tag:theconversation.com,2011:/ca/topics/thunderstorm-asthma-7389/articlesThunderstorm asthma – The Conversation2023-10-30T06:08:22Ztag:theconversation.com,2011:article/2157932023-10-30T06:08:22Z2023-10-30T06:08:22ZWe could see thunderstorm asthma in south-eastern Australia this season – here’s how to prepare<figure><img src="https://images.theconversation.com/files/556014/original/file-20231026-21-hqekmc.jpg?ixlib=rb-1.1.0&rect=8%2C0%2C5982%2C3997&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/lighting-strikes-over-melbourne-victoria-2278570109">Ruben Fino/Shutterstock</a></span></figcaption></figure><p>Victorians <a href="https://www.9news.com.au/national/victorians-warned-to-prepare-for-thunderstorm-asthma-season/e4fc9389-32d6-4bfc-a105-8e9d450d9097">have been warned</a> to prepare for the possibility of thunderstorm asthma again this season. </p>
<p>In temperate regions of Australia, thunderstorm asthma occurs when levels of grass pollen in the air are high, and when thunderstorm fronts pass over grass pollen sources. The weather conditions we see with a thunderstorm, including stormy winds and moisture, can break up pollen into particles small enough to enter the airways. </p>
<p>Thunderstorm asthma events have been noted all over the world, but the most severe ever reported was <a href="https://pubmed.ncbi.nlm.nih.gov/29880157/">in Melbourne on November 21, 2016</a>. In one night almost 3,500 people sought emergency care and ten people died.</p>
<p>While we don’t have reason to expect we’ll see another emergency at this scale, a longer than usual <a href="https://www.canberratimes.com.au/story/8382447/long-pollen-season-prompts-thunderstorm-asthma-warning/">grass pollen season</a> suggests a risk of thunderstorm asthma in southern Australia this year. </p>
<p>At the time of writing, on <a href="https://www.miragenews.com/high-thunderstorm-asthma-forecast-for-west-1113262/">Monday October 30</a>, west and south Gippsland was classified as being <a href="https://www.melbournepollen.com.au/">at high risk</a> of thunderstorm asthma. </p>
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<p>So who is at highest risk, and what’s the best way to prepare?</p>
<h2>A changing climate</h2>
<p>In Australia, most thunderstorm asthma events have occurred during <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0194929">the peak grass pollen season</a> from the end of October through to early December. </p>
<p>With climate change we’re seeing significant increases in <a href="https://www.frontiersin.org/articles/10.3389/falgy.2021.705313/full">seasonal loads of airborne grass pollen</a>. Pollen production depends partly on rainfall. Rain preceding the pollen season generally makes grasses grow more, driving up airborne <a href="https://www.sciencedirect.com/science/article/pii/S0013935122010891">grass pollen levels</a> over the season. </p>
<p>Despite this El Niño year, <a href="http://www.bom.gov.au/climate/enso/">when rainfall is typically lower</a>, paradoxically, grass pollen levels in <a href="https://www.canberrapollen.com.au/news-events/how-grass-pollen-season-going-canberra/">Canberra</a> have been high early in the season. </p>
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Read more:
<a href="https://theconversation.com/pollen-does-more-than-make-you-sneeze-it-can-cause-thunderstorm-asthma-even-if-youre-not-asthmatic-190235">Pollen does more than make you sneeze. It can cause thunderstorm asthma, even if you're not asthmatic</a>
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<p>With <a href="https://www.sciencedirect.com/science/article/pii/S0034425722000979?via%3Dihub#f0005">shifts over time in the distribution</a> of the sorts of grasses that flower in cool season (temperate) and those that flower in warmer season (subtropical), grass pollen seasons may continue to change, potentially extending the timing and magnifying exposure.</p>
<p>However, these patterns aren’t necessarily predictable, so we need long-term, year-round pollen monitoring to track ongoing changes in Australian grass pollen seasons.</p>
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<img alt="Grass in a meadow." src="https://images.theconversation.com/files/556015/original/file-20231026-24-hqekmc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556015/original/file-20231026-24-hqekmc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556015/original/file-20231026-24-hqekmc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556015/original/file-20231026-24-hqekmc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556015/original/file-20231026-24-hqekmc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556015/original/file-20231026-24-hqekmc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556015/original/file-20231026-24-hqekmc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Grass pollen can trigger thunderstorm asthma.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/blooming-grass-summer-meadow-macro-pollen-2314006571">Fire-n/Shutterstock</a></span>
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<h2>Who is most at risk?</h2>
<p>The <a href="https://www.sciencedirect.com/science/article/pii/S0954611117303517?via%3Dihub">main risk factor for thunderstorm asthma</a> is hay fever, a condition usually due to grass pollen allergy. Hay fever is common, affecting as many as <a href="https://www.aihw.gov.au/reports/chronic-respiratory-conditions/allergic-rhinitis-hay-fever/contents/allergic-rhinitis">one in five people</a> in Australia and causing symptoms including an itchy, runny and blocked nose and itchy eyes over the course of the pollen season. </p>
<p>Asthma is more common in people with hay fever and its symptoms include cough, wheeze, chest tightness and shortness of breath. Symptoms of <a href="https://asthma.org.au/triggers/thunderstorm-asthma/">thunderstorm asthma</a> are the same as for other asthma attacks.</p>
<p>However, many people who develop thunderstorm asthma won’t have <a href="https://www.sciencedirect.com/science/article/pii/S0954611117303517?via%3Dihub">had asthma before</a>.</p>
<p>That said, people with asthma and hay fever are at higher risk of thunderstorm asthma, particularly if they’re not taking asthma preventer medication regularly. </p>
<p>Our research indicates that people with hay fever with <a href="https://www.jacionline.org/article/S0091-6749(21)01689-4/fulltext">high levels of allergic antibodies</a> (allergen-specific IgE) to ryegrass pollen, one of the most common temperate grasses in the southern regions of Australia, are particularly at risk of thunderstorm asthma.</p>
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Read more:
<a href="https://theconversation.com/its-not-just-about-melbourne-why-we-need-a-national-approach-to-thunderstorm-asthma-69426">It's not just about Melbourne: why we need a national approach to 'thunderstorm asthma'</a>
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<h2>How to prepare</h2>
<p>People who are affected by hay fever, asthma or both should be particularly vigilant for thunderstorm asthma warnings.</p>
<p>Thunderstorm asthma alerts are available from the <a href="https://www.health.vic.gov.au/environmental-health/epidemic-thunderstorm-asthma-risk-forecast">Victorian Department of Health</a> or the <a href="https://www.melbournepollen.com.au/">Melbourne Pollen Count and Forecast</a>, and you can register for alerts <a href="https://www.health.nsw.gov.au/environment/factsheets/Pages/thunderstorm-asthma.aspx">in the Wagga Wagga region</a> in New South Wales. Local grass pollen information is also available for <a href="https://auspollen.edu.au/brisbane/">Brisbane</a>, <a href="https://www.melbournepollen.com.au/">Perth</a>, <a href="https://www.canberrapollen.com.au/">Canberra</a> and <a href="https://www.sydneypollen.com.au/">Sydney</a>. </p>
<p>If faced with a thunderstorm asthma warning, the first thing to do if you think you may be susceptible is to stay out of the weather. Remain indoors with the doors and windows closed, particularly during the windy period that precedes the actual storm. Don’t use air conditioners that bring air in from outside. </p>
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<img alt="A man sitting on a couch at home using an inhaler." src="https://images.theconversation.com/files/556016/original/file-20231026-27-39d2cn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556016/original/file-20231026-27-39d2cn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556016/original/file-20231026-27-39d2cn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556016/original/file-20231026-27-39d2cn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556016/original/file-20231026-27-39d2cn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556016/original/file-20231026-27-39d2cn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556016/original/file-20231026-27-39d2cn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The symptoms of thunderstorm asthma are generally the same as regular asthma.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-asthma-asian-home-sitting-on-2132727539">voronaman/Shutterstock</a></span>
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<p>The second thing – and you don’t need to wait for a warning to do this – is to ensure you have a plan to prevent and manage symptoms. This is something you can work out during a visit with your GP.</p>
<p>People with asthma should have a management plan which will usually include a prescribed preventer inhaler. It’s important to take preventer medications regularly as prescribed (even if you’re feeling well) and have reliever medication available at all times. </p>
<p>If you have <a href="https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis">hay fever</a>, it’s similarly important to keep it well-managed. Regular use of a nasal steroid spray can help control underlying allergy processes.</p>
<p>Having a plan and treatment on hand is especially important for people who suffer from both hay fever and asthma.</p>
<p>Knowing the steps of asthma first aid and <a href="https://asthma.org.au/treatment-diagnosis/asthma-first-aid/">how to manage an asthma attack</a> is also important for patients and families. People experiencing severe symptoms such as difficulty breathing should call an ambulance or attend the nearest emergency department.</p>
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Read more:
<a href="https://theconversation.com/3-ways-to-prepare-for-bushfire-season-if-you-have-asthma-or-another-lung-condition-214065">3 ways to prepare for bushfire season if you have asthma or another lung condition</a>
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<p>On a broader scale, we need sustained, standardised pollen monitoring, forecasting and reporting at daily and seasonal time scales across Australia to document and predict changes in airborne pollen loads. </p>
<p>Currently, only Victoria has <a href="https://www.health.vic.gov.au/environmental-health/epidemic-thunderstorm-asthma-risk-forecast">a supported thunderstorm asthma warning system</a> in place. But New South Wales has also experienced <a href="https://erj.ersjournals.com/content/16/1/3">thunderstorm asthma events</a>, and outside of temperate regions, grass pollen exposure is associated with increased asthma presentations. A thunderstorm asthma event can overwhelm health-care resources, supporting the need for widespread pollen monitoring and alerts.</p><img src="https://counter.theconversation.com/content/215793/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janet Davies receives funding from the Australian Research Council (DP210100347; LP190100216) and the Department of Health and Aging for the National Allergy Centre of Excellence, and has received grants in the last five years from the National Foundation of Medical Research Innovation, Abionic SA Switzerland, NHMRC (GNT1116107), with co-contributions from Asthma Australia and Stallergenes Greer Australia Pty Ltd, and in kind support from Australian Society for Clinical Immunology and Allergy, Asthma Australia, Bureau of Meteorology, Commonwealth Scientific and Industrial Research Organisation, Stallergenes Greer Australia Pty Ltd, and Federal Office of Meteorology and Climatology MeteoSwiss, ARC (DP190100376; DP170101630), and Queensland Chief Scientist Citizen Science Grant. QUT owns relevant patents US PTO 14/311944 and AU2008/316301 issued. </span></em></p><p class="fine-print"><em><span>Jo Douglass has received funding from the MRFF to support research in Thunderstorm Asthma. She is employed as Director of Research at the Royal Melbourne Hospital and is Head, Department of Medicine at the University of Melbourne. In the past 5 years, she has received honoraria for educational presentations from Astra-Zeneca, GSK, Novartis & CSL. She has served on advisory boards for Sanofi-Aventis, Novartis, GSK, Astra-Zeneca, Immunosis and CSL. She has undertaken contracted or investigator-initiated research on behalf of: GSK, Novartis, Immunosis, AstraZeneca, Sanofi-Aventis, Grifols, CSL, BioCryst & Equilium. She has a personal shareholding in CSL in her superannuation. She is affiliated with the National Allergy Centre of Excellence. </span></em></p><p class="fine-print"><em><span>Joy Lee has received funding from Centre of Research Excellence in Treatable traits, Sanofi and GSK for presenting at educational meetings and travel grants. She is affiliated with the National Allergy Centre of Excellence.</span></em></p>If you’ve got hay fever, or asthma, or both, it’s important to make sure they’re well managed.Janet Davies, Respiratory Allergy Stream Co-chair, National Allergy Centre of Excellence; Professor and Head, Allergy Research Group, Queensland University of TechnologyJo Douglass, Respiratory Allergy Stream Co-chair, National Allergy Centre of Excellence; Professor of Medicine, The University of MelbourneJoy Lee, Respiratory Allergy Stream member, National Allergy Centre of Excellence; Associate Professor, School of Public Health and Preventive Medicine, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2076662023-06-15T10:48:53Z2023-06-15T10:48:53ZWhy hay fever is so bad in the UK right now – and why thunderstorms make things worse for people with allergies and asthma<figure><img src="https://images.theconversation.com/files/531957/original/file-20230614-19-clcfua.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C7688%2C5121&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-allergy-infection-sneezing-shot-young-2157486261">Dragana Gordic/Shutterstock</a></span></figcaption></figure><p>The UK is in the grip of a particularly bad period for hay fever, with people across the nation experiencing a relentless onslaught of sneezing, itchy eyes and nasal congestion. Visits to the <a href="https://www.nhs.uk/conditions/hay-fever/">NHS hay fever advice page</a> have <a href="https://www.england.nhs.uk/2023/06/weekly-visits-to-nhs-websites-hay-fever-advice-reach-122000-as-pollen-levels-rise/">increased by 252%</a> since the beginning of May, signifying the magnitude of the problem.</p>
<p>This <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9993206/">common seasonal affliction</a> is a hypersensitive reaction to allergens, <a href="https://link.springer.com/article/10.1007/s40641-015-0018-2">most notably pollen</a>. Typically associated with spring and early summer, hay fever symptoms appear to have intensified in the UK in recent weeks. </p>
<p>The <a href="https://www.itv.com/news/2023-06-13/why-is-hay-fever-so-bad-this-year">question</a> on many people’s minds is: why is it so bad right now? A number of environmental factors may be contributing to the current hay fever havoc – including <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/cea.12709?casa_token=U5iXSibofjUAAAAA:7FUUOQNyS0JFnkiDa7SEK6c8-lvL_fMHcDsqSUby2b3E5QA0F-ECRyZ0EuMXc3NlbXY9a_I_-dZk02Wx">thunderstorms</a>, which can exacerbate symptoms for people with allergies as well as asthma.</p>
<p>Changes <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/all.13210">in weather patterns</a>, such as increasing temperatures and more intense rainfall, and extended flowering seasons as a result of these trends, can have a significant influence on pollen production.</p>
<p>In particular, higher <a href="https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.820">temperatures</a> and elevated atmospheric carbon dioxide levels, which are primarily occurring <a href="https://theconversation.com/yes-more-carbon-dioxide-in-the-atmosphere-helps-plants-grow-but-its-no-excuse-to-downplay-climate-change-130603">as a result of climate change</a>, have been shown to stimulate plant growth and <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0111712">enhance pollen production</a>.</p>
<p>It’s likely these factors are contributing to <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2222.2004.02061.x">longer pollen seasons</a> and higher concentrations of allergenic pollen in the air, explaining why people are reporting hay fever symptoms at such high levels.</p>
<h2>What about thunderstorms?</h2>
<p>Hot weather often paves the way <a href="https://science.howstuffworks.com/nature/climate-weather/storms/question646.htm">for thunderstorms</a>, and some parts of the UK have had severe storms <a href="https://www.bbc.co.uk/news/uk-65879069">in recent days</a>. </p>
<p>The interaction between thunderstorms and respiratory conditions can lead to <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/cea.12709?casa_token=U5iXSibofjUAAAAA:7FUUOQNyS0JFnkiDa7SEK6c8-lvL_fMHcDsqSUby2b3E5QA0F-ECRyZ0EuMXc3NlbXY9a_I_-dZk02Wx">heightened symptoms</a> – not only for people with hay fever, but for those with asthma as well. </p>
<p>The phenomenon of <a href="https://ukhsa.blog.gov.uk/2022/03/18/thunderstorm-asthma-and-public-health-looking-back-to-move-forward/">thunderstorm asthma</a> has been observed in various parts of the world, and is characterised by a sudden surge in asthma attacks and respiratory distress following a thunderstorm. </p>
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Read more:
<a href="https://theconversation.com/got-allergies-you-could-be-at-lower-risk-of-catching-covid-188486">Got allergies? You could be at lower risk of catching COVID</a>
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<p>We don’t yet fully understand the precise mechanisms underlying thunderstorm asthma, but it’s likely the contributing factors are similar to those which explain why thunderstorms can worsen allergy symptoms.</p>
<p>During thunderstorms, a process called <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1398-9995.2006.01271.x">pollen fragmentation</a> occurs, where rainwater breaks down pollen granules into smaller particles. These fragmented pollen particles are then <a href="https://www.jacionline.org/article/S0091-6749(17)30425-6/fulltext">dispersed into the air</a>, which can increase pollen concentrations. </p>
<p>Notably, due to their smaller size, these particles can <a href="https://www.tandfonline.com/doi/abs/10.1080/09603123.2011.574269?casa_token=PyIcL5Ruf9sAAAAA:Z_mueNBNagZsq2UV16QZkH3s2id80axwyPhHfq2SqiOkU1MYIlo71OcmK_49k8b6sav_uB0NP58v8g">penetrate deeper into our airways</a>. As a result, people with hay fever and asthma may face <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.2007.01393.x">more severe symptoms</a> after a thunderstorm when we’re exposed to these fragmented pollen particles, compared to intact pollen grains alone.</p>
<p>The process of pollen fragmentation during thunderstorms can also <a href="https://www.jacionline.org/article/S0091-6749(17)30425-6/abstract">release allergenic proteins</a>, making the pollen particles more potent. This can trigger more severe allergic responses in both asthma and hay fever sufferers.</p>
<p>Meanwhile, thunderstorms can also release irritant particles and pollutants, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3410145/">such as dust and ozone</a>, which can irritate the airways and exacerbate respiratory symptoms in people with asthma and hay fever.</p>
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<img alt="An umbrella in the rain." src="https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/531977/original/file-20230614-29-zff5s3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Thunderstorms can exacerbate hay fever and asthma.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/rain-drops-falling-black-umbrella-concept-323261750">Brian A. Jackson/Shutterstock</a></span>
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<p>These factors highlight <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1398-9995.2006.01271.x">the complex interplay</a> between environmental triggers, pollen characteristics and respiratory health in relation to hay fever and asthma. Understanding these mechanisms can hopefully help us in developing effective strategies for managing and mitigating the effects of these conditions.</p>
<h2>How can I manage my hay fever symptoms?</h2>
<p>Pollen levels look set <a href="https://www.metoffice.gov.uk/weather/warnings-and-advice/seasonal-advice/pollen-forecast#?date=2023-06-14">to remain high</a> across much of the UK in the coming days, and possibly for some time after that if the current weather conditions continue. If you’re struggling with hay fever symptoms, here are a few tips. </p>
<p><strong>Check the pollen count in your area:</strong> This information can be found through <a href="https://www.metoffice.gov.uk/weather/warnings-and-advice/seasonal-advice/pollen-forecast#?date=2023-06-13">the Met Office</a>, local weather forecasts, online pollen trackers, or smartphone apps. Adjust your activities and precautions accordingly. For example, on days when the pollen count is high, it’s a good idea to <a href="https://www.sciencedirect.com/science/article/abs/pii/S1081120610635016">stay indoors</a> where possible, with windows and doors closed, to minimise pollen exposure.</p>
<p><strong>Practice good hygiene:</strong> After spending time outdoors, <a href="https://www.nhs.uk/conditions/hay-fever/">take a shower and change your clothes</a> to remove any pollen that may have accumulated on your body or clothing. This reduces the likelihood of bringing pollen into your living spaces.</p>
<p><strong>Use filters:</strong> If you drive, consider investing in a pollen filter for your car’s ventilation system to reduce the amount of pollen that enters the vehicle while travelling. Additionally, using a <a href="https://www.sciencedirect.com/science/article/abs/pii/009167499090050E">high-efficiency particulate air (Hepa) filter</a> at home can help remove pollen and other allergens from indoor air.</p>
<p><strong>Avoid triggers:</strong> Refrain from mowing the lawn or spending prolonged periods in freshly cut grass, as this can stir up pollen particles. Similarly, keeping <a href="https://www.webmd.com/allergies/best-worst-plants">fresh flowers inside the house</a> can introduce additional allergens into the environment, so it’s best to avoid having these indoors during hay fever season.</p>
<p><strong>Create a barrier:</strong> Try applying <a href="https://www.nhs.uk/conditions/hay-fever/">petroleum jelly</a> around the nostrils. This creates a barrier that can trap pollen and reduce its entry into the nasal passages, thereby providing some relief.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/future-hay-fever-seasons-will-be-worse-thanks-to-climate-change-34074">Future hay fever seasons will be worse thanks to climate change</a>
</strong>
</em>
</p>
<hr>
<p>While these tips can help alleviate symptoms, it’s important to consult with a healthcare professional for personalised advice and treatment options. They can provide guidance on suitable medications, <a href="https://theconversation.com/hay-fever-how-immunotherapy-can-help-sufferers-not-getting-relief-from-the-usual-treatments-204945">immunotherapy</a>, or other interventions to help manage your hay fever or asthma effectively.</p><img src="https://counter.theconversation.com/content/207666/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A number of environmental factors, including thunderstorms, are likely to be contributing to the current hay fever havoc.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1902352022-10-05T23:41:02Z2022-10-05T23:41:02ZPollen does more than make you sneeze. It can cause thunderstorm asthma, even if you’re not asthmatic<figure><img src="https://images.theconversation.com/files/488192/original/file-20221004-23-z8yzc0.jpg?ixlib=rb-1.1.0&rect=204%2C548%2C5259%2C3088&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/woman-has-reflux-acids-park-551855089">Shutterstock</a></span></figcaption></figure><p>Climate change has caused melting icebergs, flooding, and landslides. It can also bring about an <a href="https://pubmed.ncbi.nlm.nih.gov/33228867/">increase</a> in pollen levels, prolong the duration of pollen season, and <a href="https://ehp.niehs.nih.gov/doi/10.1289/EHP173">cause more</a> pollen-related health problems.</p>
<p>Pollen grains landing on the moist membranes of the nose or eyes cause “hay fever” (allergic rhinitis) in <a href="https://www.aihw.gov.au/reports/chronic-respiratory-conditions/allergic-rhinitis-hay-fever/contents/allergic-rhinitis">one in five people</a>. This often leads to a runny or blocked nose and itchy eyes.</p>
<p>During the pollen season, people with asthma are at greater risk of a flare-up. </p>
<p>Pollen can also trigger <a href="https://pubmed.ncbi.nlm.nih.gov/31759647/">thunderstorm asthma</a>, even in those <a href="https://pubmed.ncbi.nlm.nih.gov/33996193/">who haven’t been diagnosed</a> with asthma and hay fever. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/lush-grasslands-higher-allergy-risks-what-hay-fever-sufferers-can-expect-from-another-la-nina-season-189982">Lush grasslands, higher allergy risks – what hay fever sufferers can expect from another La Niña season</a>
</strong>
</em>
</p>
<hr>
<h2>What is thunderstorm asthma?</h2>
<p>Thunderstorms <a href="https://pubmed.ncbi.nlm.nih.gov/29880157/">cause</a> a drop in temperature and a sudden rise in humidity. This <a href="https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(18)30120-7/fulltext">can cause</a> whole grass pollen grains to rupture into particles that are tiny enough to penetrate deeper into the lungs, which causes thunderstorm asthma. </p>
<p>Because of this, a lot of people – even those with no known asthma – can be affected. </p>
<p>The largest thunderstorm asthma event occurred in Melbourne during the 2016 grass pollen season – some <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/resp.13410">10,000 people</a> were affected and hospital emergency departments were over-capacity by <a href="https://pubmed.ncbi.nlm.nih.gov/29880157/">at least 3,000</a> respiratory-related cases. Sadly, ten people also died from asthma that night. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/TMQxBZ9M8g8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This short Better Health Channel video gives a quick overview of thunderstorm asthma.</span></figcaption>
</figure>
<h2>Who is at risk of thunderstorm asthma?</h2>
<p>Even people who do not have a history of asthma are at risk of thunderstorm asthma. However, research has shown some people can be more susceptible to pollen than others. This includes:</p>
<ul>
<li>those with <a href="https://pubmed.ncbi.nlm.nih.gov/29229087/">pollen allergy</a>, specifically <a href="https://pubmed.ncbi.nlm.nih.gov/34774618/">ryegrass pollen allergy</a></li>
<li>people who have respiratory conditions such as <a href="https://www.jacionline.org/article/S0091-6749(21)01689-4/fulltext">asthma</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/29229087/">hay fever</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/26048665/">a cold</a>, and <a href="https://www.safercare.vic.gov.au/clinical-guidance/covid-19/epidemic-thunderstorm-asthma">COVID</a></li>
<li>being outdoors at <a href="https://pubmed.ncbi.nlm.nih.gov/29229087/">the time of the thunderstorm</a></li>
<li>people who are <a href="https://pubmed.ncbi.nlm.nih.gov/29573176/">of Asian ethnicity</a></li>
<li>people living in areas with <a href="https://pubmed.ncbi.nlm.nih.gov/33131877/">lots of plant life</a></li>
<li>children with <a href="https://pubmed.ncbi.nlm.nih.gov/35398553/">a food allergy or eczema</a></li>
<li>those with exposure to high levels of <a href="https://pubmed.ncbi.nlm.nih.gov/34116012/">air pollution</a></li>
<li>those with lower <a href="https://pubmed.ncbi.nlm.nih.gov/15723767/">socioeconomic status</a>, as reduced access to health care and poor quality housing can exacerbate symptoms. </li>
</ul>
<p>In our research, we found people with <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/all.14566">co-existing allergic conditions</a> (such as asthma and hay fever) to be more impacted by pollen compared to those with single allergic conditions (such as asthma only). </p>
<h2>How else can pollen cause harm?</h2>
<p>Even outside of thunderstorms, pollen alone can <a href="https://www.mdpi.com/1660-4601/19/12/7541">cause</a> asthma attacks requiring hospitalisations, respiratory symptoms such as wheezing and runny nose, and reduced lung function, making it harder to breath.</p>
<p>Despite a low mortality rate, allergic asthma and hay fever can cause further <a href="https://pubmed.ncbi.nlm.nih.gov/15698810/">burdens</a> such as additional <a href="https://erj.ersjournals.com/content/21/1/116">health-care costs</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/11029350/">poorer physical and mental health</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1577143799859535874"}"></div></p>
<p>Our yet-to-be-published research has shown grass pollen may trigger a general state of heightened immune responses, leading to increased risk of eczema flares in children. </p>
<p>Other <a href="https://www.sciencedirect.com/science/article/pii/S0022202X15321904">studies</a> have indicated children with eczema experience more symptoms such as a higher intensity of itchiness and rash on days with high levels of grass pollen.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sneezing-with-hay-fever-native-plants-arent-usually-the-culprit-190336">Sneezing with hay fever? Native plants aren't usually the culprit</a>
</strong>
</em>
</p>
<hr>
<h2>How can you prepare?</h2>
<p>So, what can you do to prepare for the grass pollen season and the threat of thunderstorm asthma?</p>
<ul>
<li>download your state’s emergency services app, such as the Victorian Emergency App, which can provide thunderstorm asthma alerts</li>
<li>keep an eye on pollen counts (see below for useful websites)</li>
<li>keep doors and windows closed on high pollen days</li>
<li>use air purifiers<br></li>
<li>stay indoors during high pollen counts or thunderstorm asthma alerts</li>
<li>plant non-allergenic flowers if you have a garden</li>
<li>keep wearing a face mask. <a href="https://pubmed.ncbi.nlm.nih.gov/34277327/">Masks</a> have shown to be very effective in reducing the risk of COVID-19 infection and pollen-induced respiratory symptoms</li>
<li>take anti-asthma medications. Reliever medications are available over-the-counter. Preventer medications offer much stronger protection but require a prescription from a doctor. They also need to be used preventatively in the setting of pollen-induced asthma, or in severe hay fever, to prevent thunderstorm asthma </li>
<li>take antihistamines such as Zyrtec, which can be used both on an as-needed basis or more regularly through the pollen season. However, it does not treat or prevent asthma. </li>
</ul>
<figure class="align-center ">
<img alt="Person uses an asthma inhaler" src="https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488189/original/file-20221004-12421-cqj3xb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">People with diagnosed asthma should take their preventer medication regularly during the pollen season.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/health-medicine-young-girl-using-blue-1503422258">Shutterstock</a></span>
</figcaption>
</figure>
<p>If you know you suffer from asthma, hay fever or pollen allergy, you are at risk of thunderstorm asthma. Aside from taking advantage of warning systems and staying out of the storm, you should see your doctor and have an asthma puffer at hand through the pollen season to keep yourself safe. Your doctor can advise you on the correct treatment. </p>
<p>Research including our own has shown pollen exposure can have a <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/all.14566">lagged effect</a> on the lungs and airways. This means asthma attacks or respiratory symptoms can sometimes occur a few days after exposure. So, if you forget to take medications pre-emptively, it’s not too late. However, go to a hospital if it gets severe. </p>
<p>Refer to the following websites for useful daily pollen information in Australia: <a href="https://airrater.org/">AirRater</a> or <a href="https://www.pollenforecast.com.au/">AusPollen</a>.</p><img src="https://counter.theconversation.com/content/190235/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shyamali Dharmage receives funding from the Australian National Health and Medical Research Council (NHMRC). She currently holds investigator-initiated grants from GSK and AstraZeneca for unrelated work. </span></em></p><p class="fine-print"><em><span>Jo Douglass has received honoraria for educational presentations from Astra-Zeneca, GSK, Novartis, Shire, & CSL. She has served on advisory boards: Sanofi-Aventis, Novartis, GSK, Astra-Zeneca, Shire, Immunosis, Equilium and CSL. She has undertaken contracted or investigator-initiated research for unrelated work on behalf of: GSK, Novartis, Immunosis, AstraZeneca, Sanofi-Aventis, Grifols, CSL, BioCryst & Equilium. She has a personal superannuation shareholding in CSL.</span></em></p><p class="fine-print"><em><span>Sabrina Idrose receives funding from the NHMRC Centre for Food and Allergy Research and LifeCourse PhD scholarships.</span></em></p>Pollen can trigger thunderstorm asthma, even in those without diagnosed asthma.Shyamali Dharmage, NHMRC Professorial Fellow, The University of MelbourneJo Douglass, Professor of Medicine, The University of MelbourneSabrina Idrose, PhD Candidate, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1899822022-09-14T00:33:26Z2022-09-14T00:33:26ZLush grasslands, higher allergy risks – what hay fever sufferers can expect from another La Niña season<figure><img src="https://images.theconversation.com/files/484227/original/file-20220913-22-djkxnd.jpg?ixlib=rb-1.1.0&rect=26%2C26%2C4427%2C2544&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://images.pexels.com/photos/129539/pexels-photo-129539.jpeg?auto=compress&cs=tinysrgb&w=1260&h=750&dpr=2">Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Australia has among the highest prevalence of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3353191/">asthma</a> and <a href="https://www.phrp.com.au/issues/december-2018-volume-28-issue-4/climate-change-and-allergy-in-australia-an-innovative-high-income-country-at-potential-risk/">hay fever</a> globally. La Niña (and El Niño) will undoubtedly affect allergy sufferers. </p>
<p>Sea-surface temperatures across the east-central equatorial Pacific <a href="https://www.nature.com/articles/s43017-021-00199-z">cycle between episodes</a> of La Niña (when the sea is cooler) and El Niño (when it is warmer). These complex weather patterns are likely to alter the amount of pollen in the air. </p>
<p>A La Niña event has been <a href="https://www.abc.net.au/news/2022-09-13/bom-declares-third-la-nina-summer-weather-flood-risk/101424100">declared</a> for the third year in a row, increasing the likelihood eastern and northern Australia will be wetter than normal. This will raise health concerns for some people due to prolific pastureland growth and more grass pollen. </p>
<p>Allergic rhinitis (hay fever) and asthma can be <a href="https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/pollen-allergy">triggered</a> by pollen from grasses, weeds or trees. Thunderstorms can also be a trigger.</p>
<p>Record rainfalls in regional Victoria led up to Australia’s most catastrophic respiratory allergy event in November 2016, when <a href="https://www.thelancet.com/pdfs/journals/lanplh/PIIS2542-5196(18)30120-7.pdf">thunderstorm asthma</a> was linked to several thousand trips to Melbourne hospital emergency departments and ten deaths. </p>
<p>But our understanding of how climate change is affecting risk is limited by sparse and intermittent <a href="https://doi.org/10.1016/j.envres.2022.113762">pollen monitoring in Australia</a>. We’ll need continuous pollen records for at least ten or 20 years to track the effects on pollen exposure.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-climate-scientist-on-the-planets-simultaneous-disasters-from-pakistans-horror-floods-to-europes-record-drought-189626">A climate scientist on the planet's simultaneous disasters, from Pakistan’s horror floods to Europe’s record drought</a>
</strong>
</em>
</p>
<hr>
<h2>Climate change and what to expect</h2>
<p>Climate change appears to increase our exposure to airborne allergens such as grass pollen. <a href="https://doi.org/10.3389/falgy.2021.705313">Research</a> recently showed the amount of Brisbane grass pollen measured from 2016 to 2020 was almost triple the amount monitored between 1994 and 1999. </p>
<p>This was linked with increasing carbon dioxide in the atmosphere, increasing temperature and lusher vegetation. The number and proportion of days with grass pollen at high and extreme levels increased significantly over time, bringing more health risks. </p>
<p>Highly elevated grass pollen levels were also seen during <a href="https://auspollen.edu.au/brisbane/">the 2021 grass pollen season</a> up until flooding in February 2022. </p>
<p>It’s early days, but given the <a href="http://www.bom.gov.au/climate/enso/">declaration of another La Niña season</a>, the upcoming grass pollen season will likely to be high again this spring and summer at least in some parts of Australia.</p>
<p>Pollen exposure differs significantly <a href="https://link.springer.com/article/10.1007/s10453-015-9399-x">between locations and years</a>. So understanding local environmental drivers is important. </p>
<p>Using over 20 years of <a href="https://www.nature.com/articles/s43017-022-00298-5">satellite data</a> and ground-based cameras to monitor the life cycle of grasses (including peak growth periods, flowering and pollination) we’ve shown climate change is <a href="https://doi.org/10.1016/j.rse.2022.112983">altering the composition of grasslands</a> with warm season grasses steadily increasing. Changes in the types of grasses growing alter allergen composition, severity, and the seasonal timing of pollen exposure. This is important for <a href="https://onlinelibrary.wiley.com/doi/10.1002/cti2.1103">sensitisation, diagnosis and management</a> of people with hay fever.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="pollen in the air" src="https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/484226/original/file-20220913-24-endbpe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Longer seasons for warm season grasses can exacerbate allergic conditions.</span>
<span class="attribution"><a class="source" href="https://image.shutterstock.com/image-photo/dust-pollen-small-particles-fly-600w-1386898265.jpg">Shutterstock</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/do-i-have-covid-or-hay-fever-heres-how-to-tell-188030">Do I have COVID or hay fever? Here’s how to tell</a>
</strong>
</em>
</p>
<hr>
<h2>Keeping track of pollen</h2>
<p>Currently, pollen monitoring is mostly undertaken by academic research groups dependent on short-term competitive funding. </p>
<p>Australia is several years behind Europe and Japan in adopting <a href="https://doi.org/10.1002/clt2.12015">automated, real-time pollen monitoring</a>. Our current manual pollen monitoring processes are labour intensive and <a href="https://link.springer.com/article/10.1007/s10453-020-09656-6">imprecise</a>. </p>
<p>For Australia to set up similar monitoring, instruments would need to learn to detect, match and count local pollens and be capable of operating over time in our diverse and often harsh external environments. </p>
<p>Access to real-time automated pollen monitoring across a broad coverage of sites would help with pollen forecasting. This could inform both short-term daily pollen forecasts, and early pollen season warnings. </p>
<p>While there are approximately <a href="https://auspollen.edu.au/auspollensitesmap/">25 active pollen monitoring sites in Australia</a>, these are mostly located in urban areas, and across Victoria. We need a wider network of monitoring sites to serve community needs and to foster better understanding of <a href="https://gmd.copernicus.org/articles/12/2195/2019/">pollen sources</a> and health implications.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1569482147794415616"}"></div></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/no-not-again-a-third-straight-la-nina-is-likely-heres-how-you-and-your-family-can-prepare-188970">No, not again! A third straight La Niña is likely – here’s how you and your family can prepare</a>
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</p>
<hr>
<h2>A national approach to allergies</h2>
<p>The freshly launched <a href="https://www.allergy.org.au/about-ascia/info-updates/launch-of-national-allergy-council-and-national-allergy-centre-of-excellence">National Allergy Centre for Excellence</a> will hopefully push for all Australians with pollen allergies to have access to accurate pollen information. </p>
<p>For now, those with allergies should keep an eye on the <a href="https://asthma.org.au/pollen-monitoring/">currently available</a> pollen counts. If you need <a href="https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/pollen-allergy">advice on how to better manage your pollen allergies</a>, especially if you are at risk of <a href="https://www.sciencedirect.com/science/article/pii/S0091674921016894?via%3Dihub">seasonal allergic asthma</a>, consult your pharmacist or discuss treatment options with your doctor. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1569504210684903424"}"></div></p><img src="https://counter.theconversation.com/content/189982/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janet Davies has received funding in the last five years from National Health and Medical Research Council (GNT1116107), Australian Research Council (DP210100347, LP190100216, DP190100376, DP170101630), National Foundation of Medical Research Innovation with co-funding from Abionic Switzerland. QUT owns patents granted for allergy diagnostics.</span></em></p><p class="fine-print"><em><span>Alfredo Huete receives funding from the Australian Research Council (DP210100347, DP170101630), the Terrestrial Ecosystem Research Network (TERN), the National Health and Medical Research Council (GNT1116107), and Climate-KIC Australia Fairwater Living Lab.</span></em></p><p class="fine-print"><em><span>Paul Beggs does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A third La Niña event in a row could bring dangerous conditions for people with allergies – but we’ll need better continuous monitoring to be sure what’s coming in the future.Janet Davies, Professor, Queensland University of TechnologyAlfredo Huete, Professor, Climate Change Cluster, University of Technology SydneyPaul Beggs, Associate Professor and Environmental Health Scientist, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/863972017-11-06T02:54:49Z2017-11-06T02:54:49ZThunderstorm asthma: who’s at risk and how to manage it<figure><img src="https://images.theconversation.com/files/192554/original/file-20171031-18700-hgpomh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Hay fever sufferers should have access to an asthma puffer every spring, even if they've never had asthma symptoms.</span> <span class="attribution"><span class="source">from www.shutterstock.com</span></span></figcaption></figure><p>Late in the afternoon of a hot spring day, November 21, 2016, a thunderstorm from the northwest swept over Geelong and Melbourne, triggering the <a href="http://www.theage.com.au/victoria/recordbreaking-thunderstorm-asthma-epidemic-could-change-medical-advice-20161129-gt08iy.html">world’s most devastating thunderstorm asthma epidemic</a>.</p>
<p>The scale and impact of this unparalleled public health emergency took Victorians by surprise. Thousands of people began, almost simultaneously, to experience breathing difficulties, because stormy winds and moisture can break up pollen into particles small enough to enter the airways.</p>
<p>Through valiant efforts by the ambulance service, hospital networks, general practitioners and pharmacists, the vast majority of thunderstorm-affected patients were successfully treated. Tragically, ten people died, and their deaths are <a href="http://www.theage.com.au/victoria/coronial-investigation-uncovers-tenth-thunderstorm-asthma-death-20171018-gz3j59.html">now under coronial investigation</a>. </p>
<p>Of the ten <a href="https://www2.health.vic.gov.au/about/publications/researchandreports/thunderstorm-asthma-literature-review-may-2107">thunderstorm asthma epidemics reported in Australia</a>, seven were in Melbourne. This highlights the city’s vulnerability to unique interactions between particular types of thunderstorms and springtime grass pollen exposure. But other temperate regions around Australia where grasses are cultivated for animal feed have also experienced thunderstorm asthma, such as Wagga Wagga in New South Wales. Thunderstorm asthma events may be influenced and potentially worsened by emerging changes in climate.</p>
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Read more:
<a href="https://theconversation.com/explainer-what-is-thunderstorm-asthma-4159">Explainer: what is thunderstorm asthma?</a>
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<p>During the past year, government, universities, peak professional bodies and non-government organisations have worked collectively to <a href="https://www2.health.vic.gov.au/public-health/environmental-health/climate-weather-and-public-health/thunderstorm-asthma/response">review the event</a>, understand the factors behind thunderstorm asthma, and <a href="https://www2.health.vic.gov.au/public-health/environmental-health/climate-weather-and-public-health/thunderstorm-asthma/program">implement plans</a> to prevent a repeat of this tragedy.</p>
<h2>Who’s at risk and what should they be doing?</h2>
<p>Advice to patients and health care professionals on understanding and managing the risk of thunderstorm asthma <a href="https://www.nationalasthma.org.au/living-with-asthma/resources/health-professionals/information-paper/thunderstorm-asthma">is now available</a>. The documents focus on the biggest risk factors: those who have hay fever and asthma.</p>
<p><strong>Hay fever</strong></p>
<p>In Australia, the biggest risk factor for thunderstorm asthma has been termed the “<a href="http://www.sciencedirect.com/science/article/pii/S0954611117303517">ryegrass pollen trifecta</a>”. That is, sensitisation to ryegrass pollen, springtime hay fever, and exposure to high levels of ryegrass pollen on the arrival of the thunderstorm. Ryegrass is one of the most common grasses in southern regions of Australia. In Victoria, ryegrass pollen levels are highest between mid-October and late December. </p>
<p>While it’s tempting for people to trivialise hay fever, the <a href="http://medicinetoday.com.au/2015/october/feature-article/hay-fever-%E2%80%93-underappreciated-and-chronic-disease">condition can be serious, debilitating and chronic</a>. Most people with hay fever manage their condition by taking antihistamines. They should also speak to their pharmacist or GP about <a href="https://theconversation.com/hay-fever-survival-guide-why-you-have-it-and-how-to-treat-it-34000">using daily steroid preventer nasal sprays</a>, which modify the disease process. </p>
<p>Patients with severe hay fever symptoms can be referred to an allergy specialist. In those whose condition can’t be managed by other medications, allergy specialists may recommend <a href="https://www.allergy.org.au/patients/allergy-treatment/immunotherapy?highlight=WyJpbW11bm90aGVyYXB5Il0=">allergen-specific immunotherapy</a>. This controls and treats the underlying allergic inflammation.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/keeping-one-step-ahead-of-pollen-triggers-for-thunderstorm-asthma-69408">Keeping one step ahead of pollen triggers for thunderstorm asthma</a>
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<p>For thunderstorm asthma protection, the <a href="https://www.nationalasthma.org.au/living-with-asthma/resources/health-professionals/information-paper/thunderstorm-asthma">National Asthma Council of Australia recommends</a> that people with hay fever in locations at risk of thunderstorm asthma carry an asthma puffer, available at any pharmacy without prescription, or know where they can easily get one.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/192558/original/file-20171031-18738-14zvmt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192558/original/file-20171031-18738-14zvmt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/192558/original/file-20171031-18738-14zvmt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192558/original/file-20171031-18738-14zvmt6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192558/original/file-20171031-18738-14zvmt6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192558/original/file-20171031-18738-14zvmt6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192558/original/file-20171031-18738-14zvmt6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192558/original/file-20171031-18738-14zvmt6.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">Many of those affected were outside before or during the thunderstorm.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
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<p><strong>Asthma</strong></p>
<p>At even higher risk of thunderstorm asthma are people with hay fever and known asthma. It’s important for them to seek medical review, update their asthma action plans and, if prescribed regular preventative medication, to take it regularly.</p>
<p>Of greatest concern are those with hay fever but who also experience symptoms of breathlessness, cough, chest tightness or wheezing during spring with their hay fever. They may have undiagnosed asthma and are particularly vulnerable to thunderstorm asthma, as they have not been prescribed asthma preventers or trained to manage their asthma. Media campaigns are now underway to alert such individuals of their need for medical consultation.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/pollen-counting-is-not-something-to-be-sneezed-at-18100">Pollen counting is not something to be sneezed at</a>
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<h2>Are there tests to tell if you’re at risk?</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/193331/original/file-20171106-1017-q81trg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/193331/original/file-20171106-1017-q81trg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/193331/original/file-20171106-1017-q81trg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/193331/original/file-20171106-1017-q81trg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/193331/original/file-20171106-1017-q81trg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/193331/original/file-20171106-1017-q81trg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/193331/original/file-20171106-1017-q81trg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/193331/original/file-20171106-1017-q81trg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">People with asthma should protect themselves with regular preventer use.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
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<p>GPs can arrange blood tests to confirm whether a person is sensitised to an allergen. This blood test measures levels of a specific antibody to an allergen source, such as ryegrass pollen. Subtropical grass pollens (such as Bahia and Bermuda) are also abundant and relevant in parts of Australia. </p>
<p>Patients referred to an allergy specialist may undergo <a href="https://www.allergy.org.au/images/pcc/ASCIA_PCC_Allergy_testing_2017.pdf">skin prick testing</a> to identify the allergens to which they are sensitised. Droplets of allergen extracts are placed on the skin and a small skin prick allows the allergen to penetrate the outer layer of skin. In patients sensitised to the allergen, a small red, swollen mark forms around the site within a few minutes.</p>
<p>A person who is not sensitised to ryegrass pollen (by either blood or skin prick testing) is very unlikely to experience thunderstorm asthma in Australia. </p>
<h2>Should those at risk be watching the weather?</h2>
<p><a href="http://www.sciencedirect.com/science/article/pii/S0954611117303517">Most patients</a> affected by thunderstorm asthma last year were outside, or inside with open windows, at the onset of the storm. Therefore, people who may be vulnerable to pollen allergies and thunderstorm asthma should be aware that exposure to weather and environmental conditions can lead to exacerbation of symptoms. During high-risk periods, they should stay indoors with all windows shut.</p>
<p>Based on a newly established network to monitor grass pollen exposure across Victoria regional forecasts of <a href="https://www2.health.vic.gov.au/public-health/environmental-health/climate-weather-and-public-health/thunderstorm-asthma/forecasting">thunderstorm asthma risk</a> now provide alerts to individuals and emergency services.</p>
<p>Pollen forecasts are available from the <a href="http://www.pollenforecast.com.au/">AusPollen Partnership sites</a>, in Melbourne, Brisbane, Sydney and Canberra. <a href="https://airrater.org/">AirRater</a> provides pollen information in Tasmania.</p><img src="https://counter.theconversation.com/content/86397/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janet Davies receives funding from National Health and Medical Research Council, Australian Research Council, Queensland University of Technology and the Bureau of Meteorology. Her University has received contracted research funds from Stallergenes Pty Ltd, Honorarium from Glaxo Smith Kline, Wymedical, and Meda and in kind research support from ThermoFisher (Sweden) and Sullivan Nicolaides Pathology (Australia). She is a named inventor of patents owned by QUT for uses of subtropical grass pollen allergens.</span></em></p><p class="fine-print"><em><span>Francis Thien and Mark Hew 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>What you should be doing this thunderstorm asthma season.Janet Davies, Associate professor, Queensland University of TechnologyFrancis Thien, Adjunct professor, Monash UniversityMark Hew, Head of Allergy, Asthma & Clinical Immunology, Alfred Health, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/694082016-12-07T03:10:04Z2016-12-07T03:10:04ZKeeping one step ahead of pollen triggers for thunderstorm asthma<figure><img src="https://images.theconversation.com/files/148794/original/image-20161206-25760-1k0h6g9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">After the storm ... Researchers are working together to predict future outbreaks of thunderstorm asthma.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/523779817?src=hsw7-e2BWnxmjB5R_CJwAw-1-2&id=523779817&size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>The recent <a href="http://www.abc.net.au/news/2016-11-29/thunderstorm-asthma-eighth-person-dies-from-melbourne/8074776">Melbourne thunderstorm asthma event</a> has led some people to question what made this hay fever season so bad and how this tragic event occurred.</p>
<p>Thunderstorm asthma, a sudden surge in cases of acute respiratory illness coinciding with local thunderstorms, ranges from small events that affect handfuls of people to large-scale epidemics that impact a whole city and severely strain the capacity of emergency services.</p>
<p>Thunderstorm asthma occurs when a complex interaction of meteorological and biological factors affects a group of susceptible individuals.</p>
<p>We don’t yet know the clinical circumstances and allergic sensitivities of those who sought medical care on the night of the recent episode. But, based on similar events in Australia, most will likely have been allergic to grass pollen, in particular <a href="http://erj.ersjournals.com/content/16/1/3.short">rye grass pollen</a>. </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/1603007">Studies of previous Melbourne thunderstorm asthma events</a> favoured grass pollen as the cause, rather than other possible triggers such as dust particles. Elsewhere, fungal spores have been <a href="http://www.sciencedirect.com/science/article/pii/S0091674907009700">implicated</a>.</p>
<p>Another aspect of these events is that <a href="https://www.mja.com.au/journal/2011/195/9/thunderstorm-asthma-timely-reminder">generally around a third of the affected people</a> have no previous experience of asthma. This elevates anxiety in the community and complicates management and patient advice.</p>
<h2>What’s the outlook?</h2>
<p>While severe thunderstorm asthma epidemics are uncommon, there is no guarantee they will remain so. There is more grass pollen in years with <a href="http://link.springer.com/article/10.1007%2Fs00484-010-0361-x">high winter and spring rainfall</a> and this past spring <a href="http://www.bom.gov.au/climate/mwr/aus/mwr-aus-201609.pdf">rainfall was exceptionally high across much of Australia</a>. Victoria was no exception. </p>
<p>While it has been the worst grass pollen season we’ve seen for a few years, it <a href="http://www.melbournepollen.com.au/index.php/mobile-news/85-forecasting-the-grass-pollen-season">could have been a lot worse</a>.</p>
<p>The main source of Melbourne’s grass pollen is pastures to the city’s north and west. <a href="https://theconversation.com/hay-fever-misery-prediction-some-to-get-off-lightly-others-to-suffer-32378">Warm north and north-westerly winds carry this pollen into the city</a>. Keeping a lid on the current season has been Melbourne’s <a href="http://www.bom.gov.au/climate/current/month/vic/melbourne.shtml">cooler-than-average November</a> and southerly pollen-free winds from Bass Strait. </p>
<p>Paradoxically, thunderstorm asthma can occur in dry years as well as wet ones. Despite below-average rainfall in 2003, Melbourne still had an episode of <a href="https://www.ncbi.nlm.nih.gov/pubmed/22515396">thunderstorm asthma</a>.</p>
<p>One of the main drivers of higher rainfall in Australia is a weather pattern called <a href="http://www.bom.gov.au/climate/glossary/lanina.shtml">La Nina</a>. <a href="http://www.nature.com/nclimate/journal/v5/n2/full/nclimate2492.html">Recent modelling</a> points to an increased frequency of extreme La Nina events, from one roughly every 23 years in the 20th century, to one every 13 years this century. </p>
<p>Also of concern is the possibility of plants producing pollen that is more allergenic because the atmosphere contains <a href="http://www.publish.csiro.au/fp/FP05039">more CO₂</a> or days are <a href="http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2222.1998.00404.x/abstract">warmer</a>.</p>
<p>By contrast, there is a mixed <a href="https://www.climatechangeinaustralia.gov.au/media/ccia/2.1.6/cms_page_media/168/CCIA_2015_NRM_TR_Chapter%207.pdf">outlook</a> in coming decades for meteorological factors that may contribute to thunderstorm asthma. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/148772/original/image-20161206-25724-1opp1nb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/148772/original/image-20161206-25724-1opp1nb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/148772/original/image-20161206-25724-1opp1nb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/148772/original/image-20161206-25724-1opp1nb.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/148772/original/image-20161206-25724-1opp1nb.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/148772/original/image-20161206-25724-1opp1nb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/148772/original/image-20161206-25724-1opp1nb.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/148772/original/image-20161206-25724-1opp1nb.jpeg?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">Satellite images showing the thunderstorm that hit Melbourne on November 21 2016 and how it developed over the day. The green area represents very cold cloud-top temperatures of the thunderstorm complex over Melbourne.</span>
<span class="attribution"><span class="source">Regional and Mesoscale Meteorology Branch (RAMMB) of NOAA/NESDIS/Supplied</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Although rainfall totals across much of southern Australia are projected to decline (particularly during winter and spring), the <a href="https://theconversation.com/australia-faces-a-stormier-future-thanks-to-climate-change-35327">frequency of severe thunderstorms is likely to increase</a>. </p>
<p>Considering all these factors, it would be imprudent to dismiss the recent catastrophic episode of thunderstorm asthma as a “freak event” that is unlikely to reoccur.</p>
<h2>An integrated approach to pollen forecasting</h2>
<p>Forecasting the levels and types of pollen across Australia is one way for us to better understand, predict and mitigate thunderstorm asthma epidemics.</p>
<p><a href="http://www.pollenforecast.com.au">AusPollen</a>, a <a href="http://www.sciencedirect.com/science/article/pii/S0048969715004301">team</a> of researchers and stakeholders involved in providing care and education to those affected, will measure and provide information on grass pollen levels in <a href="http://www.melbournepollen.com.au">Melbourne</a>, <a href="http://www.canberrapollen.com.au">Canberra</a>, <a href="http://www.sydneypollen.com.au">Sydney</a> and <a href="http://www.brisbanepollen.com.au">Brisbane</a> over the next three years. The information will be provided directly to the public via apps tailored to their city.</p>
<p>This information will then be used to develop a system to forecast the load and distribution of grass pollen. Strong partnership between researchers, allergy and respiratory doctors, Asthma Australia and government departments is needed to help public health authorities put in place warning systems for those at risk.</p>
<h2>What can patients do now?</h2>
<p>People with <a href="https://theconversation.com/hay-fever-survival-guide-why-you-have-it-and-how-to-treat-it-34000">hay fever</a> are advised to take their condition seriously. They should start by seeking support from a pharmacist or GP to manage their condition with over-the-counter medications (anti-histamines and/or intranasal corticosteroids). </p>
<p>If symptoms remain troublesome or affect your breathing, then seek medical advice. Allergen immunotherapy can be effective in managing grass <a href="http://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/pollen-allergy">pollen allergy</a> and reducing the risk of asthma. </p>
<p>Those with known asthma are advised to use their medications as prescribed by their doctor. Particularly be careful to use an asthma preventer appropriately to <a href="https://www.asthmaaustralia.org.au/nsw/about-asthma/manage-your-asthma/triggers/asthma-and-thunderstorms">keep symptoms under control</a>. Ensure you have an asthma action plan and consult your doctor for regular assessment and ongoing management.</p><img src="https://counter.theconversation.com/content/69408/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ed Newbigin is a member of the AusPollen Partnership which receives funding from the NHMRC. </span></em></p><p class="fine-print"><em><span>Alfredo Huete receives funding from the National Health and Medical Research Council, The Australian Research Council, NSW-RAAP, TERN, and UTS. </span></em></p><p class="fine-print"><em><span>Janet Davies receives funding from the National Health and Medical Research Council, the Australian Research Council, The National Foundation for Medical Research Innovation and the Queensland University of Technology. The NHMRC AusPollen Partnership is co-sponsored with in kind and cash contributions from the Australasian Society for Clinical Immunology and Allergy, Asthma Australia, CSIRO, Bureau of Meteorology, MeteoSwiss (Switzerland), Stallergenes (Australia). Her work has been supported by untied funding from MSD, education support from Meda and GSK, collaborative research agreements from Stallergenes (France), and in kind sponsorship by Sullivan Nicolaides Pathology (QLD, Australia) and Thermofisher (Sweden). Davies has been invited to serve on the scientific advisory board of an allergen immunotherapy company.</span></em></p><p class="fine-print"><em><span>Jeremy Silver's position is funded by The University of Melbourne's McKenzie Postdoctoral Fellowship scheme. </span></em></p><p class="fine-print"><em><span>Assoc Prof Paul Beggs receives funding from Australia’s National Health and Medical Research Council (NHMRC) and the Australian Research Council (ARC). </span></em></p><p class="fine-print"><em><span>Beth Ebert 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>Researchers from a range of disciplines need to work together if we are to predict and prepare for the next thunderstorm asthma event.Ed Newbigin, Associate Professor of Botany, The University of MelbourneAlfredo Huete, Professor, Climate Change Cluster, University of Technology SydneyBeth Ebert, Research program leader for Weather and Environmental Prediction, Bureau of Meteorology R&D Branch, Australian Bureau of MeteorologyJanet Davies, Associate professor, Queensland University of TechnologyJeremy Silver, Postdoctoral research fellow, The University of MelbournePaul Beggs, Environmental Health Scientist, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/695642016-12-04T19:09:11Z2016-12-04T19:09:11ZCan we blame climate change for thunderstorm asthma?<figure><img src="https://images.theconversation.com/files/148229/original/image-20161201-17781-10p4m91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Climate change can cause higher pollen counts</span> <span class="attribution"><a class="source" href="https://unsplash.com/search/allergy?photo=Hez3-whPnNA">Lukasz Szmigiel/Unsplash</a></span></figcaption></figure><p>Australians have been left unsettled by the recent thunderstorm asthma event that <a href="http://www.theage.com.au/victoria/eight-now-dead-from-thunderstorm-asthma-20161129-gszt5z.html">claimed eight lives in Melbourne</a>. As with previous extreme weather events, we are left to wonder whether it was climate change at work, if it will happen again and if it will be worse next time. </p>
<p>We can’t say for sure if the thunderstorm asthma event was caused directly by climate change. But modelling each extreme event is neither feasible nor necessary. All weather events should now be considered in the context of climate change and general <a href="http://templatelab.com/IPCC-WG2AR5-SPM-FINAL/">climate projections</a> are sufficiently alarming to justify the need for governments to prepare for, and adapt to, new risks these pose to our health.</p>
<h2>How climate change affects Australia</h2>
<p><a href="https://www.climatechangeinaustralia.gov.au/media/ccia/2.1.6/cms_page_media/168/CCIA_2015_NRM_TR_Executive%20Summary.pdf">Updated projections</a> from the Bureau of Meteorology and the national science body, CSIRO, outline Australia has warmed 0.9°C since 1910 and can be expected to warm a further 0.6°C to 5.1°C by 2090, depending on reductions in greenhouse gases.</p>
<p>Hotter days will be more common and more severe. Rainfall during the cooler seasons will decrease in southern Australia while extreme rain events will become more common, particularly in the tropics. Ocean acidification and sea level rise will continue, wind speeds may decrease and tropical cyclones may become more intense but less frequent.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/148376/original/image-20161202-25653-18rfbfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/148376/original/image-20161202-25653-18rfbfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/148376/original/image-20161202-25653-18rfbfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/148376/original/image-20161202-25653-18rfbfk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/148376/original/image-20161202-25653-18rfbfk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/148376/original/image-20161202-25653-18rfbfk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/148376/original/image-20161202-25653-18rfbfk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/148376/original/image-20161202-25653-18rfbfk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Extreme rain events will become more common, especially in the tropics.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/search/rain-storm?photo=tT_SrSMhhgE">Glenn Carstens-Peters/Unsplash</a></span>
</figcaption>
</figure>
<p>Severe thunderstorms are <a href="http://www.cawcr.gov.au/projects/vicci/wp-content/uploads/2016/02/Dowdy.pdf">projected to be more common</a> in eastern Australia; about 14% more frequent in Brisbane and 30% in Sydney. Unlike heat and rainfall projections, links between climate change and thunderstorms in Australia are less well understood due to uncertainty around the physical processes that underpin them.</p>
<p>Thunderstorms can be dangerous due to accompanying winds, lightning and flash floods, as well as their potential to <a href="https://theconversation.com/explainer-what-is-thunderstorm-asthma-4159">rupture pollen into tiny particles</a> that can be inhaled into the lungs. In general, global warming can trigger asthma, and other illnesses, through increased baseline <a href="http://www.tandfonline.com/doi/full/10.1586/17476348.2013.814367">pollen and ground-level pollutants</a> such as ozone. </p>
<p>Climate change also poses a health risk beyond asthma and thunderstorms that is critical to prepare for.</p>
<h2>How our health will be affected</h2>
<p>Climate change <a href="http://www.bmj.com/cgi/doi/10.1136/bmj.e1359">poses a threat to health</a> directly through extreme weather events, warmer average temperatures and sea level rise. Indirectly it can destabilise the systems that keep our air clean, produce our food, provide us with fresh drinking water and enable economies to thrive. These shifts pose a threat to <a href="http://www.nature.com/scientificamerican/journal/v296/n6/full/scientificamerican0607-43.html">livelihoods</a>, <a href="http://www.bmj.com/cgi/doi/10.1136/bmj.e1356">food and water security</a>, and <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2815%2960854-6/fulltext">social and political stability</a>.</p>
<p>Heatwaves and reduced rainfall pose the greatest threat to Australians’ health and livelihoods. Indirectly, these changes will increase the severity of bushfires and droughts. These and other extreme events are a significant risk to physical and <a href="http://link.springer.com.ezp.lib.unimelb.edu.au/article/10.1007/s00038-009-0112-0">mental health</a>. </p>
<p>Extreme prolonged heat <a href="http://aph.sagepub.com.ezp.lib.unimelb.edu.au/content/23/2_suppl/27S.full.pdf+html">can trigger acute heat stroke</a> and dehydration or exacerbate underlying illnesses such as heart and kidney disease. Rates of <a href="http://www.who.int/globalchange/publications/climchange.pdf">injury, crime and domestic violence also increase</a> in heatwaves. Melbourne’s 2009 heatwave was associated with a <a href="http://aph.sagepub.com.ezp.lib.unimelb.edu.au/content/23/2_suppl/27S.full.pdf+htm;">62% increase in deaths and 46% increase in ambulance emergencies</a>. </p>
<p>The elderly, the young, those with chronic disease and those engaged in physical outdoor work are especially vulnerable.</p>
<p>Infectious diseases pose a different challenge. In warmer climates, the <a href="http://onlinelibrary.wiley.com.ezp.lib.unimelb.edu.au/doi/10.1890/08-0079.1/full">transmission potential</a> of mosquito-borne diseases such as malaria is increased. As warmer climates expand southwards, malaria, dengue and Ross River virus will occur in new regions of Australia.</p>
<p>Although thunderstorm asthma has been well documented and has <a href="http://theconversation.com/we-couldve-seen-thunderstorm-asthma-coming-and-there-are-ways-to-prepare-69216">previously occurred in Melbourne</a>, the recent storm revealed that public and health services were unprepared. </p>
<p>In explaining the difficulty of adequately responding to the crisis, Victoria’s health minister Jill Hennessy <a href="http://www.heraldsun.com.au/news/victoria/melbourne-thunderstorm-asthma-victim-dies-eight-days-after-70minute-ambulance-wait/news-story/5d72a024ab48fff8a90c12eab7d07318">likened it to 150 bombs going off</a> in different places at once. With current climate change projections, governments need better planning for the likelihood of similar crises.</p>
<h2>Getting prepared</h2>
<p>There are increasing demands from the health sector for a <a href="https://d3n8a8pro7vhmx.cloudfront.net/caha/pages/40/attachments/original/1476390215/CAHA_Discussion_Paper_v04.pdf?1476390215">national strategy to address climate change</a> and the related health concerns. Such action would also address Australia’s international obligations to develop and report on national climate change adaptation strategies, and to achieve strong greenhouse gas emissions reductions.</p>
<p>Key elements of <a href="http://www.ncbi.nlm.nih.gov.ezp.lib.unimelb.edu.au/pubmed/21108905">health sector adaptation </a> include early warning systems and more adequate preparation of the workforce. Health professionals need to <a href="http://www.jphres.org/index.php/jphres/article/view/673">learn about climate change</a> and related risks to be able to identify vulnerable people, such as the elderly and those with pre-existing conditions, participate in emergency responses and contribute to health system stewardship. </p>
<p>Similar adaptation strategies can often be implemented for different climate risks. For example, the risk from heatwaves and thunderstorms could both be reduced by <a href="http://link.springer.com.ezp.lib.unimelb.edu.au/article/10.1007/s00484-007-0132-5">early warning systems</a>, <a href="http://www.sciencedirect.com.ezp.lib.unimelb.edu.au/science/article/pii/S0277953609006625">vulnerability mapping</a> and public health education. </p>
<p>However, while predicting a thunderstorm may be relatively straightforward, <a href="http://qjmed.oxfordjournals.org.ezp.lib.unimelb.edu.au/content/qjmed/106/3/207.full.pdf">predicting acute asthma epidemics</a> requires a detailed understanding of the process and sensitive monitoring of allergens in the air.</p>
<p>Irrespective of whether climate change contributed to the thunderstorm in Melbourne last week, we can be sure that Australia’s climate projections herald new risks to health that cannot be ignored.</p><img src="https://counter.theconversation.com/content/69564/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janie Maxwell receives funding from the Department of Health for research in climate change and human health. Janie is a member of the Victorian committee of Doctors for the Environment Australia.</span></em></p>Irrespective of whether climate change contributed to the thunderstorm in Melbourne last week, we can be sure Australia’s climate projections herald new risks to health that cannot be ignored.Janie Maxwell, Associate Lecturer in Climate Change and Health, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/694262016-11-29T01:57:19Z2016-11-29T01:57:19ZIt’s not just about Melbourne: why we need a national approach to ‘thunderstorm asthma’<figure><img src="https://images.theconversation.com/files/147686/original/image-20161128-32004-1n1wvj2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Why didn't we learn the lessons from earlier thunderstorm asthma events? </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/519608404?src=Nv_s5WxZbVCfryXJs0M0zg-1-99&id=519608404&size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>The tragic deaths of <a href="http://www.abc.net.au/news/2016-11-27/sixth-person-dies-from-thunderstorm-asthma-emergency/8061380">at least six people</a>, apparently from <a href="https://theconversation.com/explainer-what-is-thunderstorm-asthma-4159">thunderstorm asthma</a>, highlights the risk from environmental hazards, even in seemingly safe urban centres in developed nations like Australia.</p>
<p>Events such as these, and others like the <a href="https://croakey.org/the-hazelwood-fire-health-risks-and-public-health-response-options/">Hazelwood mine fire</a>, bushfire and <a href="https://www.mja.com.au/journal/2016/205/9/rapid-assessment-impact-hazard-reduction-burning-around-sydney-may-2016">hazard reduction burns</a>, <a href="http://www.abc.net.au/news/2014-07-28/company-orica-fined-over-chemical-spills-and-safety-breaches/5629974">toxic chemical leaks</a>, infectious disease outbreaks and pandemics should prompt us to ask whether the health protection afforded to Australians is as good as it could be.</p>
<p>At first glance, this thunderstorm asthma seems like a freak event, an unavoidable act of nature caused by a combination of stormy weather breaking down pollen particles into pieces small enough to inhale, triggering an asthma response.</p>
<p>However, this is the not the first such event that has occurred in the world, in Australia or even in Melbourne.</p>
<p>So, how is it that <a href="http://www.jacionline.org/article/S0091-6749(07)01381-4/abstract">valuable lessons</a> learned from previous events were not applied in Melbourne? And how could <a href="https://www.researchgate.net/publication/292646960_Thunderstorm_related_asthma_in_South-Eastern_Australia_-_Recent_findings_and_asthma_epidemic_forecasting_possibilities">we plan</a> for future thunderstorm asthma events to avoid more people suffering the same fate?</p>
<h2>Learning from past events</h2>
<p>It’s nearly 20 years since Wagga Wagga in New South Wales had a similar severe event. After a series of investigations, we identified who was at risk, how it occurred and how common this was.</p>
<p>We found <a href="http://erj.ersjournals.com/content/16/1/3.long">nearly everyone</a> (96%) who was affected by thunderstorm asthma was allergic to rye grass pollen and had a history of hay fever. Just over one-third of people affected had never had asthma before, and very few (17%) were taking preventer medications for asthma. </p>
<p>Unlike medications taken to relieve the immediate symptoms of an attack (like Ventolin), people take preventer medications (known as inhaled corticosteroids) to control the underlying disease. There are good reasons to believe this class of medications, taken regularly, would protect against attacks induced by exposure to allergens.</p>
<p>We showed <a href="http://thorax.bmj.com/content/56/6/468.long">thunderstorm outflows</a> trigger these episodes during the pollen season by sweeping up pollen grains, rupturing them to release tiny allergenic particles and concentrating these close to the ground. </p>
<p>People who are allergic to pollen and are in the path of the thunderstorm outflow are likely to inhale air heavily loaded with these tiny pollen allergen-containing particles and, consequently, to experience narrowing of the airways and severe symptoms of asthma.</p>
<p>We also found thunderstorm asthma is <a href="http://thorax.bmj.com/content/56/6/468.long">quite common</a>. During late spring and summer, nearly half of all epidemics of asthma in six towns in inland New South Wales were associated with thunderstorm outflows.</p>
<p>As a result of these findings, public health, clinical and <a href="https://www.researchgate.net/publication/292646960_Thunderstorm_related_asthma_in_South-Eastern_Australia_-_Recent_findings_and_asthma_epidemic_forecasting_possibilities">meteorological</a> authorities in southern New South Wales worked together to reduce the risk of future episodes.</p>
<p>They ran a health promotion campaign to advise “at risk” people – people who “wheeze and sneeze” during spring – to use preventer medications for asthma during spring. The Bureau of Meteorology, working through the health service, also alerted hospitals and other health service providers when a thunderstorm outflow was predicted during spring and summer so they could prepare for the influx of patients.</p>
<p>This is effective health protection. It should have been applied throughout the regions of Australia affected by rye grass pollen and spring-time thunderstorms that are at risk for these events, but it wasn’t. Why?</p>
<h2>We need a national approach</h2>
<p>We don’t have a national health protection agency in Australia. Such agencies exist in many other countries (for example, the US has the <a href="http://www.cdc.gov/">Centers for Disease Control and Prevention</a> and the UK has <a href="https://www.gov.uk/government/organisations/public-health-england">Public Health England</a>).</p>
<p>In Australia, responsibility for health protection lies with the states and territories. Can we afford this degree of disaggregation of responsibility? The recent episode suggests we can’t.</p>
<p>We need a national agency to ensure the lessons learnt in one part of Australia are available throughout the country. As a nation, we’re too small to afford the level of knowledge and expertise required to give high quality health protection in eight separate jurisdictions. </p>
<p>Environmental hazards don’t generally recognise borders. Having agencies whose responsibilities ends at a line on the map makes no sense in dealing with problems like this. </p>
<p>There are other limitations to our health protection regimen in Australia. Effective action to protect health requires integration of expertise in:</p>
<ul>
<li>identifying and measuring hazards (environmental, toxicological and microbiological)</li>
<li>clinical medicine to diagnose and care for sick individuals</li>
<li>health service management (including primary and other ambulatory care, hospitals and ambulance services)</li>
<li>epidemiology, surveillance and monitoring</li>
<li>public health</li>
<li>research capacity.</li>
</ul>
<p>A national health protection agency also needs regulatory powers. Although these all exist in Australia they are not well integrated for health protection.</p>
<p>The lack of national health protection agency means state and territory health departments have to do the best they can, often with very limited resources and expertise. Although no-one can guarantee the disastrous consequences of the Melbourne thunderstorm could have been prevented, a well-resourced national health protection agency would’ve given us a better chance of planning and implementing effective mitigating actions, such as those implemented around Wagga after 1997. </p>
<p>The <a href="http://www.coaghealthcouncil.gov.au/AHMAC/Introduction">Australian Health Ministers Advisory Council</a> needs to set up, adequately resource, and empower a national health protection agency responsible for preventing or mitigating tragedies such as the Melbourne thunderstorm asthma epidemic.</p><img src="https://counter.theconversation.com/content/69426/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Guy Marks receives funding from NHMRC, ARC, Asthma Foundation of NSW</span></em></p>Melbourne’s recent thunderstorm asthma event caught services by surprise. So, is it time for a national health protection agency to coordinate our public health response?Guy B. Marks, Professor of Respiratory Medicine, South Western Sydney Clinical School, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/692162016-11-25T04:40:44Z2016-11-25T04:40:44ZWe could’ve seen thunderstorm asthma coming and there are ways to prepare<figure><img src="https://images.theconversation.com/files/147469/original/image-20161124-15351-r4dyeh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This event wasn't unprecedented, and we could've seen it coming.</span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p>A <a href="http://www.abc.net.au/news/2016-11-23/thunderstorm-asthma-student-days-away-from-graduating/8048894">fourth death</a> has been attributed to Melbourne’s “thunderstorm asthma” emergency on Monday night, and it was lucky there were not more, according to the state’s <a href="http://www.abc.net.au/news/2016-11-23/thunderstorm-asthma-student-days-away-from-graduating/8048894">health minister</a>. More than 2,000 people suffered breathing problems when a severe storm combined with an extreme pollen count to cause what is being described as “thunderstorm asthma”.</p>
<p>The recent severe thunderstorm in Melbourne caused hospitals across the city to be put on emergency alert as thousands of people called ambulance services, reporting severe breathing difficulties. Emergency departments were overwhelmed, with the patient overflow having to be directed to day units.</p>
<h2>What we know about thunderstorm asthma</h2>
<p>Asthma epidemics associated with sudden changes in weather are well documented globally, especially in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1021011/">Europe</a>, <a href="https://www.ncbi.nlm.nih.gov/pubmed/2862383">Australia</a> and <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(83)90718-3/abstract">North America</a>. </p>
<p>Interestingly, <a href="https://www.ncbi.nlm.nih.gov/pubmed/2862383">different causes</a> have been ascribed to the sudden outbreak of severe asthma. <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(83)90718-3/abstract">Considerable research effort</a> was put into investigating the cause of these outbreaks in the 1970s and ‘80s. </p>
<p>Pollution, a high pollen count, soybean offloading, fungal spores, copper sulphate and powdered sugar were all implicated, with changes in temperature and humidity <a href="https://www.ncbi.nlm.nih.gov/pubmed/17156336">being the common factors</a>. Melbourne in particular has had <a href="https://www.ncbi.nlm.nih.gov/labs/articles/1603007/">several well-documented</a> thunderstorm-related asthma epidemics.</p>
<p>Research effort around the world was initially focused on whether there was a single dominant cause of asthma epidemics during a severe thunderstorm (weather event). However, it is now very clear the causes are location-specific. </p>
<p>Thus, the <a href="https://www.ncbi.nlm.nih.gov/labs/articles/1603007/">cause of an asthma epidemic</a> during a thunderstorm in Melbourne may not be the same as the cause of an asthma epidemic during a thunderstorm in <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(85)90511-2/abstract">Birmingham</a>, United Kingdom. </p>
<p>Having said that, high winds and rain in the context of high levels of air allergens cause asthma epidemics. But the specific allergen responsible may be different.</p>
<h2>Could we have seen this coming?</h2>
<p>There are <a href="http://onlinelibrary.wiley.com/doi/10.1111/cea.12709/full">many common threads</a> in all reports of thunderstorm-related asthma – a high concentration of <a href="https://www.ncbi.nlm.nih.gov/pubmed/17156336">potentially allergenic material</a> such as that in late spring in Melbourne (pollen grains or fungi), a thunderstorm that sweeps up the allergens, which burst when wet and <a href="http://www.jacionline.org/article/S0091-6749(07)01381-4/abstract">release very small particles</a> (such as starch granules or fungal spores).</p>
<p>The high level of these small particles that can travel deep into our lungs induces severe asthma attacks in sensitive individuals. Keeping an eye on pollen counts and any forecasts of turbulent weather will prepare you for possible asthma attacks.</p>
<h2>What can we do to avoid them?</h2>
<p>There are many actions we can take to minimise the risk of weather-related asthma attacks. The main idea is to keep out of the way of allergens. So, stay indoors during rain and wind periods, especially the first 30-60 minutes when the allergens are most prevalent. </p>
<p>Taking your asthma medication (as prescribed by your GP) during a thunderstorm even if you are not feeling unwell <a href="https://www.ncbi.nlm.nih.gov/pubmed/10933077">may prevent or reduce the severity</a> of the asthma attack.</p>
<p>Hayfever treatments such as antihistamine tablets and steroid nasal sprays may provide some relief. These are most useful if taken prior to an expected thunderstorm. However, as thunderstorm asthma is due to allergens reaching the lower parts of the lung and nasal sprays target the nose, you may still get an asthma attack.</p>
<p>As the small allergen particles generated in thunderstorms are very easily and quickly able to penetrate deep into the lungs, these asthma attacks can progress very quickly; call 000 if you feel the beginnings of an attack.</p>
<p>If you have trouble breathing during a spring storm, even if you do not have asthma, call 000 for help. Many of those reporting to the emergency department in Melbourne did not have any pre-existing asthma. This suggests if you have a predisposition towards allergy, the allergens generated by a storm have a <a href="https://www.ncbi.nlm.nih.gov/pubmed/17156336">high probability of causing</a> a respiratory event.</p>
<p>This doesn’t mean hayfever sufferers should be using long-term asthma medications such as daily preventative puffer medications. One can get an asthma attack during a severe thunderstorm even without any previous indications of asthma, and as this is probably a rare occurrence it is not necessary to take daily medication.</p>
<p>Keep updated on local pollen counts and weather forecasts, especially in spring; keep your asthma medication up to date; enjoy the spectacle of the thunderstorm from inside your house; and call 000 if your asthma worsens or you feel any breathing difficulty.</p><img src="https://counter.theconversation.com/content/69216/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Reena Ghildyal has received funding from the National Health and Medical Research Council. </span></em></p>The recent severe thunderstorm in Melbourne caused hospitals across the city to be put on emergency alert as thousands of people called ambulance services, reporting severe breathing difficulties.Reena Ghildyal, Associate Professor in Biomedical Sciences, University of CanberraLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/340002014-11-16T19:16:46Z2014-11-16T19:16:46ZHay fever survival guide: why you have it and how to treat it<figure><img src="https://images.theconversation.com/files/64452/original/bvstb8yy-1415854887.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Antihistamines are the first-line treatment for those with mild or occasional hay fever.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/97481684@N08/13397331035">Tina Franklin/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Three million Australian adults – <a href="http://www.aihw.gov.au/allergic-rhinitis/">15% of the population</a> – struggle through spring and summer with watery eyes, running nose, itchy throat and the hallmark hay fever symptom, sneezing. </p>
<p>When people with hay fever are exposed to particular pollens, their body mistakenly thinks this is a threat and triggers an allergic reaction. Inflammatory cells quickly release mediators such as histamine and that’s when the symptoms kick in. </p>
<p>In some people with hay fever, pollen allergens can trigger allergic symptoms in the lower airways as well as the nose, making it difficult to breathe. Under certain climatic conditions, such as <a href="http://www.ncbi.nlm.nih.gov/pubmed/11359963">after thunderstorms</a>, pollen allergy can trigger asthma attacks, even in those <a href="https://theconversation.com/explainer-what-is-thunderstorm-asthma-4159">without a history</a> of asthma. </p>
<p>Hay fever can have a profound effect on our ability to function normally. The problem seems to be getting worse, or at least consumers are increasingly looking to alleviate their symptoms. In the ten years to 2010, the wholesale turnover of drugs to treat hay fever <a href="http://www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=10737420519">doubled</a>. </p>
<h2>Why you have it</h2>
<p>Grass pollens are the major outdoor allergen trigger for hay fever in Australia. The timing and severity of the grass pollen season varies considerably between years and <a href="http://www.aceas.org.au/index.php?option=com_content&view=article&id=113:australian-aerobiology&catid=35:working-groups&Itemid=174">places</a>, according to a recent analysis of 17 sites across Australia and New Zealand.</p>
<p>With a temperate climate, Melbourne usually has a short but intense grass pollen season, peaking late in spring (October to November). In Hobart, the grass pollen season peaks slightly later and the pollen load is low. </p>
<p>In contrast, Brisbane and Darwin have grass pollen seasons extending most of the year, with peaks in summer for Brisbane (January to March) and in the dry season in Darwin (May and June). </p>
<p>Adelaide, Sydney and Canberra have the temperate grass pollen season in spring but also have secondary peaks in summer. These late summer peaks in grass pollen are likely to be due to subtropical species. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/64455/original/7gccnrdz-1415856298.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/64455/original/7gccnrdz-1415856298.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/64455/original/7gccnrdz-1415856298.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/64455/original/7gccnrdz-1415856298.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/64455/original/7gccnrdz-1415856298.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/64455/original/7gccnrdz-1415856298.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/64455/original/7gccnrdz-1415856298.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">Levels of airborne pollen are influenced by weather and pollen production.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/38771399@N04/4416366355">Juan Ojeda/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>Australia is yet to establish a standardised network to monitor the timing and magnitude of pollen exposure. Levels of airborne pollen are influenced by weather and other factors affecting pollen production. Predictions of airborne pollen in the absence of actual pollen counts are therefore inaccurate and unhelpful. </p>
<p>Beyond biology, location and flowering times, patients with hay fever in Australia also show <a href="http://www.ncbi.nlm.nih.gov/pubmed/21231976">region-dependent patterns</a> of allergic responses to <a href="http://www.ctajournal.com/content/2/1/4">subtropical</a> and temperate grass pollens. This can affect the diagnosis and treatment of grass pollen allergy in Australia and elsewhere.</p>
<h2>How to manage your symptoms</h2>
<p>A number of oral medications, nasal sprays and eye drops to treat hay fever are available over the counter at pharmacies. They work in different ways and have different pros and cons. </p>
<p>Antihistamines have been used to manage hay fever for decades and can be the first-line treatment for those with mild or occasional hay fever. When you can predict exposure to an allergen, such as when lawn mowing or going on a picnic in spring, taking an antihistamine before the exposure will provide better protection. They are also safe to use in the long term. </p>
<p>Opt for the newer, non-sedating varieties of antihistamines. The older drugs, which are still available, cause drowsiness and have been shown to contribute to workplace accidents in adults and impaired learning in children. </p>
<p>Antihistamines in general are good for itching, sneezing and watering symptoms, but do not relieve nasal blockage very well. Decongestant tablets and sprays can do this job, but they are limited to relieving symptoms only and do not resolve the underlying inflammation. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/64454/original/68j2rq42-1415856100.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/64454/original/68j2rq42-1415856100.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/64454/original/68j2rq42-1415856100.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/64454/original/68j2rq42-1415856100.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/64454/original/68j2rq42-1415856100.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/64454/original/68j2rq42-1415856100.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/64454/original/68j2rq42-1415856100.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">Some people with hay fever have troublesome eye symptoms, usually itching, watering and redness.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/nub/5467820826">Andrew Goloida/Flkickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Overuse of decongestant nasal sprays can lead to longer-term problems with nasal blockage, so limit their use to a few days only.</p>
<p>For people with moderate to severe and persistent symptoms of hay fever, the most effective medications are the <a href="http://www.patient.co.uk/health/steroid-nasal-sprays">intranasal steroid sprays</a>. The older ones are now over-the-counter items and others are available by prescription. </p>
<p>These sprays have a “preventative” action and are most effective when use begins before the pollen season. If not, they will start relieving symptoms after a few days. The sprays must be used every day during the season to allow the best chance of success and to minimise side effects in the nose. They have also been shown to reduce allergic eye symptoms. </p>
<p>Some people worry that these are “steroid” sprays, but they differ greatly from traditional oral steroids. The modern topical steroid sprays are barely absorbed into the body and don’t have the much-feared muscle-building steroid side effects. A small percentage of people will experience some nasal bleeding, even if using the spray correctly; this is the most common side effect.</p>
<p>A number of people with hay fever will have troublesome eye symptoms, usually itching, watering and redness. If this isn’t relieved with topical nasal sprays, topical antihistamine eye drops can be very effective. Rinsing the eyes with an artificial tear solution of saline fluid can also be very soothing. </p>
<p>For people with severe and prolonged symptoms or who can’t gain adequate control with available medications, <a href="http://www.allergy.org.au/patients/allergy-treatment/immunotherapy">allergen-specific immunotherapy</a> is available. This should be prescribed by an allergy specialist who determines the correct “vaccine” for the therapy. The immunotherapy program may extend over three to four years and is the only therapy that can provide long-lived benefit.</p>
<p>If you suffer from regular hay fever symptoms and medications don’t seem to be working, talk to your doctor. They can help guide you to the safest and most effective treatment option.</p><img src="https://counter.theconversation.com/content/34000/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Janet Davies receives funding from the National Health and Medical Research Council, The University of Queensland and The Princess Alexandra Hospital Foundation. She has consults to Stallergenes Pty Ltd and has received Honorarium from Glaxo Smith Kline and in kind research support from ThermoFisher (Sweden) and Sullivan Nicolaides Pathology (Australia). The Australian Aerobiology Working Group was supported by the Australian Center for Ecological Analysis and Synthesis and co-sponsored by untied funds from Merck Sharp and Dohme.</span></em></p><p class="fine-print"><em><span>Connie Katelaris has received honoraria from Meda and also Stallergenes for giving lectures.</span></em></p>Three million Australian adults – 15% of the population – struggle through spring and summer with watery eyes, running nose, itchy throat and the hallmark hay fever symptom, sneezing. When people with…Janet Davies, Senior Research Fellow, Lung and Allergy Research Centre, The University of QueenslandConnie Katelaris, Professor of Immunology and Allergy, UWAS & Head of Unit, South Western Sydney Local Health DistrictLicensed 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/41592011-11-07T03:20:36Z2011-11-07T03:20:36ZExplainer: what is thunderstorm asthma?<figure><img src="https://images.theconversation.com/files/5221/original/Brandon_LLW.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">High pollen counts, warm weather and storms are the perfect conditions for thunderstorm asthma.</span> <span class="attribution"><span class="source">Brandon LLW</span></span></figcaption></figure><p>If you suffer from itchy eyes, a runny nose, headaches and excessive sneezing this time of year, you’re certainly not alone. Hay fever or <a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Hayfever?open">allergic rhinitis</a> is an allergic reaction to pollen and affects <a href="http://www.abs.gov.au/AUSSTATS/abs@.nsf/0/9B34B8C8BF2FDA34CA25773700169C83?opendocument">one in six Australians</a>. </p>
<p>But when you combine high pollen counts with thunderstorms and warm weather, a much more serious phenomenon can unfold: thunderstorm asthma attacks. </p>
<p>Grass pollen is usually too large to enter the small airways of the lungs and is filtered out by the nose, causing hay fever in those allergic to pollen. </p>
<p>But stormy winds and moisture can cause the pollen to rupture into tiny particles, which are small enough to be inhaled. </p>
<p>The outflow winds of a thunderstorm then concentrate these tiny particles at ground level, where they can easily enter the small airways of the lungs and cause an acute asthma attack in those who are allergic to grass pollens.</p>
<p>The symptoms of thunderstorm asthma can occur quickly and include shortness of breath, chest tightness, coughing and wheezing.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/5222/original/Peet_Sneekes.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/5222/original/Peet_Sneekes.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/5222/original/Peet_Sneekes.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/5222/original/Peet_Sneekes.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/5222/original/Peet_Sneekes.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/5222/original/Peet_Sneekes.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/5222/original/Peet_Sneekes.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Stoms cause pollen to rupture into tiny particles, which can be inhaled into the lungs.</span>
<span class="attribution"><span class="source">Peet Sneekes</span></span>
</figcaption>
</figure>
<h2>Who does it affect?</h2>
<p>Thunderstorm asthma <a href="http://www.ncbi.nlm.nih.gov/pubmed/15283882">commonly affects</a> young adults with a history of hay fever but not necessarily of asthma. And of those with a previous diagnosis of asthma, many claimed it wasn’t severe enough to warrant preventer medication. </p>
<p>After the Wagga Wagga thunderstorm asthma epidemic in October 1997, <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1746065/">researchers compared</a> the data of those who experienced a thunderstorm asthma attack with those who had an asthma attack on other days of the year (the control group). They found that 95% of those affected by thunderstorm asthma had a history of hay fever and 96% tested positive to grass pollen allergies. </p>
<p>Of those with a history of asthma, only one in four (27%) of affected cases were taking regular preventer inhalers compared with more than half (56%) of the control group.</p>
<p>This suggests that regular use of asthma preventer medication, at least during spring, may protect those with asthma and grass allergies from thunderstorm asthma attacks. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/5224/original/AAP_ambulance.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/5224/original/AAP_ambulance.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/5224/original/AAP_ambulance.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/5224/original/AAP_ambulance.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/5224/original/AAP_ambulance.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/5224/original/AAP_ambulance.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/5224/original/AAP_ambulance.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">Symptoms can be sudden and severe.</span>
<span class="attribution"><span class="source">AAP</span></span>
</figcaption>
</figure>
<h2>How is it treated? </h2>
<p>The best way to treat thunderstorm asthma is to prevent it occurring, where possible. So good asthma control is essential. </p>
<p>Anyone with asthma who has allergy symptoms in spring (including hay fever, or worsened asthma symptoms) should use a regular preventer inhaler, even if they feel well. These inhalers are designed to reduce the inflammation in the lungs over a period of time, and prevent an asthma attack occurring. </p>
<p>All asthma sufferers should have a written action plan from their doctor, which describes the steps to be taken if symptoms escalate. </p>
<p>In the event of a thunderstorm asthma attack, treatment will be the same as any other acute asthma attack, which usually involves the administration of inhaled mediation to dilate the airways, plus an anti-inflammatory medication. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/5223/original/ktpupp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/5223/original/ktpupp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/5223/original/ktpupp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/5223/original/ktpupp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/5223/original/ktpupp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/5223/original/ktpupp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/5223/original/ktpupp.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">Thunderstorm asthma affects those with a history of hay fever.</span>
<span class="attribution"><span class="source">Flickr/ktupp</span></span>
</figcaption>
</figure>
<h2>What regions are affected?</h2>
<p>Thunderstorm asthma was first described in Melbourne in 1987 and has occurred in other parts of the country (south-eastern Australia is particularly vulnerable) and the world, including in England and Italy. </p>
<p>The most recent epidemic occurred in Melbourne on 25 November 2010 after the onset of a thunderstorm, when grass pollen counts were in the extreme range. </p>
<p>Shortly after the thunderstorm began, the Melbourne metropolitan ambulance service was inundated with calls for assistance from people who had trouble breathing and the ambulance disaster management plan was enacted. </p>
<p>Austin Health, a large metropolitan hospital in Melbourne, saw a tenfold increase in patients presenting with acute asthma attacks in the 24 hour period following the storm. </p>
<p>Thunderstorm epidemics are uncommon but the prospect of another wet spring/summer means we need to be vigilant. If you have difficulty breathing – whether you have a history of asthma or not – call 000 for an ambulance immediately.</p>
<p><br>
<em>See more <a href="https://theconversation.com/pages/explainer">Explainer articles</a> on The Conversation.</em></p><img src="https://counter.theconversation.com/content/4159/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Megan Howden 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>If you suffer from itchy eyes, a runny nose, headaches and excessive sneezing this time of year, you’re certainly not alone. Hay fever or allergic rhinitis is an allergic reaction to pollen and affects…Megan Howden, Advanced trainee in respiratory medicine, Austin HealthLicensed as Creative Commons – attribution, no derivatives.