tag:theconversation.com,2011:/us/topics/peanut-allergy-8780/articlesPeanut allergy – The Conversation2023-04-06T06:11:50Ztag:theconversation.com,2011:article/2028482023-04-06T06:11:50Z2023-04-06T06:11:50ZHere’s why having chocolate can make you feel great or a bit sick – plus 4 tips for better eating<figure><img src="https://images.theconversation.com/files/518983/original/file-20230403-20-jmdrkw.jpg?ixlib=rb-1.1.0&rect=17%2C17%2C5879%2C3907&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/delicious-easter-holiday-chocolate-bunny-eggs-1661076946">Shutterstock</a></span></figcaption></figure><p>Australians are <a href="https://www.retail.org.au/media/sweet-spending-boon-predicted-for-easter-retail">predicted</a> to spend around A$1.7 billion on chocolates, hot cross buns and other special foods this Easter season. </p>
<p>Chocolate has a long history of production and consumption. It is made from cacao beans that go through processes including fermentation, drying, roasting and grounding. What is left is a rich and fatty liquor that is pressed to remove the fat (cocoa butter) and the cacao (or “cocoa”) powder which will then be mixed with different ingredients to produce dark, milk, white and other types of chocolates. </p>
<p>There are several health benefits and potential problems that come in these sweet chocolatey packages. </p>
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Read more:
<a href="https://theconversation.com/at-chocolate-time-weve-discovered-what-the-brands-that-score-best-on-child-labour-and-the-environment-have-in-common-201682">At chocolate time, we've discovered what the brands that score best on child labour and the environment have in common</a>
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<h2>The good news</h2>
<p>Cacao beans contain <a href="https://foodstruct.com/food/cocoa-bean">minerals</a> like iron, potassium, magnesium, zinc and phosphorus and some vitamins. They are also rich in beneficial chemicals called <a href="https://pubmed.ncbi.nlm.nih.gov/23150750/">polyphenols</a>. </p>
<p>These are great antioxidants, with the potential to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5465250/">improve heart health</a>, increase <a href="https://pubmed.ncbi.nlm.nih.gov/25164923/">nitric oxide</a> (which dilates blood vessels) and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3488419/">reduce blood pressure</a>, provide food for gut microbiota and <a href="https://www.mdpi.com/2072-6643/12/7/1908">promote gut health</a>, boost the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5465250/">immune system</a> and reduce inflammation. </p>
<p>However, the concentration of polyphenols in the chocolate we eat depends largely on the cocoa solid amounts used in the final product. </p>
<p>In general terms, the darker the chocolate, the more cocoa solids, minerals and polyphenols it has. For example, dark chocolates may have around <a href="https://www.tandfonline.com/doi/full/10.1080/10942912.2011.614984">seven times more polyphenols</a> compared to white chocolates and <a href="https://www.tandfonline.com/doi/full/10.1080/10942912.2011.614984">three times more polyphenols</a> compared to milk chocolates. </p>
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<a href="https://images.theconversation.com/files/518984/original/file-20230403-18-cku8bq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="selection of dark chocolate squares" src="https://images.theconversation.com/files/518984/original/file-20230403-18-cku8bq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/518984/original/file-20230403-18-cku8bq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/518984/original/file-20230403-18-cku8bq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/518984/original/file-20230403-18-cku8bq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/518984/original/file-20230403-18-cku8bq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/518984/original/file-20230403-18-cku8bq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/518984/original/file-20230403-18-cku8bq.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">Dark chocolate is less likely to give you problems.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/broken-slices-chocolate-close-564089023">Shutterstock</a></span>
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Read more:
<a href="https://theconversation.com/health-check-the-good-and-bad-of-easter-eggs-chocolate-and-hot-cross-buns-37920">Health Check: the good and bad of Easter eggs, chocolate and hot cross buns</a>
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<h2>But also some bad news</h2>
<p>Unfortunately, the <a href="https://theconversation.com/treat-or-treatment-chocolate-is-good-but-cocoa-is-better-for-your-heart-3084">health benefits of cocoa solids</a> are easily offset by the high sugar and fat content of modern-day chocolates. For example, milk and white chocolate eggs are on average 50% sugar, 40% fat (mostly saturated fats) – which means a lot of added kilojoules (calories). </p>
<p>Also, there may be some side effects that come with ingesting chocolate. </p>
<p>Cocoa beans include a compound called theobromine. While it has the anti-inflammatory properties responsible for some of the health benefits of chocolate, it is also a mild brain stimulant that acts in a similar way to caffeine. The mood boost it offers may also be partly responsible for how much we <a href="https://www.frontiersin.org/articles/10.3389/fphar.2015.00030/full?crsi=662496658&cicada_org_src=healthwebmagazine.com&cicada_org_mdm=direct">like chocolate</a>. Dark chocolate has higher theobromine compared to milk and white chocolate. </p>
<p>But accordingly, overindulging in chocolate (and therefore theobromine) may lead to feeling restless, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3672386/">headaches</a> and nausea. </p>
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Read more:
<a href="https://theconversation.com/whats-the-white-stuff-on-my-easter-chocolate-and-can-i-still-eat-it-181274">What's the white stuff on my Easter chocolate, and can I still eat it?</a>
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<h2>What else is in your chocolate?</h2>
<p>Milk and dairy-based chocolates may also cause stomach upset, abdominal pain and bloating in people with <a href="https://dietitiansaustralia.org.au/health-advice/lactose-intolerance">lactose intolerance</a>. This happens when we don’t produce enough lactase enzymes to digest milk sugar (lactose). </p>
<p>People with lactose intolerance can usually tolerate up to 6 grams of lactose without showing symptoms. Milk chocolate can have around <a href="https://www.ncbi.nlm.nih.gov/books/NBK310258/">3 grams of lactose</a> per 40 grams (the size of a standard chocolate bar). So two chocolate bars (or the equivalent in milk chocolate eggs or bunnies) may be enough to cause symptoms. </p>
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<a href="https://images.theconversation.com/files/518981/original/file-20230403-24-w2xk2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="little girl with bunny ears on and chocolate on face" src="https://images.theconversation.com/files/518981/original/file-20230403-24-w2xk2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/518981/original/file-20230403-24-w2xk2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/518981/original/file-20230403-24-w2xk2p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/518981/original/file-20230403-24-w2xk2p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/518981/original/file-20230403-24-w2xk2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/518981/original/file-20230403-24-w2xk2p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/518981/original/file-20230403-24-w2xk2p.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">Lactose sensitivities tend to increase with age.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/little-blond-girl-dirty-chocolate-bunny-1937877997">Shutterstock</a></span>
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<p>It’s worth noting that lactase enzyme activity dramatically declines as we age, with the highest activity in newborns and children. So lactose sensitivity or intolerance may not be such an issue for your kids and your symptoms may increase over time. Genetics also plays a major role in how sensitive people are to lactose.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6815241/">Allergic reactions</a> to chocolate are usually due to the added ingredients or cross-contamination with potential allergens such as nuts, milk, soy, and some sweeteners used in the production of chocolate. </p>
<p>Symptoms can be mild (acne, rashes and stomach pain) or more severe (swelling of the throat and tongue and shortness of breath). </p>
<p>If you or your family members have known allergic reactions, make sure you read the label before indulging – especially in a whole block or basket of the stuff. And if you or your family members do experience symptoms of an allergic reaction after eating chocolate, <a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/allergic-reactions-emergency-first-aid">seek medical attention</a> immediately.</p>
<h2>4 take home tips</h2>
<p>So, if you are like me and have a weakness for chocolate there are a few things you can do to make the experience a good one.</p>
<ol>
<li>keep an eye out for the darker chocolate varieties with higher cocoa solids. You may notice a percentage on labelling, which refers to how much of its weight is from cocoa beans. In general, the higher this percentage, the lower the sugar. White chocolate has almost no cocoa solid, and mostly cocoa butter, sugar and other ingredients. Dark chocolate has 50–100% cocoa beans, and less sugar. Aim for at least 70% cocoa<br></li>
<li>read the fine print for additives and possible cross-contamination, especially if allergies might be an issue</li>
<li>the ingredients list and nutrition information panel should tell you all about the chocolate you choosing. Go for varieties with lower sugar and less saturated fat. Nuts, seeds and dried fruits are better ingredients to have in your chocolate than sugar, creme, syrup, and caramel<br></li>
<li>finally, treat yourself – but keep the amount you have within sensible limits! </li>
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Read more:
<a href="https://theconversation.com/the-history-of-chocolate-when-money-really-did-grow-on-trees-196173">The history of chocolate: when money really did grow on trees</a>
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<p class="fine-print"><em><span>Dr Khalesi is supported by a Postdoctoral Fellowship (Award No. 102584) from the National Heart Foundation of Australia.</span></em></p>Good things can come in chocolatey packages, but read the fine print if you want to avoid potential side effects of eating Easter treats.Saman Khalesi, Postdoctoral Fellow of the National Heart Foundation & Senior Lecturer and Discipline Lead in Nutrition, School of Health, Medical and Applied Sciences, CQUniversity AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1380902020-05-27T17:14:29Z2020-05-27T17:14:29ZPeanuts, eggs and your baby: How to introduce food allergens during the coronavirus pandemic<figure><img src="https://images.theconversation.com/files/337093/original/file-20200522-124826-1wdo67v.jpg?ixlib=rb-1.1.0&rect=49%2C0%2C5193%2C3637&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Recommendations suggest babies be introduced to food allergens around age six months.</span> <span class="attribution"><span class="source">(Pixabay)</span></span></figcaption></figure><p>The best way to prevent food allergies is to introduce the most common allergenic foods to babies early in life, as <a href="https://www.doi.org/10.1001/jama.2016.12623">research evidence for peanut and egg has shown</a>. Even during the current COVID-19 pandemic, the benefits of allergy prevention outweigh the very small risk of a severe reaction.</p>
<p>As clinicians and researchers in the field of allergy and infant nutrition, we are worried that COVID-19 may lead parents to delay the introduction of allergens to their babies. Parents may not feel comfortable taking their baby to an emergency room because of potential exposure to COVID-19, so they don’t want to risk a severe allergic reaction requiring a hospital visit.</p>
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<img alt="" src="https://images.theconversation.com/files/335092/original/file-20200514-77243-1yqe5xr.jpg?ixlib=rb-1.1.0&rect=31%2C146%2C3463%2C2551&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/335092/original/file-20200514-77243-1yqe5xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=463&fit=crop&dpr=1 600w, https://images.theconversation.com/files/335092/original/file-20200514-77243-1yqe5xr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=463&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/335092/original/file-20200514-77243-1yqe5xr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=463&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/335092/original/file-20200514-77243-1yqe5xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=582&fit=crop&dpr=1 754w, https://images.theconversation.com/files/335092/original/file-20200514-77243-1yqe5xr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=582&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/335092/original/file-20200514-77243-1yqe5xr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=582&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 most common food allergens are cow’s milk, eggs, peanuts and tree nuts, sesame seeds, fish and shellfish, soy and wheat.</span>
<span class="attribution"><span class="source">(Unsplash)</span></span>
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<p>The <a href="https://doi.org/10.1093/pch/pxy195">most recent Canadian recommendations</a> continue to apply during the COVID-19 pandemic. The recommendations encourage parents to introduce allergenic foods to babies as soon as they start eating solids around six months, but not before four months of age. This applies to lower-risk infants as well, but is especially important for babies who are at higher risk of allergy due to eczema, other food allergies or an immediate family history of an allergic condition. </p>
<h2>Should I delay introduction of allergens?</h2>
<p>Many parents may be wondering if they should hold off on introducing allergens to their baby because of COVID-19. The answer is no. Despite the pandemic and some families trying to avoid the risk of an emergency room visit, introducing allergens to babies <a href="https://www.cps.ca/en/blog-blogue/can-we-continue-to-recommend-early-allergenic-food-introduction-during-a-pandemic">without delay</a> is recommended. The risk of a severe allergic reaction when eating a new food for the first time <a href="http://www.doi.org/10.1056/NEJMoa1414850">is extremely low — well below two per cent</a>. </p>
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<img alt="" src="https://images.theconversation.com/files/337095/original/file-20200522-124832-13c5g6g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/337095/original/file-20200522-124832-13c5g6g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/337095/original/file-20200522-124832-13c5g6g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/337095/original/file-20200522-124832-13c5g6g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/337095/original/file-20200522-124832-13c5g6g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/337095/original/file-20200522-124832-13c5g6g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/337095/original/file-20200522-124832-13c5g6g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&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 risk of a severe allergic reaction to a new food is very low.</span>
<span class="attribution"><span class="source">(Unsplash)</span></span>
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<p>Delaying the introduction might put children at higher risk of allergies. If not introduced in infancy, the risk of an allergic reaction as a child gets older is increased, so it’s better to introduce early and not delay. There is evidence that in higher-risk infants, peanut introduction during infancy <a href="http://www.doi.org/10.1056/NEJMoa1414850">reduces the risk of peanut allergy by up to 80 per cent</a>.</p>
<h2>What if my baby has an anaphylactic reaction?</h2>
<p>It’s very unlikely that infants will react so severely to a new food that they will need an emergency trip to the hospital. To put it further into perspective, <a href="https://doi.org/10.1001/jama.2010.582">food allergies affect around two per cent to 10 per cent</a> of Canadians, so even most older children will not have an allergic reaction to foods. The chance of a severe allergic reaction such as anaphylaxis is much less than two per cent, even in higher risk infants.</p>
<p>In the unlikely event that infants have a severe reaction and need to go to the emergency room, <a href="https://doi.org/10.1016/j.jiph.2020.03.019">the risk of acquiring COVID-19 is also extremely low when proper infection control measures are adhered to</a>. The risk of an infant dying from COVID-19 in the unlikely event that it is acquired while visiting the emergency room is even more remote <a href="http://www.doi.org/10.1097/INF.0000000000002700">since children have milder disease symptoms</a>.</p>
<h2>How should I introduce allergens?</h2>
<p>In Canada, the most common allergens are cow’s milk, eggs, peanuts and tree nuts, sesame seeds, fish and shellfish, soy and wheat. Puréed foods, smooth nut butters diluted with breast milk or formula, or ground nuts mixed in purées are great ways for parents to introduce allergens safely in non-choking form for babies.</p>
<p>It’s important that the allergen be introduced orally, meaning that the infant eats the food. We don’t recommend rubbing it on the skin or lips to test for an allergic reaction as that may cause irritation that could be misinterpreted as allergy.</p>
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<span class="caption">Allergens can be introduced in puréed foods. Smooth peanut butter can be diluted with breast milk or formula.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>Parents can introduce these foods one at a time, always in an age-appropriate way for their baby, and without delays between the introduction of new foods. Allergic reactions usually appear very quickly, so parents can gauge reaction within a couple of hours following the meal. </p>
<p><a href="https://foodallergycanada.ca/food-allergy-basics/preventing-and-treating-allergic-reactions/reaction-signs-and-symptoms/">Allergic reactions in infants will usually affect</a> the skin (hives, itchiness, rash), gastrointestinal tract (vomiting, diarrhea) or respiratory system (wheezing). Parents should monitor the signs closely and take pictures of skin reactions as they seek advice from their family doctor. If there is a reaction, the food should be avoided until parents have consulted their health-care team, and decided on the next best steps to take. </p>
<p>Once an allergen has been introduced safely, it is very important to keep offering and serving it to the baby a few times a week to maintain tolerance. Aiming to include these allergens in the regular family diet is a practical way for parents to offer it often to baby. </p>
<p>The benefit of preventing the development of food allergy (which can affect the quality of life of the whole family for many years) is far greater in our professional opinion than the very small risk of experiencing a life-threatening allergic reaction and potentially exposing infants to COVID-19.</p><img src="https://counter.theconversation.com/content/138090/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Maude Perreault was a Vanier Scholar and received funding from the Canadian Institutes of Health Research, and the Canadian Child Health Clinician Scientist Program.</span></em></p><p class="fine-print"><em><span>Edmond S. Chan has received research support from DBV Technologies; has been a member of advisory boards for Pfizer, Pediapharm, Leo Pharma, Kaleo, DBV, AllerGenis; is a member of the healthcare advisory board for Food Allergy Canada; was an expert panel and coordinating committee member of the National Institute of Allergy and Infectious Diseases (NIAID)-sponsored Guidelines for Peanut Allergy Prevention; and was co-lead of the CSACI oral immunotherapy guidelines.</span></em></p><p class="fine-print"><em><span>Elissa Abrams is a member of theHealthcare advisory board for Food Allergy Canada. </span></em></p>Introducing food allergens early is the best way to prevent food allergies from developing. Even in a pandemic, the benefits outweigh the very small risk of a severe reaction requiring emergency care.Maude Perreault, Registered dietitian and Research Associate, McMaster UniversityEdmond S. Chan, Pediatric Allergist; Head & Clinical Associate Professor, Division of Allergy & Immunology, Department of Pediatrics, Faculty of Medicine; Investigator, BC Children's Hospital Research Institute, University of British ColumbiaElissa M. Abrams, Asssistant Professor, Department of Pediatrics, Section of Allergy and Clinical Immunology, University of Manitoba, Johns Hopkins UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1332952020-04-01T14:03:44Z2020-04-01T14:03:44ZPeanut allergy may start in the gut – opening up new ways to tackle it<figure><img src="https://images.theconversation.com/files/322622/original/file-20200324-155640-11bs8ma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/peanut-butter-sandwich-63361243">Shutterstock/JiriHera</a></span></figcaption></figure><p>Severe food allergies can be terrifying, both for the person affected and their loved ones. Allergies are <a href="https://www.ncbi.nlm.nih.gov/pubmed/20920770?dopt=Abstract">increasing</a> and affect between 3% and 6% of the <a href="https://www.ncbi.nlm.nih.gov/pubmed/21236480?dopt=Abstract">population</a>. But science has yet to fully grasp the reasons why. One theory – which appears to be backed up by the evidence of a <a href="https://www.ncbi.nlm.nih.gov/pubmed/32139586">new study</a> – is that the answer lies in the human gut. </p>
<p>More specifically, the antibodies produced in the human gut. Antibodies are an important part of our immune system that help us recognise and eliminate “foreign” antigens (proteins on the surface of a substance that triggers an immune response). Foreign antigens are found on viruses, bacteria and other things that may cause us harm, as well as the food we eat. </p>
<p>Antibodies are made by B-cells (a type of white blood cell called a <a href="https://www.bbc.co.uk/bitesize/guides/ztp9q6f/revision/4">lymphocyte</a>) which mature in the bone marrow before migrating to other parts of the body. Then the B-cells make antibodies in response to foreign antigens they meet. This new study suggests that B-cells can influence whether an immune response is too “strong” against peanut antigens, by producing too much of a type of antibody that encourages severe allergic reactions, and not producing enough of the antibodies that keep our bodies from overreacting in this way.</p>
<h2>Antibodies and allergies</h2>
<p>Humans produce five different types of antibodies or immunoglobulins (Ig) – IgA, IgM, IgG, IgD and IgE. IgE, which is known as the “allergy antibody”, mainly protects us against parasite infections, but it also helps to cause anaphylaxis – a serious, rapid allergic reaction that can cause an itchy rash, throat or tongue swelling, shortness of breath, vomiting and ultimately death. Anaphylaxis can occur in people who are allergic to peanuts as well as <a href="https://www.food.gov.uk/business-guidance/allergen-guidance-for-food-businesses">other foods</a>.</p>
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<p>IgE is usually the least abundant type of antibody, at only 0.05% of antibodies in the blood, but it can cause the most powerful of immune reactions. IgG is the most common antibody in the blood, at around 75%. IgG helps other immune cells to clear away dangerous material.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/32139586">Researchers</a> sequenced all the Ig antibody genes from B-cells in tissues from different organs of 19 people with a peanut allergy and compared them with those of non-allergic people. The results showed that more IgE-producing B-cells reside within the gut of those with allergies, compared with those who don’t. There were roughly equal numbers of B-cells in the blood and bone marrow of both groups, so it is the gut-residing B-cells that are different.</p>
<p>The report found that non-allergic people make more of the common IgG-type antibodies in response to peanut proteins than allergic people. These antibodies can neutralise the negative effect of the “allergic antibody” and therefore it may be that people with peanut allergies may not only produce too much IgE, but may not produce enough IgG.</p>
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Read more:
<a href="https://theconversation.com/curious-kids-if-you-have-lots-of-the-thing-youre-allergic-to-does-your-body-get-used-to-it-104881">Curious Kids: if you have lots of the thing you're allergic to, does your body get used to it?</a>
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<p>The research shows that gut tissue is a likely place for the development of the IgE allergy antibody in people who are allergic to peanuts. This makes sense because the gut is the site of vast quantities of foreign proteins, in the form of microflora (the microbes that live within us) and in the food we eat. But usually, people’s immune systems do not react to their gut contents because they have formed <a href="https://www.ncbi.nlm.nih.gov/pubmed/29338074">“tolerant” immune responses</a> early in life.</p>
<p>The timing of first exposure to proteins (of microbe or food origin) may be influencing how much <a href="https://www.ncbi.nlm.nih.gov/pubmed/28601684">IgE and IgG antibodies</a> are made. So if more allergic antibodies are made, then it renders that person “sensitive” (and more likely to be allergic), rather than tolerant. This is why immune <a href="https://www.ncbi.nlm.nih.gov/pubmed/24702950">tolerance training</a> through exposure to antigens while in the womb and early life, through proteins in the mother’s diet and her intestinal microflora, is particularly important.</p>
<p>An increasing <a href="https://www.ncbi.nlm.nih.gov/pubmed/30340391">body of evidence</a> supports the hypothesis that early antigen exposure increases tolerance and lowers risk of childhood food allergies and other diseases. Historically, pregnant women were advised to limit their intake of peanuts, as it was initially thought that consumption during pregnancy could increase the risk of an allergic child. </p>
<h2>Eating nuts during pregnancy</h2>
<p>Evidence now suggests that avoiding nuts during pregnancy may prevent the foetus being exposed to nut antigens in the womb, where tolerance starts to be developed, and therefore <a href="https://www.ncbi.nlm.nih.gov/pubmed/24366539">increase the risk</a> of an allergic child.</p>
<p>This hypothesis is also supported by recent evidence showing that intestinal microflora (of both mother and child) plays a major role <a href="https://www.ncbi.nlm.nih.gov/pubmed/27126036">in immune tolerance development</a>, both while in the womb and in early life. So eating nuts during pregnancy, or when breastfeeding, may reduce the risk of a child developing an allergy.</p>
<p>The new study also discovered that many people share similar peanut-reactive IgE DNA sequences, which was surprising as one person’s antibodies are usually different from another’s. </p>
<p>This suggests that IgE antibodies in different people recognise peanut proteins in a similar way, which could help scientists in developing drugs to neutralise the “allergic antibodies” that cause anaphylaxis. Such drugs could be taken before or after exposure to lessen the allergic reaction and prevent anaphylaxis. But it may be several years before this type of treatment is available.</p><img src="https://counter.theconversation.com/content/133295/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rachael Rigby does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Evidence from a new study could help scientists develop drugs to neutralise the ‘allergic antibodies’ that cause anaphylaxis.Rachael Rigby, Senior Lecturer in Gastro-Intestinal Health, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1304552020-02-24T01:04:00Z2020-02-24T01:04:00ZI think my child has outgrown their food allergy. How can I be sure?<figure><img src="https://images.theconversation.com/files/316106/original/file-20200219-11000-jdyvy.jpg?ixlib=rb-1.1.0&rect=0%2C1%2C1000%2C664&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/cute-little-asian-toddler-boy-holding-1551986915">Shutterstock</a></span></figcaption></figure><p>Some children grow out of their food allergies, but researchers don’t exactly know why.</p>
<p>Here’s how to work with your allergy specialist if you suspect your child isn’t allergic any more.</p>
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Read more:
<a href="https://theconversation.com/four-myths-about-allergies-you-thought-were-true-but-arent-42855">Four myths about allergies you thought were true – but aren't</a>
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<h2>Who’s more likely to grow out of their food allergy?</h2>
<p>Food allergy affects up to <a href="https://www.allergy.org.au/patients/food-allergy/food-allergy">10% of infants and 8% of children</a> in <a href="https://www.ncbi.nlm.nih.gov/pubmed/28260260">Australia and New Zealand</a>. Common food allergies in young children are egg, cow’s milk and peanut. Allergies to tree nuts, fish and seafood tend to be more common in adolescents.</p>
<p>Rates of food allergies <a href="https://www.allergy.org.au/patients/food-allergy/food-allergy">have increased</a> in children and adults in developed countries including Australia. There’s also an <a href="https://www.ncbi.nlm.nih.gov/pubmed/28260260">increase in the number</a> of children up to four years old who’ve been admitted to hospital with food anaphylaxis (a severe, life-threatening reaction).</p>
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Read more:
<a href="https://theconversation.com/introduce-eggs-and-peanuts-early-in-infants-diets-to-reduce-the-risk-of-allergies-65564">Introduce eggs and peanuts early in infants' diets to reduce the risk of allergies</a>
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<p>Yet, Australian research <a href="https://www.ncbi.nlm.nih.gov/pubmed/28514997">shows</a> almost all children (more than 80%) with an egg allergy outgrow their allergy by the time they are four years old, as do about 20% of children with a peanut allergy.</p>
<p>However, for others, food allergies are likely to persist. This is <a href="https://www.ncbi.nlm.nih.gov/pubmed/26968958">most likely</a> if they have eczema, hay fever and/or asthma alongside a <a href="https://www.jacionline.org/article/S0091-6749(18)32688-5/abstract">tree nut allergy from a young age</a>, or they have a <a href="https://www.ncbi.nlm.nih.gov/pubmed/26968958">severe allergic reaction to a low dose</a> of their particular food allergen.</p>
<h2>Why do they outgrow their food allergy?</h2>
<p>Researchers don’t know exactly why some children grow out of their food allergies. But their immune response to food allergens seems to change.</p>
<p>For instance, these children have <a href="https://www.ncbi.nlm.nih.gov/pubmed/28739336">lower levels</a> of antibodies you’d normally see as part of an allergic response (lower levels of allergen-specific IgE). They also have higher levels of other immune system components (allergen-specific IgG4, IL-10 and allergen-specific T cells).</p>
<p>Other research has focused on a type of T cell, called the <a href="https://www.ncbi.nlm.nih.gov/pubmed/30736894">regulatory T cell</a>, which regulates how the <a href="https://www.ncbi.nlm.nih.gov/books/NBK21070/">adaptive immune system</a> responds to antigens. </p>
<p>Children who are not allergic or have developed naturally occurring tolerance are more likely to have stable levels of these cells. However, children <a href="https://www.ncbi.nlm.nih.gov/pubmed/26456457">with an allergy</a> may not be able to regenerate these cells once exposed to the food allergen, so have lower levels.</p>
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Read more:
<a href="https://theconversation.com/explainer-what-is-the-immune-system-19240">Explainer: what is the immune system?</a>
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<p>Children who outgrow their food allergies may also have a <a href="https://www.ncbi.nlm.nih.gov/pubmed/30736894">dampened inflammatory response</a> in a part of their immune system known as the <a href="https://www.ncbi.nlm.nih.gov/books/NBK26846/">innate immune system</a>.</p>
<p>Lastly, changes in the diversity of <a href="https://www.ncbi.nlm.nih.gov/pubmed/27059726">gut microbiota</a> (microorganisms such as bacteria living in the gut) and substances made by these microbes may also be involved.</p>
<p>However, we need more research to verify what’s happening both in the immune system and the gut microbiome to be sure.</p>
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<strong>
Read more:
<a href="https://theconversation.com/essays-on-health-microbes-arent-the-enemy-theyre-a-big-part-of-who-we-are-79116">Essays on health: microbes aren't the enemy, they're a big part of who we are</a>
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<h2>What signs can parents look out for?</h2>
<p>If you think your child has outgrown their food allergy, it’s important not to test them yourself to see what happens. This is extremely unsafe and they may have a severe allergic reaction.</p>
<p>However, you may have noticed your child has accidentally eaten a food allergen but did not develop an allergic reaction. This may indicate your child has outgrown the food allergy.</p>
<p>That’s when it’s time to consult an allergy specialist – a doctor who specialises in diagnosing and managing patients with allergic diseases – to investigate.</p>
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<a href="https://images.theconversation.com/files/316526/original/file-20200220-92530-1ab8tpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316526/original/file-20200220-92530-1ab8tpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316526/original/file-20200220-92530-1ab8tpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316526/original/file-20200220-92530-1ab8tpq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316526/original/file-20200220-92530-1ab8tpq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316526/original/file-20200220-92530-1ab8tpq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316526/original/file-20200220-92530-1ab8tpq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316526/original/file-20200220-92530-1ab8tpq.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">An allergy specialist will conduct tests, including a skin prick test, to see whether your child has really outgrown a food allergy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/allergy-skin-prick-tests-175616312">Shutterstock</a></span>
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<h2>Here’s what an allergy specialist will do</h2>
<p>The allergy specialist will conduct a <a href="https://www.allergy.org.au/patients/allergy-testing/allergy-testing">number of tests</a> to monitor your child, either annually or every few years, depending on the allergen. These tests include <a href="https://dermnetnz.org/topics/skin-prick-testing/">skin prick tests</a> and blood tests.</p>
<p>These tests indicate changes in the immune system to give us an idea of whether your child has outgrown an allergy or it persists.</p>
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<strong>
Read more:
<a href="https://theconversation.com/early-exposure-to-infections-doesnt-protect-against-allergies-but-getting-into-nature-might-126603">Early exposure to infections doesn't protect against allergies, but getting into nature might</a>
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<p>When these tests indicate almost no allergic response, your child will have an <a href="https://www.allergy.org.au/patients/food-allergy/food-allergy-challenges-faqs">oral food challenge</a> under medical supervision. </p>
<p>For example, a child will be given the food allergen in increasing amounts in a medical facility. If the child tolerates the food (known as passing the challenge), the food is regularly reintroduced into the diet.</p>
<p>Food challenge tests are also done to see if a child can tolerate foods in a modified form. For example, a child allergic to eggs or cow’s milk may be able to tolerate baked egg or baked milk.</p>
<p>In general, it’s only with a medically supervised oral food challenge that allergy specialists can say whether your child has really outgrown their food allergy.</p>
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<p><em>If your child has a food allergy, more information is available from <a href="https://allergyfacts.org.au/">Allergy & Anaphylaxis Australia</a> and the <a href="https://www.allergy.org.au/patients/food-allergy">Australasian Society of Clinical Immunology and Allergy</a>. You can also listen to the <a href="https://www.podcastoneaustralia.com.au/podcasts/allergies">Allergies podcast</a>, by Murdoch Children’s Research Institute’s specialists Professors Katie Allen and Mimi Tang.</em></p><img src="https://counter.theconversation.com/content/130455/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paxton Loke 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 your child has accidentally eaten something you thought they were allergic to, but doesn’t have a response, they may have grown out of their food allergy. Here’s the safest way to check.Paxton Loke, Paediatric Allergist and Immunologist, Murdoch Children's Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1271202019-12-15T18:57:25Z2019-12-15T18:57:25ZTough nuts: why peanuts trigger such powerful allergic reactions<figure><img src="https://images.theconversation.com/files/304638/original/file-20191202-67034-15rieby.jpg?ixlib=rb-1.1.0&rect=138%2C621%2C3869%2C1478&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The humble peanut. Tasty for most, treacherous for some.</span> <span class="attribution"><span class="source">Dr Dwan Price</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Food allergens are the scourge of the modern school lunchbox. Many foods contain proteins that can set off an oversized immune reaction and one of the fiercest is the humble peanut. </p>
<p>Around <a href="https://www.sciencedirect.com/science/article/abs/pii/S0091674911001357">3% of children in Australia</a> have a peanut allergy, and only <a href="https://www.ncbi.nlm.nih.gov/pubmed/11174206">1 in 5 of them</a> can expect to outgrow it. For these unlucky people, even <a href="https://www.jacionline.org/article/S0091-6749(97)70161-1/fulltext">trace</a> amounts of peanut can trigger a fatal allergic reaction. </p>
<p>But what sets the peanut apart from other nuts? Why is it so good at being an allergen? </p>
<p>To answer this, we have to explore the pathway from allergen to allergy, and just what it is about an allergen that triggers a response from the immune system.</p>
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Read more:
<a href="https://theconversation.com/what-are-allergies-and-why-are-we-getting-more-of-them-40318">What are allergies and why are we getting more of them?</a>
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<h2>How food gets to the immune system</h2>
<p>Before coming into contact with the immune system, an allergen in food needs to overcome a series of obstacles. First it needs to pass through the food manufacturing process, and then survive the chemicals and enzymes of the human gut, as well as cross the physical barrier of the intestinal lining. </p>
<p>After achieving all of this, the allergen must still have the identifying features that trigger the immune system to respond.</p>
<p>Many food allergens successfully achieve this, some better than others. This helps us to understand why some food allergies are worse than others. </p>
<p>The most potent allergens – like peanuts – have many characteristics that successfully allow them to overcome these challenges, while other nuts display these traits to a lesser extent.</p>
<h2>Strength in numbers</h2>
<p>The first characteristic many allergenic foods have, especially peanuts, is strength in numbers. Both tree nuts and peanuts contain multiple different allergens. At <a href="http://www.allergen.org/index.php">last count</a>, cashews contain three allergens, almonds have five, walnuts and hazelnuts have 11 each and peanuts are loaded with no less than 17. </p>
<p>Each allergen has a unique shape, so the immune system recognises each one differently. The more allergens contained in a single food, the higher the potency.<br>
Additionally, many of these allergens also have numerous binding sites for both antibodies and specialised immune cells, further increasing their potency.</p>
<h2>Stronger through scorching</h2>
<p>The first hurdle for a food allergen is the food manufacturing process. Many nuts are roasted prior to consumption. For most foods, heating changes the structure of proteins in a way that destroys the parts that trigger an immune response. This makes them far less potent as allergens.</p>
<p>This is not the case for many tree nuts: allergens in almonds, cashews and hazelnuts survived roasting with no loss of potency. </p>
<p>And for the major peanut allergens, it’s even worse. Roasting actually makes them more potent. </p>
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<p>
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<strong>
Read more:
<a href="https://theconversation.com/can-i-prevent-food-allergies-in-my-kids-88873">Can I prevent food allergies in my kids?</a>
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<h2>The gauntlet of the gut</h2>
<p>From here, the allergen will have to survive destruction by both stomach acid and digestive enzymes within the human gut. Many nut allergens have the ability to evade digestion to some degree. </p>
<p>Some simply have a robust structure, but peanut allergens actively <a href="https://www.ncbi.nlm.nih.gov/pubmed?db=PubMed&cmd=Retrieve&list_uids=12847498">inhibit</a> some of the digestive enzymes of the gut. This helps them safely reach the small intestine, where the allergens then need to cross the gut lining to have contact with the immune system.</p>
<p>This is where peanut allergens really stand apart from most other allergens. They have the ability to cross the intestinal cells that make up the gut lining. Given their relative sizes, this is like a bus squeezing itself through a cat flap. </p>
<p>Peanut allergens accomplish this remarkable feat by altering the bonds that hold the gut cells <a href="https://www.karger.com/Article/FullText/362956">together</a>. They can also cross the lining by hijacking the gut’s own ability to move substances. Once across, the allergens will gain access to the immune system, and from there an allergic response is triggered.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/304604/original/file-20191202-156086-1kgvx7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/304604/original/file-20191202-156086-1kgvx7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/304604/original/file-20191202-156086-1kgvx7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/304604/original/file-20191202-156086-1kgvx7d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/304604/original/file-20191202-156086-1kgvx7d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/304604/original/file-20191202-156086-1kgvx7d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/304604/original/file-20191202-156086-1kgvx7d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/304604/original/file-20191202-156086-1kgvx7d.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">Peanut allergens attack the bonds that hold intestinal cells together.</span>
<span class="attribution"><span class="source">Dr Dwan Price</span>, <span class="license">Author provided</span></span>
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<p>The combination of multiple allergens, numerous immune binding sites, heat stability, digestion stability, enzyme blocking, and the effect on the gut lining makes peanut a truly nasty nut. </p>
<h2>Where to from here?</h2>
<p>This leaves us with a nagging question: if peanuts are so potent, why doesn’t everyone develop a peanut allergy? We still don’t know. </p>
<p>Recently, a potential <a href="https://unisa.edu.au/Media-Centre/Releases/2019/peanut-allergy-vaccine-to-rewrite-the-immune-system/">vaccine</a> developed by researchers from the University of South Australia has shown promise in reprogramming the immune system of mice and blood taken from people with peanut allergy. Will this translate to a potential treatment for peanut allergy? We will have to wait and see.</p>
<p>For now, the more we learn about the action of allergens, and the more we understand their effects on our body, the more we can develop new ways to stop them. And eventually, we might outsmart these clever nuts for good.</p><img src="https://counter.theconversation.com/content/127120/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Dwan Price was supported by an Australian Postgraduate Award from the federal government. </span></em></p>Peanut allergens have multiple allergenic traits that set them apart from other nuts.Dwan Price, Molecular Biologist and Postdoc @ Deakin AIRwatch pollen monitoring system., Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1233332019-10-01T12:28:46Z2019-10-01T12:28:46ZA father-physician tests if a little peanut a day keeps allergy away<figure><img src="https://images.theconversation.com/files/293297/original/file-20190919-22450-18ijms5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Creamy and smooth peanut butter and peanuts can trigger deadly reactions in those with allergies.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/creamy-smooth-peanut-butter-jar-on-316086323">inewsfoto/Shutterstock.com</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>No one I knew had food allergy, let alone peanut allergy, when I was a child. I grew up at a time when peanuts were given freely on airplanes, and there was no such thing as a peanut-free table at school. Fast forward to today and the world has changed, with food allergies taking on almost <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=Food+Allergy%3A+An+Enigmatic+Epidemic">epidemic-like proportions</a>. </p>
<p>I am an allergist and became interested in food allergies in 2004 after spending a month working with Dr. Wesley Burks, one of the world’s leaders in food allergy research, at the Duke Allergy Clinic. I was fascinated that a simple peanut could cause the immune system to go haywire. That knowledge inspired me to spend the next six years of medical training learning as much as I could about what triggered food allergies and how to treat them. This paid off in 2011 when I was invited to join the allergy faculty at the University of North Carolina. Just as I was getting settled into my new life as a doctor and researcher for food allergy, my world changed again. </p>
<p>On a Monday morning in September 2013, I gave my nine-month-old son Elliott peanut butter on toast for the first time, and then it happened. He had a severe allergic reaction: head-to-toe rash, vomiting and coughing. Suddenly food allergy was real to me in a way I could not have ever imagined.</p>
<p>Like many other parents, my first emotion was denial. When I finally accepted that he was now one of the estimated <a href="http://doi.org/10.1542/peds.2018-1235">1.6 million kids in the U.S. who have peanut allergy</a>, I hoped he would just outgrow it. Unfortunately, for peanut allergy, almost 80% of peanut-allergic kids <a href="http://doi.org/10.1016/j.jaci.2015.01.002">hang on to it for life</a>. So just as I had advised many families at my allergy clinic, I went to the pharmacy to get our EpiPen and reentered the world hoping to never have to use it.</p>
<p>Professionally, things have changed for me as well. I’ve spent the last 10 years trying to develop a therapy that can protect kids with food allergies from having severe allergic reactions or even dying. Finally, after years of testing in clinical trials, I’m hopeful that small drops of a peanut solution may bring us one step closer to making this a reality.</p>
<h2>Trying to find a cure</h2>
<p>Immunotherapy for peanut allergy works by exposing the child to small, increasing amounts of peanut each day to retrain the immune system and make it less reactive. There are a few types of immunotherapy that differ based on how the child is exposed. Oral immunotherapy uses lightly roasted peanut flour that must be eaten. What’s called epicutaneous immunotherapy is administered using a “<a href="https://www.mdmag.com/conference-coverage/aaaai-2019/mixed-results-peanut-allergy-immunotherapy-patch-trial">peanut patch</a>” that is absorbed through the skin. Sublingual immunotherapy uses liquid peanut drops that are absorbed through the mouth.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/293300/original/file-20190919-22429-fsm9f1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/293300/original/file-20190919-22429-fsm9f1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/293300/original/file-20190919-22429-fsm9f1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/293300/original/file-20190919-22429-fsm9f1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/293300/original/file-20190919-22429-fsm9f1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/293300/original/file-20190919-22429-fsm9f1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/293300/original/file-20190919-22429-fsm9f1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/293300/original/file-20190919-22429-fsm9f1.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">Mylan generic packaging of two EpiPen auto-injectors used for treatment of allergic reactions.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/saint-louis-united-states-october-18-739551895?src=NEntoTXnzVmnAzK0BOInaA-1-7">Amy Kerkemeyer</a></span>
</figcaption>
</figure>
<p>Over the past 10 years, multiple studies have shown that oral immunotherapy using peanut flour can work. The Aimmune Therapeutics company completed the largest peanut <a href="http://doi.org/10.1056/NEJMoa1812856">oral immunotherapy study</a> in the world. Also during the last decade, DBV Technologies developed its unique peanut patch and completed a <a href="http://doi.org/10.1001/jama.2019.1113">multinational study of hundreds of peanut-allergic kids</a>. (Disclosure: I consult for both of the companies that sponsored the studies.)</p>
<p>The Aimmune Therapeutics study of the oral treatment showed that the peanut flour protected 67% of the allergic kids from having allergic reactions after eating up to three and a half peanuts. Before starting treatment, less than one-third of a peanut would have triggered a reaction. But actually taking the peanut flour treatment required special timing and preparation that made it hard for some of the families. In addition, side effects like rash, stomach aches and vomiting prevented 12% of the kids from completing the treatment. </p>
<p>In contrast, the DBV peanut patch study showed that sticking the patch to the skin once a day was simple, with over 98% of patches successfully applied. The patch caused some redness, but only 2% of the kids had to stop the treatment early. However, only 35% of the kids seemed to benefit from the patch, and they were able to tolerate only one and a half peanuts.</p>
<h2>A new option for peanut allergy</h2>
<p>At UNC, my colleagues and I have been developing an alternative treatment called sublingual immunotherapy, or SLIT for short, using liquid peanut drops that are taken under the tongue. <a href="http://doi.org/10.1016/j.jaci.2019.07.030">In our recently published long-term study of peanut SLIT</a>, kids put two milligrams of peanut solution – about 1/150th of a peanut – under their tongue for two minutes daily. They continued this therapy for between three and five years, and afterwards almost 70% of the kids were able to safely eat two and half peanuts without suffering an allergic reaction. These drops have been tested by a <a href="http://doi.org/10.1016/j.jaci.2014.12.1917">multi-center NIH group</a> – called CoFAR – and a study directly <a href="http://doi.org/10.1016/j.jaci.2014.11.005">comparing the drops with the peanut flour</a> was done at Johns Hopkins. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/293962/original/file-20190925-51463-iuniq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/293962/original/file-20190925-51463-iuniq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/293962/original/file-20190925-51463-iuniq3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/293962/original/file-20190925-51463-iuniq3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/293962/original/file-20190925-51463-iuniq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/293962/original/file-20190925-51463-iuniq3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/293962/original/file-20190925-51463-iuniq3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Elliott embarks upon a safe and happy Halloween. He is not actually on any of the described treatments at this time.</span>
</figcaption>
</figure>
<p>This is at least 10 times the quantity it would take to trigger an allergic response to an accidental peanut. One-quarter of the kids in our trial finished the entire test, which involved consuming the equivalent of 17 peanuts, without any symptoms at all. About 5% of the more than 75,000 doses caused side effects, but most of them were just itching in the mouth that went away on its own. Thankfully, none of the kids needed epinephrine to treat any side effects. </p>
<p>Peanut allergy is not the end of the world, but it is life-changing. My son Elliott does not want to eat peanuts, but he does want to sit with his friends at lunch and eat that birthday cake at the party and go trick-or-treating with all the other kids. </p>
<p>It is exciting that after all this time, treatments are coming. Whether it’s peanut flour or the patch, or now possibly our liquid peanut SLIT drops, he may soon be able to do these things without worrying, just like all the other kids.</p>
<p>[ <em>You’re smart and curious about the world. So are The Conversation’s authors and editors.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=youresmart">You can read us daily by subscribing to our newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/123333/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Edwin Kim receives research funding from NIH, FARE, and the Wallace Foundation. He consults for Aimmune Therapeutics, DBV Technologies, Allakos, AllerGenis, Ukko and Vibrant America.</span></em></p>There’s a new therapy for treating peanut allergy that is showing promise in phase 3 trials.Edwin Kim, Assistant Professor of Medicine and Pediatrics and Director of the UNC Food Allergy Initiative, University of North Carolina at Chapel HillLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1163452019-05-05T16:59:00Z2019-05-05T16:59:00ZPeanut allergies: Research shows ‘oral immunotherapy’ is safe for preschoolers<figure><img src="https://images.theconversation.com/files/272325/original/file-20190502-103068-cd9p03.jpg?ixlib=rb-1.1.0&rect=9%2C214%2C6480%2C3648&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A study shows that oral immunotherapy is safe for preschool-aged children with peanut allergy when offered as routine treatment in a hospital or clinic.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>“We don’t have to live in fear anymore.”</p>
<p>That’s the common refrain from hundreds of parents of preschoolers with peanut allergy that my colleagues and I have successfully treated with peanut “oral immunotherapy” over the past two years.</p>
<p>Oral immunotherapy (OIT) is a treatment in which a patient consumes small amounts of an allergenic food, such as peanut, with the dose gradually increased to a target maximum (or maintenance) amount. The goal for most parents is to achieve desensitization — so their child can ingest more of the food without triggering a dangerous reaction, protecting them against accidental exposure.</p>
<p>A <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(19)30420-9/fulltext">recent study published in <em>The Lancet</em></a> has suggested that <a href="https://www.cbc.ca/news/health/peanut-allergy-immunotherapy-review-1.5111351">this treatment may make things worse</a> for children with peanut allergies. The researchers behind the meta-analysis argue that children with peanut allergies should avoid peanuts.</p>
<p>This study has limitations however. It did not include a single child under the age of five years old. And it runs the risk of confusing parents. </p>
<p>My colleagues and I have seen firsthand that oral immunotherapy is not only safe, but is well tolerated in a large group of preschool children. We published data demonstrating this recently in the <a href="https://www.jaci-inpractice.org/article/S2213-2198(19)30383-6/abstract"><em>Journal of Allergy and Clinical Immunology: In Practice</em></a>.</p>
<h2>Safe for preschoolers</h2>
<p>For any parent of a child with severe allergy, the idea of giving them even a small amount of the allergenic food might give them pause. I don’t blame them — giving a child a known allergen is a daunting thought. Some allergists share this fear and do not offer OIT to patients in their clinics due to safety concerns.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/272660/original/file-20190505-103071-5fuw15.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272660/original/file-20190505-103071-5fuw15.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272660/original/file-20190505-103071-5fuw15.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272660/original/file-20190505-103071-5fuw15.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272660/original/file-20190505-103071-5fuw15.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272660/original/file-20190505-103071-5fuw15.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272660/original/file-20190505-103071-5fuw15.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">For some children, oral immunotherapy can allow them to eat with less fear of cross-contamination.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>To assess the safety of oral immunotherapy, we followed 270 children across Canada between the ages of nine months and five years who were diagnosed with peanut allergy by an allergist. </p>
<p>The children were fed a peanut dose, in a hospital or clinic, that gradually increased at every visit. Parents also gave children the same daily dose at home, between clinic visits, until they reached the maintenance dose. </p>
<p>We found that 243 children (90 per cent) reached the maintenance stage successfully. Only 0.4 per cent of children experienced a severe allergic reaction. </p>
<p>Out of over 40,000 peanut doses, only 12 went on to receive <a href="https://medlineplus.gov/druginfo/meds/a603002.html">epinephrine</a> (0.03 per cent).</p>
<p>Our research provides the first real-world data that OIT is safe for preschool-aged children with peanut allergy when offered as routine treatment in a hospital or clinic, rather than within a clinical trial.</p>
<h2><em>The Lancet</em> study was of older children</h2>
<p>So why does the meta-analysis published in <em>The Lancet</em> show that peanut OIT increases allergic reactions, compared with avoidance or placebo? </p>
<p>The researchers behind this study argue that avoidance of peanut is best for children with peanut allergy. They describe that in older children, the risk of anaphylaxis is 22.2 per cent and the risk of serious adverse events is 11.9 per cent. </p>
<p>It is important for parents to note that <em>The Lancet</em> study only assessed children aged five and older participating in clinical trials (average age nine years old), and the researchers don’t even mention this as a limitation of their analysis. </p>
<p>Our study, on the other hand, assessed preschool children (average age just under two years old) in the real world outside of research. </p>
<p>While I agree that there are certainly more safety concerns in older children, and more research is needed to see which of them would most benefit, our results demonstrate with real-world data that, in preschoolers, OIT is a game-changer.</p>
<h2>For many patients, benefits outweigh risks</h2>
<p>It isn’t rocket science that avoiding what one is allergic to will be safer than eating it. </p>
<p>An analogy is knee replacement surgery. Of course, not having knee replacement surgery would be “safer” than having the surgery. But not having knee replacement surgery doesn’t provide any potential of benefits and also provides little hope for families. </p>
<p>Likewise, telling parents of children with peanut allergy that avoidance is the only option outside research fails to take into account the negative long-term consequences of avoidance — such as poor quality of life, social isolation and anxiety. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/272323/original/file-20190502-103057-ws4dw5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272323/original/file-20190502-103057-ws4dw5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272323/original/file-20190502-103057-ws4dw5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272323/original/file-20190502-103057-ws4dw5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272323/original/file-20190502-103057-ws4dw5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272323/original/file-20190502-103057-ws4dw5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272323/original/file-20190502-103057-ws4dw5.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">Birthday parties can be a source of anxiety for young children with peanut allergies as even peanut-free cakes, crackers and other snacks may have been produced in facilities where tree nuts are present, and could potentially be cross-contaminated.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Allergists and the medical community as a whole must stop confusing parents with endless mixed messages about OIT both within and outside of research. The fact is, many allergists are already offering OIT outside of research. In our current era of basing medical treatment decisions on a comparison of risks versus benefits, there is simply no one-size-fits-all approach. </p>
<p>Rather than concluding that all children with peanut allergy should be managed with avoidance, we should be concluding that there are some patients, such as preschoolers, for whom the benefits of offering this treatment outweigh the risks. OIT has proven to be effective in many studies, and we will similarly follow the progress of our patients long term to track effectiveness.</p>
<p>The bottom line is this: OIT is safe for preschool children and should be considered for families of those very young children with peanut allergy who ask for it.</p><img src="https://counter.theconversation.com/content/116345/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Edmond Chan receives research funding from DBV Technologies, CIHR and the BC Children's Hospital Foundation. He is affiliated with Food Allergy Canada, CSACI and NIAID. </span></em></p>Avoidance is not the only option for very young children with peanut allergies.Edmond S. Chan, Pediatric Allergist; Head & Clinical Associate Professor, Division of Allergy & Immunology, Department of Pediatrics, Faculty of Medicine; Investigator, BC Children's Hospital Research Institute, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1136252019-03-15T16:30:03Z2019-03-15T16:30:03ZFood allergies: what you need to know about the role your skin plays<figure><img src="https://images.theconversation.com/files/264150/original/file-20190315-28471-aqzaau.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/davidjlee/9336083592/">David Lee/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Food allergies are on the increase worldwide, ranging from minor inconvenience to possible sudden death, and leading to warnings of an “<a href="https://www.jaci-inpractice.org/article/S2213-2198(18)30036-9/fulltext">allergy epidemic</a>”. The most severe form of allergic reaction – <a href="https://www.aaaai.org/conditions-and-treatments/allergies/anaphylaxis">anaphylaxis</a> – can occur repeatedly or without warning. The reasons for the rise in allergies are complex, but the skin is now recognised to play an important role as a gatekeeper for the body’s immune system.</p>
<p>Human skin is a protective barrier that provides a dynamic covering, ensuring essential fluids (including water, proteins and minerals) remain inside while damaging substances remain outside. The skin barrier is structural – like a brick wall – but it is also living and active, constantly sensing and responding to the external environment. This barrier is made up of multiple layers of interconnected human cells, plus a multitude of <a href="https://www.ncbi.nlm.nih.gov/books/NBK279387/">microbes</a>, the tiny organisms that live on the surface of healthy skin.</p>
<p>Skin forms a continuous lining on the outer surface of the body which joins seamlessly with the lining of the mouth and gut. Human cells are normally introduced to foodstuffs through the mouth, but the body can also be exposed to food on the skin surface. </p>
<p>The <a href="https://www.stanfordchildrens.org/en/topic/default?id=all-about-the-immune-system-90-P01665">immune system</a> – cells and tissues that work together to defend the body against potentially harmful viruses, bacteria and foreign substances – may react very differently when food is first encountered through skin instead of through the mouth. This is because “leaky” skin may confuse the immune system’s capacity to recognise a harmless substance. </p>
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<h2>Of mice and humans</h2>
<p>Mice exposed to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3587010/">egg white</a> or <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4347216/">peanut</a> through skin have been shown to develop allergic reactions or anaphylaxis to these foods when they are then eaten. Human food allergy may develop in the same way.</p>
<p>When food is consumed we normally develop <a href="https://www.niaid.nih.gov/research/immune-tolerance">tolerance</a>, meaning no immune reaction occurs. But when skin is leaky because of <a href="https://www.nhs.uk/news/genetics-and-stem-cells/new-genetic-clue-to-peanut-allergy/">faulty genes</a> or when skin is damaged by a condition such as <a href="https://www.aaaai.org/global/latest-research-summaries/Current-JACI-Research/eczema-food-allergy">eczema</a>, food allergens may pass through. This stimulates immune cells in the skin, which release chemical signals of attack. Then the next time that specific food is encountered the cells are primed to produce an allergic reaction.</p>
<hr>
<p><em><strong>Read more: <a href="https://theconversation.com/more-people-are-experiencing-severe-food-allergies-than-ever-before-108124">More people are experiencing severe food allergies than ever before</a></strong></em> </p>
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<p>The “leakiness” of baby skin soon after birth (measured by how much water evaporates from the surface) can <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=Skin+barrier+impairment+at+birth+predicts+food+allergy+at+2+years+of+age.+Irvine">predict their risk</a> of food allergy at the age of two. And <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=The+nonlesional+skin+surface+distinguishes+atopic+dermatitis+with+food+allergy+as+a+unique+endotype">recent research</a> has shown that people with a food allergy have molecular evidence that their skin is leaky and primed to react, even if the skin looks to be normal. </p>
<h2>Treatment and prevention</h2>
<p>In an emergency situation, a food allergy is treated with drugs that counteract the <a href="https://www.nhs.uk/conditions/anaphylaxis/treatment/">most dangerous features</a> of an anaphylactic response: low blood pressure and airway obstruction. <a href="https://www.wisegeek.com/what-is-adrenaline.htm">Adrenaline</a> (administered outside of hospitals by auto-injector “pen”) causes blood vessels to squeeze tight – to maintain the blood pressure – while <a href="https://www.nhs.uk/conditions/bronchodilators/">bronchodilator drugs</a> cause the airways to open. Steroid treatment can dampen down the harmful effects of an overactive immune response. So <a href="https://www.nhsinform.scot/tests-and-treatments/medicines-and-medical-aids/types-of-medicine/corticosteroids">corticosteroids</a> are also used to limit the production of inflammatory signals in the blood and throughout the body. </p>
<p>Parents and carers often ask what they can do to help prevent the development of food allergy, especially if there is a history of allergies in the family. The Enquiring About Tolerance, or “EAT”, <a href="https://www.nejm.org/do/10.1056/NEJMdo005063/full/?requestType=popUp&relatedArticle=10.1056%2FNEJMoa1514210">study</a>, showed that introduction of peanut and egg into the diet of babies from three months of age could reduce the likelihood of developing an allergy to these foods. The protective effect was less clear with other common foods such as milk, fish, wheat and sesame. This may be because smaller amounts of these foods were consumed.</p>
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<img alt="" src="https://images.theconversation.com/files/264117/original/file-20190315-28496-hxha8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/264117/original/file-20190315-28496-hxha8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/264117/original/file-20190315-28496-hxha8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/264117/original/file-20190315-28496-hxha8b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/264117/original/file-20190315-28496-hxha8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/264117/original/file-20190315-28496-hxha8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/264117/original/file-20190315-28496-hxha8b.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">Skin conditions like eczema that break the surface of the skin are often associated with food allergies.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/580580401?size=medium_jpg&src=lb-59856941&sort=newestFirst&offset=3">Shutterstock</a></span>
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<p>Another <a href="https://trialsjournal.biomedcentral.com/articles/10.1186/s13063-017-2031-3">ongoing study</a> aims to determine whether the use of moisturisers (known as emollients) on babies can improve the skin barrier to help prevent eczema and food allergies. The results are eagerly awaited, but further research will still be needed to clarify if – and how – food allergy can be prevented.</p>
<p>In the meantime, UK government guidance continues to advise that babies should be <a href="https://www.nhs.uk/conditions/pregnancy-and-baby/benefits-breastfeeding/">exclusively breastfed</a> until six months of age. Although it is <a href="https://www.ncbi.nlm.nih.gov/pubmed/26192405">not known</a> whether breastfeeding protects against food allergy, it is clear that breast milk can provide many health benefits for the baby and mother.</p>
<p>Some people grow out of their food allergies, but for others it becomes a life-long burden of carefully avoiding the offending foodstuff. Attempts to prevent any accidental exposure may fail with disastrous consequences such as in <a href="https://www.bbc.co.uk/news/uk-45679320">the case</a> of teenager Natasha Ednan-Laperouse who had a sesame allergy and died of cardiac arrest after she ate a baguette which she did not know contained sesame seeds.</p>
<p>While accidental exposure to food can be very dangerous, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6284278/">immunotherapy</a> – the deliberate application of food substances to the surface of healthy skin – is being tested in clinical trials for the treatment of peanut and milk allergy. </p>
<p>A greater understanding of the causes of allergy will offer the opportunity to develop new treatments – and our own skin may provide a route to prevention as well as treatment for life-threatening reactions.</p><img src="https://counter.theconversation.com/content/113625/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sara J Brown receives research funding from the Wellcome Trust, the Tayside Dermatological Research Charity and the British Skin Foundation and is a medical adviser for Eczema Outreach Support.</span></em></p>With food allergies on the rise, it’s important to understand the role the skin plays in protecting or exposing us to reactions.Sara Brown, Professor of Molecular and Genetic Dermatology, Wellcome Trust Senior Research Fellow, University of DundeeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1081242018-12-05T16:44:37Z2018-12-05T16:44:37ZMore people are experiencing severe food allergies than ever before<figure><img src="https://images.theconversation.com/files/249002/original/file-20181205-186085-1s3kp54.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/peanut-butter-sandwiches-toasts-on-wooden-576773974">Shutterstock</a></span></figcaption></figure><p>The <a href="https://www.bbc.co.uk/news/uk-45679320">recent inquest</a> into the death of Natasha Ednan-Laperouse from anaphylaxis after eating a Pret A Manger baguette she was unaware contained sesame, could lead to a change in <a href="https://www.theguardian.com/society/2018/oct/23/pret-allergy-death-parents-to-meet-gove-over-food-labelling">labelling legislation</a>. Indeed, a <a href="https://www.bbc.co.uk/news/uk-england-46345097">recent investigation</a> found that undeclared allergens were present in a quarter of foods sampled. But a more fundamental issue needs to be addressed: why are more people experiencing severe food allergies than ever before?</p>
<p>As I explain in <a href="https://cup.columbia.edu/book/another-persons-poison/9780231164856">Another Person’s Poison: A History of Food Allergy</a>, strange reactions to food have long been known. The Ancient Greek physician <a href="https://www.britannica.com/biography/Hippocrates">Hippocrates</a> (c.460-370BC) described such reactions to various foods, including cheese. Strawberries caused Richard III to break out into hives. It is said he once sneakily consumed “a messe of strauberies”, and then blamed his reaction on witchcraft orchestrated by one of his opponents, who was summarily beheaded. By the time Austrian physician <a href="https://www.ncbi.nlm.nih.gov/pubmed/27794078">Clemens von Pirquet</a> coined <a href="https://www.ncbi.nlm.nih.gov/pubmed/17136331">the term</a> “allergy” in 1906, many believed that food could trigger skin problems, asthma, gastrointestinal distress and even mental disorders.</p>
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<p>In the 1930s, food allergy emerged as a distinctive sub-category of allergy. But it was also highly controversial. Although it was easy to identify the food at fault in anaphylactic reactions, such as the one that killed Ednan-Laperouse, these sudden reactions were rare. Food allergists tended to focus instead on patients whose reactions were delayed, occurring up to 48 hours after eating the suspected food and, so, much more difficult to diagnose. These reactions were typified by symptoms such as eczema, diarrhoea, asthma, migraine and psychiatric problems, including depression and hyperactivity.</p>
<p>Many doctors, however, doubted the claims of food allergists that food allergy was responsible for much undiagnosed chronic illness. In fact, some were so unconvinced that they would refer patients complaining of chronic food allergy to psychiatrists, believing that their symptoms were <a href="https://www.psychologytoday.com/gb/blog/happiness-in-world/201003/psychosomatic-symptoms">psychosomatic</a>. The heated debates that would emerge during the post-war period about the prevalence of food allergy distracted researchers from investigating the root causes of the condition.</p>
<h2>Enter the peanut</h2>
<p>In the early 1980s, food allergy became a marginalised topic within medicine. Then, a new phenomenon emerged that forced doctors to take it seriously: <a href="https://www.allergyuk.org/information-and-advice/conditions-and-symptoms/36-types-of-food-allergy?gclid=EAIaIQobChMIq-SThsiG3wIVlOJ3Ch1TQQEsEAAYASAAEgI-sfD_BwE#download_access">peanut allergy</a>. In 1988, an article in the Canadian Medical Association Journal described the case of a 24-year-old woman who died after eating a biscuit that contained peanut oil. Although one or two similar stories had been reported previously in newspapers, this was the first report made in a medical journal. It would not be the last.</p>
<p>By the 1990s, peanut allergy fatalities were commonplace. According to US charity <a href="https://www.charities.org/charities/food-allergy-research-education-inc-fare">Food Allergy Research and Education</a> (FARE), rates of peanut and tree nut allergy <a href="https://www.foodallergy.org/life-with-food-allergies/food-allergy-101/facts-and-statistics">tripled</a> between 1997 and 2008 among American children. As a result, food allergy became associated with these severe, potentially fatal, allergies, rather than the chronic food allergies on which food allergists had previously concentrated.</p>
<p>FARE and other allergy charities successfully lobbied for better labelling, more peanut-free spaces (in schools for instance) and the availability of life-saving <a href="https://obamawhitehouse.archives.gov/blog/2013/11/13/president-obama-signs-new-epipen-law-protect-children-asthma-and-severe-allergies-an">epipens</a> which administer a dose of epinephrine (a chemical that narrows blood vessels and opens airways in the lungs) to anyone suffering an anaphylactic reaction.</p>
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<img alt="" src="https://images.theconversation.com/files/249003/original/file-20181205-186085-fj8fl3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249003/original/file-20181205-186085-fj8fl3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249003/original/file-20181205-186085-fj8fl3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249003/original/file-20181205-186085-fj8fl3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249003/original/file-20181205-186085-fj8fl3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249003/original/file-20181205-186085-fj8fl3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249003/original/file-20181205-186085-fj8fl3.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 increasing use of soy, which is related to the peanut, is said to contribute to allergy problems.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/tractor-spraying-soybean-crops-pesticides-herbicides-289460621">Shutterstock</a></span>
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<p>But they failed to convince scientists to conduct detailed investigations into why such allergies were increasing so rapidly. On the one hand, this reluctance was understandable. There was a pressing need to provide new treatments and support to the increasing number of people suffering from severe food allergies. On the other, scientists were hesitant to investigate a condition that had long been considered a <a href="https://www.bmj.com/content/337/bmj.a2880">fad</a> – a suspicious and divisive diagnosis that was too reliant on patient accounts for its justification.</p>
<p>While research continues to explore <a href="https://www.nhs.uk/news/medical-practice/peanut-allergy-therapy-shows-promise/">potential cures</a> and treatments, not enough effort has been spent on exploring root causes. Into the vacuum has emerged a number of controversial explanations, many of which have not been based on much scientific research.</p>
<h2>Possible explanations</h2>
<p>One suggestion is the <a href="http://www.bbc.com/future/story/20151118-can-you-be-too-clean">hygiene hypothesis</a>, which argues that children grow up in excessively clean environments, meaning that their bodies struggle to distinguish between harmful pathogens and harmless proteins, such as those found in peanuts. <a href="https://www.ncbi.nlm.nih.gov/pubmed/11398088">Others point to cooking techniques</a>, indicating that peanut allergy is more common in countries where peanuts are roasted, rather than boiled.</p>
<hr>
<p><em><strong>Read more: <a href="https://theconversation.com/what-are-allergies-and-why-are-we-getting-more-of-them-40318">What are allergies and why are we getting more of them?</a></strong></em> </p>
<hr>
<p><a href="https://www.nhs.uk/news/pregnancy-and-child/some-babies-should-be-given-peanuts-early-say-new-us-guidelines/">Infant feeding is also implicated</a>, the most recent advice being that mothers with a family history of allergy should introduce peanuts early on. <a href="https://www.ncbi.nlm.nih.gov/pubmed/12637607">Increased use of soya</a> (a relative of the peanut) in food production has also been suggested. But none of these explanations have proved completely convincing, leading to the emergence of <a href="https://www.skyhorsepublishing.com/9781510726314/the-peanut-allergy-epidemic-third-edition/">even more controversial</a> hypotheses.</p>
<p>The truth is that we simply don’t yet know what is triggering the peanut allergy epidemic or increasing rates of food allergy. A chief reason for this is a lack of open-minded research into the causes of allergy. The explanations that emerge from such research might not be easy for people to accept if they indicate that food allergy is a byproduct of modern lifestyles, new diets or changes in how people interact with their environment. Investigating the causes of food allergy will not be easy, but if medicine is to prevent more tragedies such as the teenager Ednan-Laperouse, it will be essential.</p><img src="https://counter.theconversation.com/content/108124/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Smith received funding from the Wellcome Trust for this project. </span></em></p>A worrying lack of open-minded research means we do not know exactly why food allergy is on the rise.Matthew Smith, Professor in Health History, University of Strathclyde Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1048812018-10-16T15:06:20Z2018-10-16T15:06:20ZCurious Kids: if you have lots of the thing you’re allergic to, does your body get used to it?<figure><img src="https://images.theconversation.com/files/240814/original/file-20181016-165918-1fshi24.jpg?ixlib=rb-1.1.0&rect=95%2C27%2C4432%2C2966&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/little-asian-boy-has-allergies-flower-397846021?src=1EuFgJwIEmV76yzFhQ55Bg-1-8">Shutterstock.</a></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a series for children of all ages. The Conversation is asking young people to send in questions they’d like an expert to answer. All questions are welcome: find out how to enter at the bottom.</em> </p>
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<blockquote>
<p><strong>If you have lots of the thing you’re allergic to, does your body eventually get used to it? – Karen and Dawn, age 14 and nine, Manchester, UK</strong></p>
</blockquote>
<p>Thanks for your brilliant question, Karen and Dawn! As usual with science, there is not a simple answer. But the first thing to say is that if you know you are allergic to something, you must not purposefully go near it or eat it to try and make your allergy better. It won’t work and might make you very unwell. </p>
<p>Some people are allergic to things in the air, such as pollen, dust and animal hair. Other people are allergic to certain foods, or things that we touch. </p>
<p>When you are allergic to something, your body mistakenly thinks that the thing you are allergic to is going to cause you harm. </p>
<p>This triggers your immune system (which normally fights infections) to start fighting whatever you’re allergic to. Then you get symptoms, which are the signs that something is wrong in your body. </p>
<p><a href="https://www.nhs.uk/conditions/allergies/symptoms/">The symptoms</a> could be anything from an itchy nose and sneezing to breathing problems or a skin rash. In the case of serious allergies, people may get a swollen tongue or throat, which can be very dangerous. </p>
<p>There are some very serious allergies that you must always be very careful with, because they can lead to a very serious medical problem called anaphylaxis. </p>
<p>The most common foods that cause anaphylaxis are nuts and eggs. People who have these allergies must carry a special injection with them all the time, in case they accidentally eat these things, and they always need to be extra careful around food. </p>
<p>Some less serious allergies, such as hay fever, might get better if you were stuck on an island for a long period of time with no medication. This is because our bodies can get used to the pollen that causes this allergy. </p>
<p>There are <a href="https://www.nhs.uk/conditions/allergies/treatment/">medical ways</a> of testing this, which experts call “desensitisation therapy” or “immunotherapy”. This means that you are given a certain amount of the thing you are allergic to every day, until you become less sensitive to it. This should always be done with the help of a doctor, and it doesn’t work for all allergies. </p>
<p>There are some things that you might be intolerant to, but not allergic to. This means that when you eat it, you might get some tummy trouble, but it would not cause you any serious harm.</p>
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<img alt="" src="https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=383&fit=crop&dpr=1 600w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=383&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=383&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=481&fit=crop&dpr=1 754w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=481&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/240816/original/file-20181016-165909-1je462h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=481&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">Milk can give some people a sore tummy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/cute-little-girl-drinking-milk-countryside-674878165?src=rSXm8E-p4NcNjfGpNy3D3g-1-4">Shutterstock.</a></span>
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<p>Milk is a really good example of this. There is a type of sugar in milk called lactose. To digest lactose, humans need a special chemical called an enzyme, which is made in our intestines. </p>
<p>When we are babies, we all produce lots of this enzyme because we only have milk. Some people stop making the enzyme altogether when they are adults and some people might just make a bit less of it. And some people will produce more or less of it depending on how much milk they drink. </p>
<p>That means that sometimes, if you haven’t had much milk for a while, then you have a lot, you might have a sore tummy. But you might also find that the more milk you have, the more of the enzyme your gut produces and the more milk you can enjoy without a tummy ache. </p>
<p>Only milk from animals (including humans) has the sugar lactose in it, anything that is made from plants like coconut milk, soya milk and almond milk does not contain any lactose. </p>
<p>But whether you’ve got an allergy or an intolerance, it’s very important to always follow your doctor’s instructions.</p>
<hr>
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<img alt="" src="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p><em>Please tell us your name, age and which town or city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question, but we will do our best.</em></p>
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<p><em>More <a href="https://theconversation.com/topics/curious-kids-36782?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Curious Kids</a> articles, written by academic experts:</em></p>
<ul>
<li><p><em><a href="https://theconversation.com/curious-kids-why-do-hens-still-lay-eggs-when-they-dont-have-a-mate-104077?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Why do hens still lay eggs when they don’t have a mate? – Finley, age ten; Evie, age eight; and Jonah, age five, Cambridgeshire, UK</a></em></p></li>
<li><p><em><a href="https://theconversation.com/curious-kids-whats-the-history-of-aircraft-squawk-codes-and-how-do-they-work-103102?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">What’s the history of aircraft squawk codes and how do they work? – Daniel, age 12, Perth, Australia</a></em></p></li>
<li><p><em><a href="https://theconversation.com/curious-kids-how-can-chickens-run-around-after-their-heads-have-been-chopped-off-103701?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">How can chickens run around after their heads have been chopped off? – Gaelle, age four, Bristol, UK</a></em></p></li>
</ul><img src="https://counter.theconversation.com/content/104881/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sophie Medlin 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>Don’t try this at home, kids.Sophie Medlin, Lecturer in Nutrition and Dietetics, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/888732018-01-09T19:36:04Z2018-01-09T19:36:04ZCan I prevent food allergies in my kids?<figure><img src="https://images.theconversation.com/files/199171/original/file-20171214-27555-jq68k5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There's still a lot we don't know about why more children have food allergies today. </span> <span class="attribution"><span class="source">from www.shutterstock.com</span></span></figcaption></figure><p>With the rise in food allergies over the last ten to 20 years, parents are understandably concerned about what – if anything – can be done to reduce the chances of their child developing a food allergy. Expectant mums often ask whether there’s anything they should eat, or avoid eating, to reduce the risk of food allergy in their child. </p>
<p>In the past, some guidelines recommended mums avoid eating “allergenic” foods (foods that commonly cause reactions in individuals with food allergy) during pregnancy and breastfeeding. This advice has now been removed because it hasn’t prevented food allergies in the child. So what do we know (and not know) about the link between foods eaten during pregnancy and food allergies in children?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-do-we-get-allergic-to-food-82503">Curious Kids: How do we get allergic to food?</a>
</strong>
</em>
</p>
<hr>
<h2>What is a food allergy?</h2>
<p>There are many different types of reactions to foods. Those involving the immune system are classified as allergies. </p>
<p>The type of allergy most studied is called “IgE-mediated” food allergy (IgE refers to immunoglobulin - the antibodies produced by our immune system). In IgE-mediated food allergy, the immune system responds to a particular food or foods in the same way it would respond to something dangerous. It causes symptoms that we call an allergic reaction. Food allergy can occur to a wide range of foods, but common culprits are peanut, tree nuts, egg, milk, soy, wheat, fish and shellfish. </p>
<p>For people with this type of food allergy, reactions generally occur rapidly, sometimes within minutes of ingesting the food. Common symptoms include hives (raised wheals that resemble mosquito bites), vomiting, and swelling of the lips, eyes, or face. Less commonly, reactions can involve the airways or circulation, resulting in potentially life-threatening symptoms like difficulty breathing, wheezing or collapse.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/199173/original/file-20171214-27597-1qua1fh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/199173/original/file-20171214-27597-1qua1fh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/199173/original/file-20171214-27597-1qua1fh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/199173/original/file-20171214-27597-1qua1fh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/199173/original/file-20171214-27597-1qua1fh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/199173/original/file-20171214-27597-1qua1fh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/199173/original/file-20171214-27597-1qua1fh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/199173/original/file-20171214-27597-1qua1fh.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"></a>
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<span class="caption">Peanuts should be introduced before one year of age.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
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<p>In Australia, IgE-mediated food allergy now affects around <a href="http://www.jacionline.org/article/S0091-6749(11)00135-7/abstract">one in every ten babies</a>, and around <a href="http://www.jacionline.org/article/S0091-6749(17)31017-5/abstract">one in 20 older children</a>. It usually develops in infancy or early childhood, and can be lifelong. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/food-allergies-linked-to-overactive-immune-system-at-birth-53100">Food allergies linked to overactive immune system at birth</a>
</strong>
</em>
</p>
<hr>
<h2>Can we prevent children from developing food allergy?</h2>
<p>The normal response to eating a food is “tolerance”. In other words, the immune system sees the food as harmless and does not mount a response. Interventions to prevent food allergy aim to promote the development of tolerance.</p>
<p>Ten years ago, no one knew how this could be achieved. Since then, there have been major advances. Perhaps the most important is the recent discovery by researchers in the UK that peanut allergy can be prevented in some children who are at high risk of developing it. </p>
<p>In a <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1414850#t=article">study</a> in which 600 children with eczema or egg allergy were randomly assigned to either eat or avoid peanut, those who started eating peanut earlier (before they were one year old) were less likely to have peanut allergy at age five than those who avoided peanut. Studies have also shown eating egg earlier may protect against egg allergy, although this protective effect does not appear to be as strong as for peanuts. </p>
<p>As a result of this study, <a href="https://theconversation.com/introduce-eggs-and-peanuts-early-in-infants-diets-to-reduce-the-risk-of-allergies-65564">parents are now advised</a> to introduce foods like peanut and egg to infants before one year of age.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/introduce-eggs-and-peanuts-early-in-infants-diets-to-reduce-the-risk-of-allergies-65564">Introduce eggs and peanuts early in infants' diets to reduce the risk of allergies</a>
</strong>
</em>
</p>
<hr>
<p>Although this is an important advance in knowledge, the research also showed this isn’t effective for everyone. Some children develop food allergy very early in life, too early to benefit from being given foods like peanut before one year. </p>
<p>It’s also clear infant diet isn’t the only factor that determines whether a child develops a food allergy, since most children do not develop food allergy regardless of the age when foods like peanut and egg are first given. And some children develop food allergy even with an optimal diet. </p>
<h2>Maternal diet and food allergy</h2>
<p>Immune responses to foods like egg and peanut can be detected in some infants in the first few months of life, before these foods are introduced into the infant diet. This means food allergy prevention might need to start earlier than previously thought. </p>
<p>A <a href="https://cosmosmagazine.com/biology/peanut-antigens-in-breast-milk-may-protect-kids-from-allergy">recent study in mice</a> reported that milk from mothers exposed to egg protein protected offspring from developing allergic reactions to egg. This protection was strongest when the mothers were exposed to egg proteins during both pregnancy and breastfeeding. At the moment it’s not known whether this is also the case in people.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-are-allergies-and-why-are-we-getting-more-of-them-40318">What are allergies and why are we getting more of them?</a>
</strong>
</em>
</p>
<hr>
<p>The Australasian Society of Clinical Immunology and Allergy <a href="https://www.allergy.org.au/patients/allergy-prevention/ascia-guidelines-for-infant-feeding-and-allergy-prevention">does not recommend excluding</a> allergenic foods during pregnancy or breastfeeding.</p>
<p>We don’t know yet whether eating more of foods like peanuts or eggs in pregnancy can reduce the risk of the child developing a food allergy. But answers should be available soon. A <a href="https://www.nhmrc.gov.au/media/releases/2017/33-million-wa-researchers-promises-healthier-future">study led by researchers</a> at the University of Western Australia is about to look in detail at how the amount of egg and peanut eaten by mums relates to their child’s risk of having an egg or peanut allergy.</p>
<p>This is a large study which will take several years to complete, but hopefully we will be able to provide evidence-based advice for maternal diet, the same way we can for infant diet, very soon.</p><img src="https://counter.theconversation.com/content/88873/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jennifer Koplin receives funding from the National Health and Medical Research Council of Australia. </span></em></p>Parents are now advised to introduce foods like peanut and egg to infants before one year of age.Jennifer Koplin, Research Fellow, Population Health, Murdoch Children's Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/655642016-09-20T19:54:52Z2016-09-20T19:54:52ZIntroduce eggs and peanuts early in infants’ diets to reduce the risk of allergies<figure><img src="https://images.theconversation.com/files/138377/original/image-20160920-18705-1u180h0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Up to one in ten infants have a proven food allergy.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-78217849/stock-photo-six-month-old-south-east-asian-chinese-baby-girl-sitting-in-a-yellow-seat-being-spoon-fed.html?src=pp-same_model-78217861-7&ws=1">Andy Lim/Shutterstock</a></span></figcaption></figure><p>In the 1970s, when we were in school, food allergies were rare. But Australian children now have the highest rate of food allergy in the world. Up to <a href="http://www.jacionline.org/article/S0091-6749(16)00381-X/abstract">one in ten infants</a> and two in ten school-aged children have a proven food allergy. </p>
<p>In the 14 years to 2012, there was a <a href="http://www.jacionline.org/article/S0091-6749(15)00702-2/abstract">50% increase in hospital visits</a> for anaphylaxis, the most severe allergic reaction. Infants and toddlers accounted for much of this increase. </p>
<p>The most common food allergies are to nine main food proteins: cow’s milk, soy, egg, wheat, peanut, tree nuts, sesame, fish and seafood. Egg and peanut allergies are the most common in infants and toddlers. </p>
<p>New research <a href="http://jama.jamanetwork.com/article.aspx?doi=10.1001/jama.2016.12623">published today in the Journal of the American Medical Association</a> (JAMA) shows the early introduction of egg (from four to six months) and peanuts (from four to 11 months) is linked to lower rates of egg and peanut allergy. </p>
<p>The researchers analysed the combined results of trials investigating whether food allergens in babies’ diets prevent the development of allergies to these foods. They concluded there was “moderate” certainty that early introduction of egg or peanut was associated with lower risks of egg and peanut allergy. </p>
<p>They also found that early introduction of gluten (wheat) was not associated with an increased risk of coeliac disease. </p>
<hr>
<blockquote>
<p><strong>Further reading:</strong> <a href="https://theconversation.com/everything-you-need-to-know-about-coeliac-disease-and-whether-you-really-have-it-4928">Everything you need to know about coeliac disease (and whether you really have it)</a></p>
</blockquote>
<hr>
<p>The researchers used the term “moderate certainty” because the review is based on a mix of studies with different designs and of varying quality. Feeding studies can also be difficult to “<a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2947122/">blind</a>”; for some studies participants and researchers knew who was given egg or peanut, so were open to some bias.</p>
<p>As a result, the authors say more work needs to be done to better understand the precise optimal timing for introducing eggs and peanuts. </p>
<p>Nonetheless, these findings affirm the recently updated Australian infant feeding <a href="http://www.allergy.org.au/images/pcc/ASCIA_guidelines_infant_feeding_and_allergy_prevention.pdf">consensus guidelines</a>. These state that when parents introduce solids – at around six months but not before four months – they should also introduce previously avoided foods such as peanut and egg. This should occur in the baby’s first year of life.</p>
<p>The problem is, there have been so many changes to guidelines over the last few decades that parents are no longer sure what to believe. </p>
<p>In Australia, dietary recommendations aiming to reduce the risk of food allergies began to appear in the early 1990s. They recommended infants avoid certain foods such as egg and peanut. These guidelines were largely based on outcomes of trials focusing on the mother avoiding allergens during pregnancy and while breastfeeding. </p>
<p>In 2008, a number of research projects (including <a href="http://www.ncbi.nlm.nih.gov/pubmed/20920771">our own</a>) questioned whether these older studies were flawed because they had not adequately adjusted the results to account for the fact that those with a family history of allergies adhere to recommendations better than those without, thus biasing the result. </p>
<p>These new studies accounted for this fact. We found, paradoxically, that earlier introduction of foods such as egg and peanut, at around six months, appeared to protect against food allergy. This has resulted in a complete rethink in our approach to preventing food allergy. </p>
<p>(Note that these findings relate to the prevention of food allergies, not the management, which remains unchanged. Children with food allergies should continue to avoid those foods.) </p>
<p>Based on this research, feeding guidelines began stating that earlier introduction did not increase the risk of food allergy and may indeed be protective. </p>
<p>These recommendations were strengthened this year after <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1414850#t=article">research trials tested the effect</a> of eating common allergens (in particular, peanut) in the first year of life compared with completely avoiding them. The <a href="http://www.allergy.org.au/images/pcc/ASCIA_guidelines_infant_feeding_and_allergy_prevention.pdf">guidelines now recommend</a> that exposure to egg, peanut and other foods frequently associated with food allergy should occur in the first year of life to offer protection. </p>
<p>It’s still not clear if this approach alone will prevent the whole food allergy epidemic. Some children will still develop food allergies despite following the feeding guidelines. </p>
<p>We know the tendency to develop allergic disease is inherited, but environmental factors, including the microbiome, vitamin D levels, migration effects, the number of siblings and exposure to pets also all appear to play influential roles, as does the presence of early onset eczema. Research trials are investigating the role these factors play in the development of food allergy risk.</p>
<p>In the meantime, experts agree there appears to be a window of opportunity in the first year of life where exposure to foods such as peanut and egg decreases the risk of allergy to these foods. Diet diversity remains an important part of a healthy diet. </p>
<p><em>For the most recent infant feeding guidelines and information about introducing solid foods to infants, visit <a href="http://www.allergy.org.au/patients/allergy-prevention">the Australasian Society of Clinical Immunology and Allergy</a> website.</em></p><img src="https://counter.theconversation.com/content/65564/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>New research published today shows the early introduction of egg (from four to six months) and peanuts (from four to 11 months) is linked to lower rates of egg and peanut allergy.Merryn Netting, Postdoctoral Research Fellow, Healthy Mothers, Babies and Children's Theme; South Australian Health and Medical Research Institute; Affiliate Lecturer, The University of Adelaide, University of AdelaideKatie Allen, Paediatric Gastroenterologist and Allergist, Murdoch Children's Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/403182015-10-07T19:24:44Z2015-10-07T19:24:44ZWhat are allergies and why are we getting more of them?<figure><img src="https://images.theconversation.com/files/95161/original/image-20150917-7521-3ppdou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Allergies are becoming more frequent in the western world. </span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/al-stan/3475946574/">Al Fed/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Allergies are reactions caused by the immune system as it responds to environmental substances that are usually harmless to most people. They may occur in response to a range of different material (called allergens), such as food, pollen, dust mites, animals, insect stings, or medicines.</p>
<p>An allergy can <a href="http://www.allergy.org.au">affect different parts of the body</a>. Allergic rhinitis, or hay fever, for instance, affects the nose and eyes, while eczema affects the skin. Food allergies affect the gut, skin, airways, lungs, and sometimes the entire body through the blood vessels. </p>
<p>Other conditions such as asthma, which affects the lungs, and eosinophilic oesophagitis, which affects the tube from the throat to the stomach, are closely related to allergy. But they have slightly different underlying causes. </p>
<h2>A range of reactions</h2>
<p>While most reactions are only mild to moderate in severity (and can be treated with antihistamines), some can be life-threatening and require emergency medical treatment. The most severe, systemic allergic reactions are known as anaphylaxis. People with known severe allergies should have an <a href="http://www.allergy.org.au">emergency management plan</a> that includes an adrenaline auto-injector for emergency use. </p>
<p>We can confirm whether someone has an allergy by doing a skin-prick testing or a blood test that checks whether their immune system has produced antibodies to an allergen. If the immune system has developed antibodies, it will remember the allergen as a potential threat and is likely to mount a strong immune response on subsequent exposure. </p>
<p>The likelihood of someone having an allergic reaction from future exposures to the allergen is determined by taking their clinical history and these test results into account. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/95141/original/image-20150917-12695-2a4xns.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/95141/original/image-20150917-12695-2a4xns.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=265&fit=crop&dpr=1 600w, https://images.theconversation.com/files/95141/original/image-20150917-12695-2a4xns.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=265&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/95141/original/image-20150917-12695-2a4xns.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=265&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/95141/original/image-20150917-12695-2a4xns.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=333&fit=crop&dpr=1 754w, https://images.theconversation.com/files/95141/original/image-20150917-12695-2a4xns.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=333&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/95141/original/image-20150917-12695-2a4xns.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=333&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">Allergic rhinitis, or hay fever, affects the nose and eyes.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/14353437@N06/4515249683/">parrchristy/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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</figure>
<p>In the case of food allergy, if the probability of an allergic reaction is low, people are given a food challenge. This is when increasing amounts of the offending food are administered while the person is closely observed for any signs of an allergic reaction. Of course, it can result in a reaction.</p>
<p>Allergies are becoming more frequent in Australia and the rest of the western world. <a href="http://www.allergy.org.au/">One in three people in Australia</a> will develop allergies at some time in their life. One in 20 will develop a food allergy and one in 100 will have a life-threatening allergic reaction known as anaphylaxis .</p>
<p>Hospital admissions for anaphylaxis <a href="http://www.ncbi.nlm.nih.gov/pubmed/26187235">doubled in the ten years</a> from 1994 to 2004, and were five times higher in children under five years old over the same period. This suggests the development of allergy in early life is increasing at a faster rate than in adults.</p>
<p>Children are <a href="http://www.abc.net.au/news/2015-07-15/number-of-children-hospitalised-with-food-allergies-on-the-rise/6619752">more likely to develop allergies</a> to eggs, dairy products or peanuts, while adults are more likely to develop an allergy to seafood. </p>
<h2>Possible reasons why</h2>
<p>The reasons for the rising number of allergies are not fully understood, but here are six theories.</p>
<p>1) Decreased exposure to infections or microbes – or both – in early life could lead to an increased risk of allergy. This is commonly referred to as the hygiene hypothesis, <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1838109/">first suggested in 1989</a>. <a href="http://www.ncbi.nlm.nih.gov/pubmed/21060319">Research showing</a> children who have close contact with pets or livestock and those who come from larger families are less likely to develop allergies have indirectly supported the hygiene hypothesis.</p>
<p>2) Delayed introduction of allergenic foods, such as eggs and nuts, until later in childhood could also have an impact. This is one of the most recent theories resulting from the <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1414850">LEAP study</a>, published in 2015. This randomised trial for early life peanut consumption in a population at increased risk of developing peanut allergies demonstrated that exposure to the nut early in life is protective against developing the allergy.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/95162/original/image-20150917-7517-3j4zx9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/95162/original/image-20150917-7517-3j4zx9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=385&fit=crop&dpr=1 600w, https://images.theconversation.com/files/95162/original/image-20150917-7517-3j4zx9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=385&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/95162/original/image-20150917-7517-3j4zx9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=385&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/95162/original/image-20150917-7517-3j4zx9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=483&fit=crop&dpr=1 754w, https://images.theconversation.com/files/95162/original/image-20150917-7517-3j4zx9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=483&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/95162/original/image-20150917-7517-3j4zx9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=483&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A child with a nut allergy only has a 20% chance of the allergy resolving by the time she reaches adulthood.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/aoifemac/8424630783/">Aoife Mac/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>3) Different methods of preparing foods can <a href="http://www.ncbi.nlm.nih.gov/pubmed/19000582">impact the degree</a> to which they invoke an allergic response; roasting peanuts, for instance, greatly increases allergenicity while boiling reduces it. This may in part explain difference in incidence of in peanut allergy between certain countries.</p>
<p>4) Vitamin D deficiency may increase the risk to develop allergies. Several studies show that the further away you live from the equator (hence your lower level of sunlight exposure, which is needed to make Vitamin D) – or <a href="http://www.abc.net.au/health/features/stories/2013/03/07/3710140.htm">low vitamin D blood levels increase your risk</a> of developing allergies. But the value of vitamin D treatment for preventing allergies has yet to be demonstrated. </p>
<p>5) Allergies may develop after exposure to allergens, such as dairy products or nut oils in skin moisturisers, particularly on inflamed sites, such as eczema.</p>
<p>6) Altered gut bacterial species due to low-fibre diets and widespread antibiotic usage may alter the body’s immune function and create an allergy.</p>
<p>Whether your allergy improves over time often depends on the type of allergy you have. A child with eczema, for instance, will often find her eczema improves by the time she’s a teenager. But some people will have eczema even into their adult years. In contrast, a child with peanut allergy only has a 20% chance of the allergy resolving by the time she reaches adulthood.</p>
<p>While we have treatments for the symptoms of allergy, we do not yet have a cure or the ability to prevent them from developing in the first place. We also don’t have a good test for predicting food allergy, unless we feed the person the suspected food allergen. For now, the best you can do is to manage your allergy.</p><img src="https://counter.theconversation.com/content/40318/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Collison receives funding from the NHMRC, Hunter Children's Research Foundation and the Thrasher Research Fund. He is an inventor on a provisional patent that describes a marker for peanut allergy.</span></em></p><p class="fine-print"><em><span>Joerg Mattes receives/received funding from the National Health&Medical Research Council, the Hunter Medical Research Institute, the Hunter Children's Research Foundation, Asthma Australia, Rebecca L. Cooper Medical Research Foundation. He is a listed inventor on a patent describing a peanut anaphylaxis blood biomarker.</span></em></p><p class="fine-print"><em><span>Rani Bhatia receives funding from the Hunter Children's Research Foundation. She is an inventor on a provisional patent that describes a marker for peanut allergy.</span></em></p><p class="fine-print"><em><span>Elizabeth Percival 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>Allergies are reactions caused by the immune system as it responds to environmental substances that are usually harmless. But we don’t yet have a cure or the ability to prevent them from developing.Adam Collison, Post Doctoral researcher - Experimental and Translational Respiratory Medicine Research Group, University of NewcastleElizabeth Percival, Staff Specialist General Paediatrician at John Hunter Children's Hospital, Newcastle, Australia. Conjoint Lecturer & PhD student, University of NewcastleJoerg Mattes, Professor&Chair of Paediatrics | HMRI, University of Newcastle, Australia | Senior Staff Specialist Paediatric Respiratory&Sleep Medicine | John Hunter Children's Hospital, Australia, University of NewcastleRani Bhatia, Senior Staff Specialist in Paediatric Allergy and Immunology at John Hunter Children's Hospital Newcastle NSW Conjoint Lecturer in Paediatrics, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/446872015-09-03T11:10:51Z2015-09-03T11:10:51ZThe myth of flying peanuts: not so deadly after all<figure><img src="https://images.theconversation.com/files/88396/original/image-20150714-21701-ne8kg9.jpg?ixlib=rb-1.1.0&rect=0%2C18%2C640%2C442&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Not quite true.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/dan4th/152277217/in/photolist-oUiVHa-essHg-7E3P3R-BpLUw-rhyZBJ-5Aj5cg-rhxX59-7XMSp1-b9JCAV-rfn1h4-qBTZqa-nsGi86-qMWzC5-ryx7Zi-nsGgmR-ryCYMP-qBCwgS-qi8jRn-rfn1oB-rh6ZgW-hYKrP-4LgLar-rD5Vks-5nKBGh-6HscPi-rhegD2-qBTZqF-rhegon-rgWreN-rh7Uf3-rh7U41-rh7Ueb-rhegin-qFZdfA-qGccCD-rDzczr-rJWpZi-86Lo8C-9irg4K-53QeKa-5dFTRM-8MRcJE-agynwZ-agynvi-9Zk4Kh">Dan4th Nicholas</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>By the time the Ryanair flight had touched down, four-year-old Fae Platten had been taken away by paramedics and a group of passengers were converging menacingly on a Zimbabwean man they accused of trying to kill her. His crime? He had ignored requests by the air stewardess to refrain from eating nuts on the flight and had opened a packet while sitting four rows behind the girl. The major allergic reaction it triggered <a href="http://www.telegraph.co.uk/travel/travelnews/11036175/Ryanair-bans-passenger-after-girl-suffers-nut-allergy-reaction.html">nearly killed her</a>. </p>
<p>Fae stopped breathing and was only saved by an EpiPen injection administered by the flight crew. The family knew their daughter had multiple allergies and was extremely sensitive to nuts, so passengers were told three times not to eat nuts on the three-and-a-half-hour plane journey.</p>
<h2>The airborne myth</h2>
<p>These stories of severe allergies are becoming increasingly common. Food allergy rates in kids <a href="https://www.allergyuk.org/why-is-allergy-increasing/why-is-allergy-increasing">have risen significantly</a>, affecting <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3879010/#B3">up to 10%</a> of Western kids. Researchers have suggested that in the past decade cases of peanut allergies <a href="http://www.ncbi.nlm.nih.gov/pubmed/25705822">have doubled</a> or <a href="http://www.livescience.com/8268-peanut-allergy-cases-triple-10-years.html">even tripled</a>, according to one US survey, and are becoming apparent in Africa and Asia. We forget that this condition was so incredibly rare that <a href="http://bmb.oxfordjournals.org/content/56/4/925.full.pdf">the first ever medical study</a> into acute food allergy was in 1969 – just at the time of the moon landings. Now <a href="http://www.kcl.ac.uk/newsevents/news/newsrecords/2015/February/Eating-peanut-at-an-early-age-prevents-peanut-allergy-in-high-risk-infants.aspx">one in 50</a> children in the UK <a href="https://www.sswahs.nsw.gov.au/rpa/allergy/resources/allergy/peanutallergy.pdf">and Australia</a> is affected.</p>
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<img alt="" src="https://images.theconversation.com/files/88668/original/image-20150716-5070-4f3nlq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/88668/original/image-20150716-5070-4f3nlq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=476&fit=crop&dpr=1 600w, https://images.theconversation.com/files/88668/original/image-20150716-5070-4f3nlq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=476&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/88668/original/image-20150716-5070-4f3nlq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=476&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/88668/original/image-20150716-5070-4f3nlq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=599&fit=crop&dpr=1 754w, https://images.theconversation.com/files/88668/original/image-20150716-5070-4f3nlq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=599&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/88668/original/image-20150716-5070-4f3nlq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=599&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">1969: time of first medical study into acute food allergy.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/trawin/4463055923/in/photolist-7Nok34-5rcgSr-5nQ9ig-7Nsjns-7Nsjmj-7Nok9p-7Nsjk3-2vVkpu-bomkZ7-5rgErw-8kf3PF-ooVBBi-6FiSCR-8kf3CB-dSVfXC-s8t3Wt-5rciwc-6FiSGD-67f4e9-3bW8hs-6QRD1u-5rgBJE-5z4NtX-cAtxiU-8VTtpF-6k497p-o4T16c-6FiSEz-8w5ywj-rDtv7w-fBxwtJ-fchUZn-67aPui-6FnZJu-6FnZy7-a5BhGt-67aPCg-8WoXpy-9kD7n8-5H3paU-8VKSYp-qZffRV-67f499-fBiarg-6FiSTn-6FnZuQ-79j4CM-fBxxmA-8Aw8ra-qZfg2z">David Trawin</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>Faced with increasing numbers of young children potentially dropping dead from inhaling nut dust, there <a href="http://edition.cnn.com/2010/TRAVEL/06/22/ban.peanuts.planes/">has been discussion</a> about banning nuts on flights altogether, and <a href="http://www.dailynews.com/social-affairs/20120116/severe-peanut-allergy-prompts-family-to-abandon-lausd-for-palos-verdes-peninsula-schools">worried parents have lobbied</a> to have nut-free schools not only in California – but <a href="http://www.nutmums.com/starting-school-with-a-nut-allergy/">also in England</a>. The problem is that this airborne risk is a myth.</p>
<p>Although nut allergy is real and scary for parents and sufferers – it can’t for practical purposes be transmitted through the air enough to cause these severe reactions. Researching the story for my new book, <a href="http://www.amazon.co.uk/The-Diet-Myth-Science-Behind/dp/029760919X">The Diet Myth</a>, I spoke to several of the world’s leading food allergy consultants including Adam Fox, a consultant in paediatric allergy at St Thomas’ Hospital. He and colleagues who have worked for many years testing thousands of children with severe allergic reactions had “never heard of nut vapours causing these severe reactions”. Peanut particles are heavy and although can form dust on surfaces, studies have been unable to detect peanut particles <a href="http://www.ncbi.nlm.nih.gov/pubmed/23608728">in the air</a> or the key allergens in the air <a href="http://www.ncbi.nlm.nih.gov/pubmed/23406937">in sufficient amounts</a> to cause a reaction.</p>
<p>They all agreed that the plane incident as it was reported could not have occurred however strong the plane air conditioning or the belief of the parents. Her lips or tongue must have touched something else directly. The timing was unfortunate and the exact trigger still a mystery. </p>
<h2>Of mice and mothers</h2>
<p>But why are we going through such an epidemic of food allergies in children? A recent study has shed light on this – and our diet is a likely culprit. </p>
<p><a href="http://www.abc.net.au/science/articles/2015/06/24/4260521.htm">Australian researchers</a> used mice sensitive to allergies and asthma and found they could prevent the risk of young pups being allergic depending on what the mother ate in pregnancy. The higher the fibre content and the more food diversity, the lower the rate of subsequent allergies. What was really novel was that gut microbes were crucial to the process. Pregnant mice with the high-fibre diet had a group of microbes that produced an anti-inflammatory chemical called acetate.</p>
<p>When they looked at human pregnancies, a similar association with dietary fibre was seen with the chemicals produced by microbes. The higher the fibre intake, the higher the acetate levels and the less allergy in their children.</p>
<p>These trillions of different bacteria in our lower guts keep us healthy. They do this by feeding off the fibre from rich foods and converting the nutrients to healthy chemicals that suppress our immune systems. So the higher the fibre content and diversity in meals the better the effect on the immune system. </p>
<h2>Fear of allergies</h2>
<p>Pregnant mothers now are under huge pressure to be healthy - but the advice they get is conflicting. Many with allergic families are told to cut out foods or avoid eating peanuts (there is a common belief that eating peanuts will lead to a peanut allergy in babies later), while others are routinely told to avoid eating French cheese or salamis, raw or undercooked meats because of the risk of very <a href="http://www.theguardian.com/society/2007/may/29/health.medicineandhealth">rare infections</a> that other countries don’t worry about. </p>
<p>In this way they anxiously end up on very restrictive diets, lacking diversity and fibre. These diets could be having the opposite effects to those intended as they starve our gut microbes of nutrients and reduce the immune dampening chemicals they naturally produce. </p>
<p>An increasing trend is that many of us think we have food allergies when we don’t. One study found that <a href="https://theconversation.com/four-myths-about-allergies-you-thought-were-true-but-arent-42855">while 38% of people think</a> they have a food allergy, the real figure is closer to around 1%. This exaggerated fear of allergies means that parents are preventing some children from eating foods such as wheat, nuts, eggs or milk.</p>
<p>Paradoxically, peanut allergy looks like it could be cured by reintroducing tiny amounts of peanuts <a href="http://www.ncbi.nlm.nih.gov/pubmed/25705822">slowly early in life</a>. Early studies <a href="http://www.theguardian.com/science/2015/jan/28/peanut-allergy-researchers-say-they-may-have-found-key-to-a-cure">also suggest microbes can help prevent</a> the allergy as introducing probiotics has also helped. Data so far shows non-allergic mothers who eat peanuts <a href="http://www.ncbi.nlm.nih.gov/pubmed/24366539">are less likely</a> to subsequently have peanut allergic children. And a change of heart may finally be underway after interim guidelines <a href="http://www.dailymail.co.uk/health/article-3219730/Prevent-children-developing-peanut-allergy-feeding-PEANUTS-say-experts-new-guidance-parents.html">issued by the American Academy of Pediatrics</a>, and based on <a href="http://www.kcl.ac.uk/newsevents/news/newsrecords/2015/February/Eating-peanut-at-an-early-age-prevents-peanut-allergy-in-high-risk-infants.aspx">a peanut trial</a> led by Gideon Lack at King’s College London, suggested that babies at high-risk of developing peanut allergy are protected from peanut allergy at the age of five if they eat peanut frequently, starting within their first 11 months. </p>
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<p>So let’s stop banning foods like peanuts and dairy products, and living in hygienic antiseptic bubbles. To extract us from the allergic cycle we are in, we should be encouraging food diversity in our diets from an early age to keep our gut microbes as healthy as possible. We all need to increase consumption of “microbe friendly” foods, a diverse range of fibre-rich and fermented foods including regular nuts and seeds, with less fear about holding back from what children eat.</p><img src="https://counter.theconversation.com/content/44687/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tim Spector is the author of The Diet Myth: The real science behind what we eat.</span></em></p>Severe allergies are on the rise – could our diet be to blame?Tim Spector, Professor of Genetic Epidemiology, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/369012015-02-18T03:32:22Z2015-02-18T03:32:22ZPeanut allergy treatment is on the horizon – but don’t drop the EpiPen yet<figure><img src="https://images.theconversation.com/files/71919/original/image-20150213-13206-vlgpy4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Avoiding peanuts is currently the only way to prevent allergic reactions.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/sharynmorrow/3052699217/in/photolist-5DKT88-53Sm9N-oNomHQ-oNoo2w-93xAGy-62u7wG-bWEvKe-dVMqvf-2nqmq8-9rPN4e-79pjrS-ayw5N5-4E6e8S-niRBmL-4U4cfX-8gHzoq-7vRdJJ-ovW44e-oNonnL-5ihiFa-6AFQ19-niRAHm-7nhGAz-6YVE6n-9nn7Ax-8sQHCK-piZE4i-9VU913-5a4478-5V4V9Z-8JXJrn-NBgcU-5Ubhzm-4wcgcQ-6UC8Tv-4nx5uY-dUtSCJ-bGhKLH-PvRcS-eb9ZMt-b9fM8r-ecj1x-6p5Sor-biKrZ4-6oMbCY-7ADVx8-7mg64d-93uuMp-dYA1YH-AyLw7">sharyn morrow/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Rates of food allergies have increased over recent decades and are at an all-time high. While we don’t know the full extent of the allergy epidemic, the <a href="http://www.ncbi.nlm.nih.gov/pubmed/19217654">rate of hospitalisation</a> for food allergies has quadrupled since the mid-90s.</p>
<p>Peanuts are one of the most common causes of food allergies. The <a href="https://www.mcri.edu.au/research/projects/healthnuts">HealthNuts study</a> tested almost 3,000 Melbourne children born between 2006 and 2009 and found 3% of infants had a confirmed peanut allergy. Only one in five children had grown out of the allergy by four years of age. </p>
<p>Researchers have made some promising steps forward in developing a treatment for peanut allergies, but there is currently no cure. Avoiding the food is the only way to prevent allergic reactions.</p>
<h2>What is a peanut allergy?</h2>
<p>Peanut allergies occur when the body’s immune system develops antibodies – called immunoglobulin (Ig) E molecules – against parts of the “harmless” peanut protein. This is known as sensitisation.</p>
<p>Sensitisation can be easily detected by measuring peanut-specific immunoglobulin E either in the child’s blood or by means of a skin prick test.</p>
<p>Allergy as a disease is seen when IgE antibodies activate the immune system. This may lead to face, lip, eye swelling, welts and hives, breathing difficulties, vomiting, and even collapse of the body’s blood circulation. </p>
<p>The most severe form of reaction, anaphylaxis, can cause swelling of the tongue and throat. This is a potentially life-threatening condition that requires emergency treatment with adrenalin autoinjectors (also known by the brand name, EpiPen).</p>
<p>But not everybody who has IgE antibodies to “peanut” will experience an allergic reaction. </p>
<p>Sometimes peanut sensitisation is found in a child who has never been exposed to peanuts. This is more common in children with eczema or children who have other food allergies. </p>
<p>In other cases, the symptoms cannot be unequivocally attributed to allergy and/or exposure to peanut. In these situations, the question has to be resolved: is it “only” peanut sensitisation or is it a peanut allergy?</p>
<h2>Causes</h2>
<p>The causes of sensitisation are unknown but <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa013536">research suggests</a> it could occur through the skin in children with eczema. </p>
<p>Other factors affecting this meteoric rise <a href="http://fooddrugallergy.ucla.edu/body.cfm?id=40">could be</a> cleaner and more hygienic environments and the delayed introduction of allergenic foods.</p>
<h2>Diagnosis</h2>
<p>If a patient presents with symptoms of allergic reaction after eating peanuts, a positive skin prick test to peanuts or detecting the presence of specific IgE to peanuts by a blood test, will confirm the peanut allergy.</p>
<p>However, if the history is ambiguous or sensitisation is seen in the absence of a known exposure to peanut, the patient may need to undergo a food challenge to confirm the peanut allergy. As this could lead to an allergic reaction, food challenges need to be performed in a clinical setting, where treatment is readily available. </p>
<p>Our <a href="http://onlinelibrary.wiley.com/doi/10.1111/cea.12258/abstract">Newcastle Peanut Anaphylaxis Predictors study</a> showed that the combination of an antibody test and a breathing test that measures a molecule called nitric oxide in exhaled air can avoid the need for a food challenge test in half of the children suspected to have peanut allergy. </p>
<p>Building on this approach, we have developed a blood test to predict anaphylaxis, which is currently being validated in a large population of children with suspected peanut allergy. </p>
<h2>Treatment</h2>
<p>Most children with peanut allergy need to carry an adrenaline autoinjector because it provides immediate relief from severe allergic reactions. </p>
<p>The uncertainty of when a severe reaction will occur places immense psychological and social burdens on patients and families. As a consequence, a number of children with peanut allergy <a href="http://onlinelibrary.wiley.com/store/10.1111/j.1398-9995.2010.02342.x/asset/j.1398-9995.2010.02342.x.pdf;jsessionid=640A3E4F5E182E01F3BDCB58DAAF21A7.f02t04?v=1&t=i636xo7b&s=b60f3b06bed2c02a7304baf21005e2ac22f32ece">suffer from</a> anxiety-based disorders. </p>
<p>Encouragingly, researchers have recently made progress in optimising immunotherapy, also called peanut “desensitisation”. In this process small amounts of peanut protein is administered regularly to build up “tolerance” to the food.</p>
<p>British scientists Leonard Noon and John Freeman were the first to show in 1911 that desensitisation to pollen could be an effective treatment for hay fever. </p>
<p>A century later, a <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060783/">study</a> with 28 children in Durham, North Carolina, showed that oral immunotherapy could reduce allergic reactions to peanut. </p>
<p>This study was subsequently confirmed by the <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2813%2962301-6/abstract">STOP II trial</a> in Cambridge, UK where 62% of children with peanut allergy were able to eat five to ten peanuts without allergy symptoms six months after the initiation of treatment. </p>
<p>Recently, Professor Mimi Tang and co-workers from the Murdoch Childrens Research Institute, Melbourne, <a href="http://www.theatlantic.com/health/archive/2015/01/a-possible-treatment-for-peanut-allergies/385045/">studied</a> an oral probiotic peanut combination immunotherapy in 62 allergic children without previous anaphylaxis. Children enrolled in this study were regularly given small amounts of a peanut and probiotic combination so as to develop tolerance to peanut.</p>
<p>This treatment resulted in 82% of children being “tolerant” to peanuts, meaning they were able to eat roughly 20 to 40 peanuts without allergy symptoms, two to five weeks after the treatment stopped. This suggests that there may be a treatment in the future, which has a sustained effect. </p>
<p>However, treatment side-effects with oral peanut (and probiotic combination) immunotherapy are very common, with 45% to 93% of children affected. That’s why oral peanut immunotherapy can only be provided within high-level specialist care and at present is advisable to do only within research settings.</p>
<p>In future, we hope to be able to use bio-markers to predict whether children who come into contact with peanuts will have anaphylaxis and whether they’ll respond to different treatments.</p><img src="https://counter.theconversation.com/content/36901/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rani Bhatia has received funding from Hunter Children's Research Foundation. She is an inventor on a provisional patent that describes a marker for peanut allergy </span></em></p><p class="fine-print"><em><span>Adam Collison receives funding from Hunter Children's Research Foundation and the Thrasher Research Fund. He is an inventor on a provisional patent that describes a marker for peanut allergy.</span></em></p><p class="fine-print"><em><span>Joerg Mattes receives/has received funding from the NHMRC, Hunter Medical Research Institute, Asthma Australia and the CRC for Asthma. He is an inventor on a provisional patent that describes a marker for peanut allergy.</span></em></p>Rates of food allergies have increased over recent decades and are at an all-time high. While we don’t know the full extent of the allergy epidemic, the rate of hospitalisation for food allergies has quadrupled…Rani Bhatia, Senior Staff Specialist in Paediatric Allergy and Immunology at John Hunter Children's Hospital Newcastle NSW Conjoint Lecturer in Paediatrics, University of NewcastleAdam Collison, Post Doctoral researcher - Experimental and Translational Respiratory Medicine Research Group, University of NewcastleJoerg Mattes, Professor&Chair of Paediatrics | HMRI, University of Newcastle, Australia | Senior Staff Specialist Paediatric Respiratory&Sleep Medicine | John Hunter Children's Hospital, Australia, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.