, the government <a href="http://www.hscic.gov.uk/hes">publishes statistics</a> on the numbers of people that are admitted to hospital or die from the condition, but it does not publish a running total of how many people are affected overall. </p>
<p>The University of Aberdeen is one of very places that does regularly publish data on childhood asthma, eczema and hay fever, going back as far as 1964. Though we only survey what is happening in the city, the figures are closely watched because they have a very good record of predicting the incidence of these allergies across the rest of western Europe. </p>
<p>When we published our five-yearly report on July 29, it <a href="http://www.scotsman.com/news/health/child-asthma-sufferers-down-by-nearly-a-third-1-3844603">showed that</a> childhood prevalence of asthma had fallen by a third to around 20% following a long rise over decades. Reasons are likely to include improved air quality, reduced smoking, changing diets and improved diagnosis. </p>
<p>The figures showed something else very interesting too. Since our study began, in line with most other research into the prevalence of allergies, rises and falls in the rate of asthma have been broadly followed by those for eczema and hay fever. Not on this occasion, though. The latter two complaints stayed around their previous levels as asthma rates fell on their own. </p>
<p>This doesn’t look like a freak occurrence. We saw some evidence of this <a href="http://www.ncbi.nlm.nih.gov/pubmed/21068081">in 2009</a>, as did <a href="http://ije.oxfordjournals.org/content/37/3/559.full">another study</a> in Australia the year before. It looks like a trend is developing. So what is going on?</p>
<h2>The allergy debate</h2>
<p>Specialists have for many years debated the nature of allergy. We know that allergies are associated with the immune system producing an antibody called <a href="http://www.worldallergy.org/professional/allergic_diseases_center/ige/">immunoglobin E (IgE)</a>, which binds itself to common things in our environment such as grass pollen and house dust mites when they come in contact with the body. The classic view was that allergic people overproduced this antibody, which in turn produced substances that caused the inflammation and irritation in complaints such as asthma or eczema. In short, asthma, eczema and hay fever were thought to be caused by being allergic. </p>
<p>There’s a flaw in this argument, though. If an organism is going to become allergic to something outside it, it must be exposed through a crack in the skin. For this reason, some specialists <a href="http://www.ncbi.nlm.nih.gov/pubmed/10669837">began arguing</a> from the early 1990s that you became allergic to something because there was a problem with, in the case of asthma, the cells lining the lungs. In this scenario the primary “abnormality” is in these lung cells, which leads to asthma and also does not provide an effective barrier against environmental exposures. The immune system is fundamentally normal and is just doing what it is meant to do and responding to exposures which “leak” through into the body. The immune response then adds to the problem caused by the lung-cell abnormality. </p>
<h2>Stat power</h2>
<p>Public opinion can be hard to change (and medical opinion harder still) but we are now at a point where most medical people would accept that it is not the allergy that causes asthma – though some certainly still believe it. What we don’t have yet is proof, though we will hopefully produce some over the next few years at this university and with colleagues across the UK through our studies into the lung cells of small children. </p>
<p>In the meantime, this is where the divergence in our stats comes in. If being allergic caused allergies, you would expect the rates of asthma, hay fever and eczema across the population to roughly move in unison. In other words, for many years our stats and those from other sources supported the old theory. </p>
<p>At the same time, though, supporters of that theory had to contend with the fact that having one of these allergies has never meant you would have all of them – a correlation you would also expect if the theory were true. In our most recent figures, for instance, only 55% of children with asthma had hay fever, and only 64% of them had eczema. This weakish correlation has always supported the newer theory – and the divergence now backs this up. It adds to the probability that we misunderstood the nature of allergy for a long time. It does leave the mystery of why the allergy rates moved in unison for so long, but that is a matter for another day. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/90358/original/image-20150730-25740-xknbct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/90358/original/image-20150730-25740-xknbct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/90358/original/image-20150730-25740-xknbct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/90358/original/image-20150730-25740-xknbct.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/90358/original/image-20150730-25740-xknbct.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/90358/original/image-20150730-25740-xknbct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/90358/original/image-20150730-25740-xknbct.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/90358/original/image-20150730-25740-xknbct.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">The eczema/asthma correlation is far from 100%</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=&search_tracking_id=W2TCwn9MDm-GiXw0980sig&searchterm=eczema&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=296161622">sumroeng chinnapan</a></span>
</figcaption>
</figure>
<p>This doesn’t have a huge bearing on our ability to treat asthma. It is more about knowing that we understand a process correctly and this is important to preventing asthma. In terms of treatment, the general view is that asthma can’t be cured. But there is <a href="http://www.davidhideallergyresearch.co.uk/prevention.html">mounting evidence</a> that it can be prevented by exposing babies who are genetically predisposed to the condition to the right environment while they are in the womb and then for the first couple of years of their life. What we still don’t know is what the right environment is, but modifying exposures to cats, dogs, mould, smoking, breastfeeding and weaning diet are likely to be important. </p>
<p>I can see us reaching a point in ten or 15 years where pregnant mothers with at-risk unborn children will be offered a course of “environmental modification” treatment, possibly as simple as a pill. Ensuring that the immune system of children at increased risk for asthma is flooded by exposed to allergens at a sufficiently early stage will switch off any later IgE production. Although they may still have the lung-cell abnormality, at least they don’t get the added hit of an allergic immune system. In this sense at least, a cure for asthma may not be far away.</p><img src="https://counter.theconversation.com/content/45460/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steve Turner 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>There have long been two schools of thought on what causes allergies. New stats are much more helpful to one than the other.Steve Turner, Consultant Paediatrician and Senior Lecturer in Child Health, University of AberdeenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/439292015-06-29T13:08:16Z2015-06-29T13:08:16ZSport can help with your asthma if you learn how to listen to your body<figure><img src="https://images.theconversation.com/files/86511/original/image-20150626-18214-6u34h1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Petra Kvitova: champion asthmatic.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/43555660@N00/14543240281/in/photolist-oa8UE6-eRJmbe-eh1WAn-ehkt2p-eRJpzX-tLtqCo-tLtqWQ-ehrcxJ-ehktcR-ehrcib-ehrbFm-ehkroi-eh1Xpv-eh1VXT-u6KfoS-p3dnzj-p4Z3Ke-p5ffgp-nSWCvE-eRVK3d-eRVLPE-eRVKUW-nZHoLk-nZTGjh-u3GfYy-u44umB-eRVJcQ-8yEQD6-fk1Z3Q-o11zEV-cmYmuN-eWWtRR-o2M6x4-nXX8gG-oHh28f-oXGSaj-oHgppy-oHgcLF-oZtd2z-oHffvd-oZGTxy-oXHkLw-oHgtNw-oXJaU5-oHfBLC-oHgjdk-oZJARB-oHgsNr-oHgP1E-oZKr8r">Carine06</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>It’s Wimbledon season again and many will be wondering whether champions Petra Kvitova and Novak Djokovic will repeat their 2014 winning performances; it’s worth remembering that both are asthmatic.</p>
<p>There are more than 230m people in the world with asthma and attacks result in a hospitalisation every <a href="http://www.who.int/respiratory/asthma/en/">seven minutes</a>. </p>
<p>Sport can be a double-edged sword for people with asthma and even in the best of weather exercise can act as a stimulus, narrowing the airways and making it difficult to breathe. Around 80-90% of sufferers <a href="https://books.google.co.uk/books/about/Exercise_Physiology.html?id=XOyjZX0Wxw4C">have exercise-induced asthma</a>, which can trigger symptoms such as coughing, wheezing, tightness of the chest and breathlessness which can be caused by heat and water losses during exercise <a href="http://www.ncbi.nlm.nih.gov/pubmed/3724408">hyperventilation</a> or endless streams of allergens such as pollution and pollen. If symptoms progress and become more severe, it can lead to a full-blown asthma attack where an overproduction of mucus further narrows the airways and limits oxygen intake.</p>
<p>So during May through to August, <a href="http://www.express.co.uk/life-style/health/569182/Asthma-hayfever-hot-weather-pollen-pollution-allergy-sufferers-spring-temperatures">high pollen and pollution levels</a> many are urged to reduce activity levels outdoors and keep their inhalers (normally the reliever) with them.</p>
<p>Yet, as <a href="http://www.asthma.org.uk/knowledge-bank-exercise">Asthma UK</a> points out, eight out of ten people with asthma aren’t doing enough exercise and as we know exercise <a href="http://www.asthma.org.uk/knowledge-bank-living-with-asthma-exercise">has a number of positive effects</a> including helping the heart, bones and digestive system to stay healthy, reducing stress and insomnia, and keeping unwanted weight off. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/86516/original/image-20150626-1405-1gayuv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/86516/original/image-20150626-1405-1gayuv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=548&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86516/original/image-20150626-1405-1gayuv7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=548&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86516/original/image-20150626-1405-1gayuv7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=548&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86516/original/image-20150626-1405-1gayuv7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=689&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86516/original/image-20150626-1405-1gayuv7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=689&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86516/original/image-20150626-1405-1gayuv7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=689&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mark Foster in 2008: has spoken about training with asthma.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Mark_Foster,_October_2008.jpg">Mark Foster/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>Other well-known <a href="http://www.express.co.uk/life-style/health/147501/Swimming-Beneficial-for-asthma">sports asthmatics include</a> swimmers Ian Thorpe, who reportedly took up sport as a way of dealing with his asthma, and Olympian Mark Foster, who has said “swimming can actually help because it teaches you breath control and how to make the most of your lung capacity … we are taught the best way to use all of our lungs not just a small part.” Foster said that in addition to taking a puff of his inhaler before every race, his coaches also kept a careful watch on his lung capacity and peak flow levels. Kvitova <a href="http://www.theaustralian.com.au/sport/tennis/petra-kvitovas-asthma-gets-worse-when-playing-in-us-australia/story-fnbe6xeb-1226554663190">has said</a> that she suffers worse symptoms in certain places and often arrives early before a tournament begins so her lungs can adjust.</p>
<h2>Listening to your body</h2>
<p>Sport can act as a distraction from asthma triggers and a way of ignoring the body. But asthma and sport are both central body experiences, that benefit from listening acutely to breathing patterns. Good breathing technique is fundamental to sport – and used alongside specific training designed to help professional sports people with their asthma, it can improve the experience of asthmatics.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/86515/original/image-20150626-1398-1f0mo00.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86515/original/image-20150626-1398-1f0mo00.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86515/original/image-20150626-1398-1f0mo00.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86515/original/image-20150626-1398-1f0mo00.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86515/original/image-20150626-1398-1f0mo00.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86515/original/image-20150626-1398-1f0mo00.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86515/original/image-20150626-1398-1f0mo00.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Listen in.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=14353142573658728000&search_tracking_id=MvZ81Z2wzGbVw_DM3mzjTw&searchterm=asthma%20runner&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1">Jogging by Shutterstock</a></span>
</figcaption>
</figure>
<p>“Deep listening” is an activity that requires careful, attunement to the nuanced and multiple layers of meaning enmeshed in sound. Asthma includes listening to sounds from the body: noisy heavy breathing, wheezing, coughing, panting, spluttering and sneezing. Some athletes develop acute attunement by identifying very subtle changes in their bodies in an attempt to anticipate and monitor their asthma and breathing. </p>
<p>Not only do athletes develop “deep listening” to their bodies, but “acute attentiveness to and active steadying of respiration, together with conscious efforts to relax and keep calm” <a href="http://www.bloomsbury.com/uk/the-auditory-culture-reader-9781859736180/">is also required</a>. With the benefit of experience and a developed attunement to their bodies’ responses, some sportspeople can learn what to expect during their sporting participation enabling them to feel more in control. </p>
<p>Therefore, many sportspeople can be more aware of their limitations when exercising, more in control of their breathing and know when not to push it to the max to avoid the onset of an asthmatic episode.</p>
<p>In <a href="http://irs.sagepub.com/content/early/2012/11/04/1012690212463918">research we carried out</a>, some sportspeople said that, in general, they “did not listen to their bodies”, which often had later consequences such as a sudden onset of asthma after training or competing, along with feelings of panic and a reliance on an inhaler as a quick fix. </p>
<p>On the other hand, those who said that they “listened deeply” to their bodies, articulated an intelligent form of knowledge about their bodies which meant that while they couldn’t always engage in more activities, they did enjoy the activities in which they were able to participate and asthma seemed to be less disruptive to their daily lives.</p>
<p>Nonetheless, there are limits to the predictability of asthma and there are incidences where there can be an endless stream of potential allergens which takes conscientious efforts, precautionary measure and monitoring of bodily reactions.</p><img src="https://counter.theconversation.com/content/43929/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Owton 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>From Wimbledon champions to Olympic swimmers, asthmatics have reached the top and breathing technique is all important.Helen Owton, Lecturer in Sport & Fitness, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/347662015-01-06T19:23:11Z2015-01-06T19:23:11ZEarly birds: how climate change is shifting time for animals and plants<p>Every Spring, the blanket of Australian alpine snow starts to melt, and the Mountain Pygmy Possum wakes up from its seven-month-long hibernation. </p>
<p>Naturally after so long under the snow, its first thought is to find food. But over the last few years, the <a href="http://aaarjournal.org/doi/abs/10.1657/1938-4246-41.2.212">snow’s been melting earlier</a>, and an important food source – the Bogong moth – is <a href="http://link.springer.com/article/10.1007/s11629-010-1115-2">arriving later</a> on its yearly migration, <a href="http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=267#threats">leaving these endangered possums to go hungry</a>. </p>
<p>In Australia, spring-time events on the land, as well as in freshwater and marine systems are now <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0075514">generally occurring earlier</a> than they used to.</p>
<p>The time at which certain events happen in the lives of animals or plants – such as when moths or birds start their annual migration, or when plants flower – is mostly influenced by temperature, although day length and rainfall can also play a part. </p>
<p>The timing of these life cycle events and their interaction with the seasonal climate is called phenology.</p>
<p>Since phenology is sensitive to small changes in the environment, any changes in timing can help highlight the impact of climate change on natural and managed systems. You can help record these changes through the ClimateWatch app developed by the Bureau of Meteorology, Earth Watch Institute and the University of Melbourne.</p>
<h2>Starting early</h2>
<p>The life cycles of many plants and animals affect our day-to-day lives, and understanding these cycles is important for our survival. To successfully produce food or hunt, we need to understand animal behaviour and plant growth – and how these are linked to the environment.</p>
<p>In Australia, the breeding season and migration of many birds is beginning earlier by an average of <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0075514">2.6 days per decade</a>.</p>
<p>For many Australian plants, flowering, fruiting and harvesting is starting earlier by an <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0075514">average of 9.7 days per decade</a>.</p>
<p>Flowering also means the presence of pollen in the air. What was once thought of as the “pollen season” is also changing as the climate changes.</p>
<p>For many people, airborne pollen is a source of suffering – for asthma sufferers who are allergic to pollen, and for those with hay fever, pollen can mean sneezing and wheezing. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/66929/original/image-20141211-6027-jl584s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/66929/original/image-20141211-6027-jl584s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=368&fit=crop&dpr=1 600w, https://images.theconversation.com/files/66929/original/image-20141211-6027-jl584s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=368&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/66929/original/image-20141211-6027-jl584s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=368&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/66929/original/image-20141211-6027-jl584s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=462&fit=crop&dpr=1 754w, https://images.theconversation.com/files/66929/original/image-20141211-6027-jl584s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=462&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/66929/original/image-20141211-6027-jl584s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=462&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Some people will be less enthused about a longer pollen season.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/brookenovak/437103661">Brooke Novak</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>In <a href="http://www.pnas.org/content/108/10/4248.abstract">North America</a> the length of the ragweed pollen season, one of the biggest causes of hay fever, is now 13-27 days longer than in 1995 (depending on location). The longer pollen season is linked to recent warming, delays in the first frost of Autumn, as well as the number of frost-free Autumn days. </p>
<p>Similar changes have also been found in Europe. Researchers in <a href="http://www.annallergy.org/article/S1081-1206%2809%2900119-7/abstract">Italy</a> found that the pollen season for several allergenic plants was up to 85 days longer in recent decades, with the pollen season starting earlier now than in the 1980s.</p>
<p><a href="http://www.nature.com/nclimate/journal/v2/n4/full/nclimate1417.html">Wine grapes</a> in southern Australia are also maturing earlier – on average eight days earlier per decade than they were in 1985. These changes are related to increasing air temperatures and decreasing moisture in the soil. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/66927/original/image-20141211-6030-17vzwjw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/66927/original/image-20141211-6030-17vzwjw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/66927/original/image-20141211-6030-17vzwjw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/66927/original/image-20141211-6030-17vzwjw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/66927/original/image-20141211-6030-17vzwjw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/66927/original/image-20141211-6030-17vzwjw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/66927/original/image-20141211-6030-17vzwjw.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">Wine grapes are now maturing earlier than they used to, thanks to climate change.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/werkman/7376268882">Peter Werkman – www.peterwerkman.nl</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The grape growing season is likely to shorten which will mean changes to the areas suitable for particular varieties. At least <a href="http://www.theage.com.au/business/climate-drives-big-wine-deal-20100816-1272s.htm">one winery</a> has already bought vineyards in Tasmania as a way of dealing with a warming climate.</p>
<h2>A Northern Hemisphere bias</h2>
<p>Most of the reports of changes in species phenology have come from the Northern Hemisphere. This may be partly due to the dramatically visible seasonal changes over this region (first snow for example). </p>
<p>“Firsts” in these regions, such as the arrival of migratory birds or flowering, are very obvious and easy to record. </p>
<p>Some phenological events are also documented because of cultural significance. In Japan, the date of the first bloom of <a href="http://link.springer.com/article/10.1007/s00484-009-0272-x#">cherry blossoms</a> is known from as far back as the ninth century. </p>
<h2>Changing species relationships</h2>
<p>Box-ironbark forests are unusual in that they have trees which flower during winter. These flowers are a vital food source for nectar-dependent woodland birds. </p>
<p>Occasionally, these ironbarks fail to flower, leaving dependent woodland birds short of a vital food supply. </p>
<p><a href="http://link.springer.com/article/10.1007/s10666-006-9063-5">Historical records</a> from 1945 to 1970 of red ironbark flowering in the Rushworth Forest in Victoria, indicate that no flowering occurred in only four of the 26 years. </p>
<p>However, a more <a href="http://onlinelibrary.wiley.com/doi/10.1111/ddi.12230/abstract">recent study</a> from 1997 to 2007 of red ironbark flowering found that the number of years with no flowering had increased. Over the 11-year study, there were four years with no flowering, with three of the failures occurring in the final six years. These flowering failures may have contributed to recent declines in the number of woodland birds in that forest.</p>
<p>Despite these snapshots, an Australia-wide understanding of the impacts of climate change is needed, including records of phenology from many more regions. </p>
<p>A new app means you can now contribute to recording species phenology in Australia. The Bureau of Meteorology, Earth Watch Institute and the University of Melbourne have developed <a href="http://www.climatewatch.org.au/">ClimateWatch</a>, where you can record the life cycle events of plants and birds, spiders and whales and more.</p><img src="https://counter.theconversation.com/content/34766/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marie Keatley has received funding from ARCNESS, Australian Government and the Dahl Trust. She is a founding partner of ClimateWatch and a member of its Steering Committee.</span></em></p><p class="fine-print"><em><span>Lynda Chambers is a founding partner of ClimateWatch and a member of its Steering Committee.</span></em></p><p class="fine-print"><em><span>Paul Beggs receives funding from New South Wales (NSW) Environmental Trust (NSW Government), and is a member of the Australian Aerobiology Working Group which was supported by the Australian Centre for Ecological Analysis and Synthesis and co-sponsored by untied funds from Merck Sharp and Dohme.</span></em></p>Every Spring, the blanket of Australian alpine snow starts to melt, and the Mountain Pygmy Possum wakes up from its seven-month-long hibernation. Naturally after so long under the snow, its first thought…Marie Keatley, Adjunct Associate, Department of Forest and Ecosystem Science, The University of MelbourneLynda Chambers, Principal Research Scientist at the Centre for Australian Weather and Climate Research, Australian Bureau of MeteorologyPaul Beggs, Environmental Health Scientist, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/181002013-10-01T20:36:41Z2013-10-01T20:36:41ZPollen counting is not something to be sneezed at<figure><img src="https://images.theconversation.com/files/32248/original/hfm8t67s-1380607866.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Hay fever affects one in six Australians.</span> <span class="attribution"><span class="source">Ed Newbigin</span></span></figcaption></figure><p>Ah, spring, the sun shines again, the birds sing and - ach-hoo! Airborne grass pollens trigger bouts of hay fever and episodes of asthma in people with pollen allergies.</p>
<p>But there is a way we could mitigate the impact of the season - pollen counts. These work in the same way as summer <a href="http://www.bom.gov.au/uv/">UV alerts</a>, by telling us when there’s enough of something around to cause health harms. </p>
<p>And this helps manage the impact of UV or pollen by giving us time to prepare, by wearing UV protection, for instance, or taking antihistamines. But while this sounds like a good idea, most places in Australia don’t have a pollen count, so those of us with allergies are left to our own devices.</p>
<h2>Pollen and health</h2>
<p>Let’s talk first about how pollen affects health. Hay fever is the most obvious example. </p>
<p>According to the <a href="http://www.abs.gov.au/AUSSTATS/abs@.nsf/0/9B34B8C8BF2FDA34CA25773700169C83?opendocument">2007–08 National Health Survey</a>, hay fever affects one in six Australians, severely impairing their quality of life by making sleep difficult and causing them to under-perform at work or school. </p>
<p>Hay fever is strongly associated with asthma; more than 80% of allergic asthmatics also have hay fever. Asthma costs the Australian community over $700 million annually and this impact has made it one of the country’s <a href="http://www.aihw.gov.au/national-health-priority-areas">national health priorities</a>.</p>
<p>Asthma and hay fever are caused by our immune systems responding inappropriately to substances in the environment that are not harmful. These are known as triggers. </p>
<p>Hay fever triggers cause the lining of the eyes, nose and throat to become inflamed, producing the typical symptoms of sneezing, itchy eyes and a runny nose. Asthma triggers cause the lining of the small airways of the lung to swell, making it harder to breath.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/32251/original/5dh7kv3n-1380609655.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/32251/original/5dh7kv3n-1380609655.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/32251/original/5dh7kv3n-1380609655.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/32251/original/5dh7kv3n-1380609655.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/32251/original/5dh7kv3n-1380609655.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/32251/original/5dh7kv3n-1380609655.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/32251/original/5dh7kv3n-1380609655.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">Asthma triggers cause the lining of the small airways of the lung to swell, making it harder to breath.</span>
<span class="attribution"><span class="source">Rod Begbie</span></span>
</figcaption>
</figure>
<h2>Free like the wind</h2>
<p>Pollen from certain wind-pollinated plants is the main asthma and hay fever trigger in the outdoor environment. The plants in question use wind to transport their pollen between plants, rather than relying on insects and birds. </p>
<p>Because they don’t need to attract animals, the flowers of wind-pollinated plants are rather dull in comparison to the bright, showy flowers of animal-pollinated plants. </p>
<p>But what they lack in colour, wind-pollinated plants more than make up for with prodigious pollen production. A single plant can release untold millions of pollen grains into the air. </p>
<p>While Australia’s native plants are generally not wind-pollinated, many introduced plants are. These include trees from the northern hemisphere commonly found in gardens and along suburban roads, such as birch, elm, and ash. </p>
<p>But the worst plants by far for pollen allergies are grasses. Perennial ryegrass is a valuable pasture grass planted across vast areas of southern Australia. By sheer weight of numbers perennial ryegrass pollen is Australia’s number one outdoor allergy trigger.</p>
<p>Flowering of perennial ryegrass across much of southern Australia peaks in November. And it’s no coincidence this is also the peak time for sales of the oral antihistamines.</p>
<h2>Knowledge network</h2>
<p><a href="http://www.bbc.co.uk/news/health-17944765">Pollen counting</a> can tell us how much grass pollen is in the air on a particular day. By combining this information with the weather forecast, we can predict grass pollen levels for the next few days. </p>
<p>Knowing the grass pollen forecast can help people allergic to grass pollen plan ahead. But before you can forecast pollen levels for a particular place, you need to have a few seasons’ worth of counts under your belt so you know how weather patterns affect pollen levels locally. </p>
<p>Unfortunately, Australia has very few pollen counting stations and most operate only sporadically. The lonely exception is <a href="http://www.melbournepollen.com.au/">Melbourne’s pollen count</a>, which has been running consistently for over 20 years.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/32246/original/6dyr3r6q-1380607778.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/32246/original/6dyr3r6q-1380607778.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/32246/original/6dyr3r6q-1380607778.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/32246/original/6dyr3r6q-1380607778.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/32246/original/6dyr3r6q-1380607778.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/32246/original/6dyr3r6q-1380607778.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/32246/original/6dyr3r6q-1380607778.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">Perennial ryegrass pollen is Australia’s number one outdoor allergy trigger.</span>
<span class="attribution"><span class="source">Arthur Chapman</span></span>
</figcaption>
</figure>
<p>This makes a stark contrast with <a href="http://www.polleninfo.org/en/laenderauswahl.html">Europe</a>, where a network of more than 600 pollen counting stations operates throughout the northern allergy season. That’s from early spring, when the trees flower, through to early autumn when weeds, such as dock and mugwort, flower. </p>
<p>The network operates efficiently across several countries and languages. And a similarly large network of stations operates across <a href="http://www.aaaai.org/global/nab-pollen-counts.aspx">North America</a>.</p>
<p>Australia’s lack of a pollen count network is surprising and means we often guess at things we really should know. For instance, we suspect Australia’s allergy season will be relatively simple to track compared to Europe’s, as we mainly have to contend with grass pollen. </p>
<p>But subtropical grasses that flower in summer are abundant in northern parts of Australia adding to the burden of hay fever. Right now, we don’t have a way of quantifying their role in the hay fever and asthma experienced by the population.</p>
<h2>Knowledge and the power to help</h2>
<p>Melbourne’s pollen data has been vital for understanding how grass pollen in the air influences <a href="http://www.ncbi.nlm.nih.gov/pubmed/22515396">hospital admissions</a> for asthma. It seems ridiculous that we don’t know this for all Australian cities.</p>
<p>Not only do we need a network to monitor pollen, we need to be able to link it with weather forecasts for it to become a predictive tool.</p>
<p>On November 25, 2010, Melbourne’s ambulance service was overwhelmed with a massive number of calls from people with acute respiratory problems because of thunderstorm asthma.</p>
<p><a href="http://theconversation.com/explainer-what-is-thunderstorm-asthma-4159">Thunderstorm asthma</a> occurs when there’s a thunderstorm during a high pollen count period. Prediction of pollen-induced epidemics of thunderstorm asthma could help hospital emergency departments prepare for such events. </p>
<p>This is only one of the many ways a national pollen count network could help improve public health throughout Australia. We just need to join the rest of the developed world and start gathering data that can inform us about what to do.</p><img src="https://counter.theconversation.com/content/18100/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ed Newbigin has received funding for pollen counting from the NHMRC.</span></em></p><p class="fine-print"><em><span>Janet Davies is funded by an Australian National Health and Medical Research Council Development grant. She is the Principal Investigator of an Australian Centre for Ecological Analysis and Synthesis Working Group on Australasian Aerobiology, which is co-sponsored by Merck Sharpe and Dohme.
Janet Davies is an inventor on two patent applications for improving diagnosis and treatment of subtropical grass pollen allergy. She has received consultancies and collaborative research funds from Stallergenes.</span></em></p>Ah, spring, the sun shines again, the birds sing and - ach-hoo! Airborne grass pollens trigger bouts of hay fever and episodes of asthma in people with pollen allergies. But there is a way we could mitigate…Ed Newbigin, Associate Professor of Botany, The University of MelbourneJanet Davies, Senior Research Fellow, Lung and Allergy Research Centre, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/141872013-05-17T05:52:27Z2013-05-17T05:52:27ZThe pollen forecast is in: a good June could be a bad year for grass<figure><img src="https://images.theconversation.com/files/23765/original/gbrvn8y3-1368544491.jpg?ixlib=rb-1.1.0&rect=6%2C6%2C4157%2C2644&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If we have good weather in June the grass pollen count could be severe.</span> <span class="attribution"><span class="source">PA</span></span></figcaption></figure><p>When I was a child and was first diagnosed with hay fever, the doctor told me I would grow out of it. I didn’t ask for a rough date when that might be – I just went away and each year I suffered I hoped it would be the last. When I reached 20, it was still as bad as ever, as it was in my 30s and 40s. It’s mid-May and the grass pollen season is poised ready to start. I won’t be holding my breath.</p>
<p>As a pollen forecaster, I frequently meet hay fever sufferers who tell me they have “grown into it”. Hay fever can come along at any age although it mostly affects people who have a genetic predisposition towards it. </p>
<p>It can also affect people in different ways. For example, I’m affected by the earlier-flowering grasses and my symptoms tend to subside by late June, whereas a previous colleague didn’t get symptoms until late June. My younger sister is mildly affected whereas I get it quite badly. Some people are only affected at very high counts, others sneeze at just a few grains.</p>
<p>Hayfever is caused by pollen entering the nose and triggering a reaction in the mast cells causing them to release high amounts of histamine in an attempt to repel the invaders. The histamine release causes a raft of symptoms, including excessive sneezing, a runny nose, blocked sinuses, itchy palate, irritability and watery, itchy and inflamed eyes.</p>
<p>Not all pollen types cause an allergy. The worst offenders are a suite of tree pollens (hazel, alder, birch, plane and oak), grass pollen and a few weed pollens (nettle, dock, mugwort and plantain). All of these are pollinated by the wind and therefore become airborne in high amounts as they are dispersed between plants. </p>
<p>Grass pollen is the worst, affecting around 95% of hay fever sufferers. A pollen count of just <a href="http://www.worcester.ac.uk/discover/recording-the-pollen-count.html">50 grass grains per cubic metre of air is sufficient</a> is sufficient to trigger symptoms in all patients. </p>
<p>Flowers are often blamed for hay fever but these are largely insect-pollinated and the heavy, sticky pollen is unlikely to be breathed in.</p>
<p>The grass pollen season can start in April with several early-flowering types. This year, the grass pollen season is off to a late start due to the cold weather up to mid-April, but it will catch up and already a few grass species are in flower. The lawn grass (Poa annua) is flowering widely and abundantly this year, suggesting that the main season types will also. The main grass pollen season starts in late May and the first high count usually occurs in early June. So, what will this year’s season bring us?</p>
<p>Since the mid-nineties, pollen levels have been on the increase. Even in the predominantly cool, wet summers of the last six years, the total grass pollen catch has been average rather than low. We can assume this trend will continue this year and that, if the weather is good in June, we will have a severe season or at least an average one if it’s not.</p>
<p>There have been peaks and troughs in grass pollen since records began 60 years ago. Largely, the trends have followed the amount of grassland area. However, looking at the records for grassland cover reveals little change since the mid-nineties, suggesting that other factors have become more important. </p>
<p>So, what could these be? It is already well-established that climate change is affecting many plants in various ways. In the case of grasses it seems that warmer, wetter spring weather favours growth and allows them to produce more pollen. In addition, a number of researchers have examined the effects of <a href="http://www.ncbi.nlm.nih.gov/pubmed/22104602">higher CO2 levels on pollen production</a> and found increases in some circumstances.</p>
<p>Researchers at the National Pollen and Aerobiology Research Unit, along with associates in Europe, have been looking at the amount of allergen that gets airborne. Pollen grains contain proteins and it is these that are the allergens that trigger symptoms. The research shows that sometimes the <a href="http://www.sciencedirect.com/science/article/pii/S1352231012000751">allergen amounts can be much higher than the actual pollen count</a>. Further work will be conducted to determine why this occurs and whether or not the pollen grains are producing more proteins per grain – in other words, whether they are becoming more allergenic.</p><img src="https://counter.theconversation.com/content/14187/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>There are no conflicts of interest related to this document.</span></em></p>When I was a child and was first diagnosed with hay fever, the doctor told me I would grow out of it. I didn’t ask for a rough date when that might be – I just went away and each year I suffered I hoped…Beverley Adams-Groom, Chief Palynologist, University of WorcesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/43302011-12-04T19:37:01Z2011-12-04T19:37:01ZAchew! It’s hayfever season again<figure><img src="https://images.theconversation.com/files/6090/original/7cb0bcb1622d4431-1322786967.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Seasonal allergic rhinoconjunctivitis (or pollinosis in Europe) is one of the most common chronic respiratory conditions seen in medical practice.</span> <span class="attribution"><span class="source">Marco Raaphorst</span></span></figcaption></figure><p>Spring and summer are accompanied for many with the much less welcome start of another bout of “hayfever”. A term originating in England, “hayfever” arose out of the popular belief that the ailment was caused by some invisible emanation from new hay.</p>
<p>Today, seasonal allergic rhinoconjunctivitis (or pollinosis in Europe) is one of the most common chronic respiratory conditions seen in medical practice. </p>
<p>According to a recent <a href="http://www.aihw.gov.au/">Australian Institute of Health & Welfare (AIHW)</a> report, around <a href="http://aihw.gov.au/publication-detail/?id=10737420595">15% of Australians or 3.1 million people</a> report suffering from the condition. And the amount of money paid by community pharmacies to wholesalers for medications commonly used to treat allergic rhinitis doubled between 2001 ($107.8 million) and 2010 ($226.8 million). </p>
<h2>Whence the symptoms?</h2>
<p>Symptoms of allergic rhinoconjunctivitis are caused by an allergic reaction resulting in inflammation of the nasal lining. This leads to other consequences.</p>
<p>The first step in an allergic reaction is the development of sensitisation. Repeated exposure to an allergen in a genetically predisposed individual leads to the formation of an allergic antibody (IgE) response to that particular allergen. Once sensitised, exposure to small amounts of the allergen can cause a rapid response, leading to the development of a range of symptoms. </p>
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<img alt="" src="https://images.theconversation.com/files/6096/original/33a681b45240f757-1322790352.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/6096/original/33a681b45240f757-1322790352.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6096/original/33a681b45240f757-1322790352.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6096/original/33a681b45240f757-1322790352.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6096/original/33a681b45240f757-1322790352.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6096/original/33a681b45240f757-1322790352.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6096/original/33a681b45240f757-1322790352.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&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="attribution"><span class="source">Maggie</span></span>
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<p>Typical symptoms include itching of the nose, ears, palate, repeated sneezing, watery nasal discharge, nasal congestion or blockage, and, for many, these symptoms are accompanied by itchy, watery, red eyes.</p>
<h2>Blame the plants</h2>
<p>At this time of the year, the most common trigger for allergic rhinoconjunctivitis is pollen exposure. Pollen is the male gamete produced by all flowering plants to fertilise the female part of the flower. </p>
<p>Many factors affect the pollen load in the air: time of year, density of plant species, temperature, rainfall, humidity, wind and its direction, and hours of sunlight. Most hayfever sufferers are sensitive to many different pollen species but wind-pollinated plants, such as grasses, are the most significant triggers. </p>
<p>People often blame more obvious plants, such as wattle or Plane trees, for their reaction but these aren’t the most common causes of allergic rhinoconjunctivitis.</p>
<h2>Misunderstood burden</h2>
<p>The symptoms of allergic rhinoconjunctivitis are very annoying to those who suffer them but the true burden of this condition is often underestimated. </p>
<p>We classify severity of allergic rhinoconjunctivitis as mild or moderate/severe. With mild allergic rhinitis, there’s no impairment of sleep, daily activities, leisure or sport, and school or work. That’s because while symptoms are present, they aren’t troublesome. </p>
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<img alt="" src="https://images.theconversation.com/files/6094/original/eb6bf998821da511-1322789750.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/6094/original/eb6bf998821da511-1322789750.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6094/original/eb6bf998821da511-1322789750.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6094/original/eb6bf998821da511-1322789750.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6094/original/eb6bf998821da511-1322789750.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6094/original/eb6bf998821da511-1322789750.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6094/original/eb6bf998821da511-1322789750.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">
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<span class="attribution"><span class="source">Christian Guthier</span></span>
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<p>With moderate/severe allergic rhinoconjunctivitis, there may be impairment of sleep, daily activities, leisure or sport and impairment of school or work. Since this level of impairment occurs at peak exam time for many teenagers and young adults, there’s clearly potential for significant interference with life.</p>
<h2>Hayfever companions</h2>
<p>Allergic rhinoconjunctivitis is associated with a number of other chronic conditions (co-morbidities), the most important of which is asthma. These two conditions share common genetic factors and triggers. About four out of five people with asthma have rhinitis and between 15% and 30% of rhinitis patients have asthma. </p>
<p>Other associated conditions include middle ear infection, sinusitis and sleep apnoea. </p>
<p>There’s no cure for allergic rhinitis so effective management is the best available approach and the goal is to achieve optimal symptom control. Patients who seek advice and guidance from their GP or specialist have a better outcome with management than those who continually self medicate.</p>
<h2>Other therapies</h2>
<p>Therapeutic options include allergen avoidance, pharmacotherapy (such as intranasal corticosteroids and antihistamines), non-medicated treatments (such as saline douches or sprays) and immunotherapy, either injection or sublingual therapy. </p>
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<img alt="" src="https://images.theconversation.com/files/6095/original/c2e9ba848228e199-1322790253.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/6095/original/c2e9ba848228e199-1322790253.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=405&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6095/original/c2e9ba848228e199-1322790253.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=405&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6095/original/c2e9ba848228e199-1322790253.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=405&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6095/original/c2e9ba848228e199-1322790253.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=510&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6095/original/c2e9ba848228e199-1322790253.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=510&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6095/original/c2e9ba848228e199-1322790253.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=510&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="attribution"><span class="source">Duncan Harris</span></span>
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</figure>
<p>Patients are always interested in ways of avoiding their triggers but where pollen is concerned, truly useful avoidance strategies are limited. You can stay indoors with air conditioning and filtration systems in place, but this isn’t very practical advice. </p>
<p>Certainly wearing sunglasses and a hat while outdoors may minimise the eye symptoms as pollen grains won’t be able to come into contact with the membrane that covers the eye and lines the inside of the eyelids (conjunctiva). </p>
<h2>Over-the-counter meds</h2>
<p>Many “hayfever treatments” are available over the counter at the pharmacy so most people try these before seeking help. Antihistamines may address some of the symptoms associated with the condition – they can relieve itching, sneezing and the runny nose – but are less effective at clearing nasal blockage. </p>
<p>Ideally only non-sedating antihistamines should be used because even though they’re cheaper, other types may have a negative impact on performance and concentration. But antihistamines only treat the symptoms, not addressing the underlying allergic inflammation that’s the basis of the problem.</p>
<p>Ideal management involves using a treatment that’ll reduce allergic inflammation and have a greater lasting effect on all aspects of the condition. Intranasal corticosteroids fulfil this role, with the newer agents having an excellent safety profile. They’re preventative medication and ideally should be used from the onset of the pollen season to ensure maximum benefit. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/6091/original/38bb9982ce8dcbf3-1322787022.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/6091/original/38bb9982ce8dcbf3-1322787022.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/6091/original/38bb9982ce8dcbf3-1322787022.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/6091/original/38bb9982ce8dcbf3-1322787022.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/6091/original/38bb9982ce8dcbf3-1322787022.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=525&fit=crop&dpr=1 754w, https://images.theconversation.com/files/6091/original/38bb9982ce8dcbf3-1322787022.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=525&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/6091/original/38bb9982ce8dcbf3-1322787022.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=525&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="attribution"><span class="source">Timo Kirkkala</span></span>
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<p>Compliance with correct use may be a problem so seeking medical advice and understanding the way they work and their safety profile, will lead to better outcomes.</p>
<h2>Oldie but goodie</h2>
<p>Immunotherapy is a very old therapy. In fact, this type of treatment celebrates a 100 years of use this year! Following decades of active research, we have a much better understanding of how immunotherapy brings about reduction in allergic inflammation and leads to long-term benefit for people with allergic rhinoconjunctivitis. </p>
<p>This is a long-term treatment requiring dedication, compliance and some expense so it must be prescribed by a specialist who’ll advise on suitability and provide the vaccine prescription.</p>
<p>Seasonal allergic rhinoconjunctivitis is usually a long-lived condition once it’s triggered, affecting older children, teenagers and adults, sometimes for decades. It causes significant impairment of quality of life and is often associated with other conditions. </p>
<p>Although there’s no cure at present, it can be successfully managed so seek advice from your GP and in some instances, from an allergy specialist, so that the management strategy that’s best for your condition may be formulated.</p><img src="https://counter.theconversation.com/content/4330/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Connie Katelaris 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>Spring and summer are accompanied for many with the much less welcome start of another bout of “hayfever”. A term originating in England, “hayfever” arose out of the popular belief that the ailment was…Connie Katelaris, Professor of Immunology and Allergy, UWAS & Head of Unit, South Western Sydney Local Health DistrictLicensed as Creative Commons – attribution, no derivatives.