Internationally renowned pediatric food allergy expert, Dr. Wesley Burks, chief physician of N.C. Children’s Hospital and chair of the UNC Department of Pediatrics, sat down for an insightful interview exploring the facts and myths of childhood food allergies.
Q: Is the “explosion” in childhood food allergies a real phenomenon or is there simply a perception that food allergies are on the rise as parents become more sensitive to the issue?
A: The rise in food allergy prevalence is a real phenomenon that isn’t completely understood. We’ve seen a doubling over the last 15 to 20 years, and while the exact reasons behind that increase are still under study, it’s most likely a combination of reasons, with different changes in our environment playing a big part.
Q: Are you seeing troubling trends in the variety or severity of food allergies that accompany the increase in prevalence?
A: Overall, there’s more allergic disease in general—more asthma, more allergic rhinitis, more eczema, as well as more food allergies. Food allergies, however, seem to be growing at a faster pace, but the types of foods we react to are primarily the same ones we’ve always reacted to. In children, it’s the big three: milk, egg and peanut. While the allergy population is larger, we see the same distribution in the severity of reactions, from mild to severe. That is, as more kids are developing food allergies, we are seeing more severe reactions, but percentage-wise kids aren’t having more severe reactions than we’ve seen in the past.
Q: There’s a theory that perhaps we in the western world are raising our children in too clean an environment and that perhaps that is a significant factor in the rise of food allergies. Does the research support this supposition?
A: The Hygiene Hypothesis is the idea that our immune system, as a result of not having to fight off as many viral and bacterial infections in an industrialized society, are hypersensitive and left to see the allergens in our environment as foreign and then react to them. There are some really good studies from Eastern Europe showing agrarian families, those living on the farms with livestock, have a low propensity toward allergies. But then study of various environments here in the U.S., places where we might see less stringent cleanliness and hygiene, the theory is not bearing out. So there are parts of the hypothesis that make sense and parts of it that really don’t. When we consider environmental factors, there are many things at play. The changing microbiome in our GI tracts, for example, the natural flora and fauna in our bodies, that’s a big part of our immune system. Then there’s the air that we breathe, and the different pollutants in the air, those things are really changing and playing a part in our immune system and how it reacts.”
Q: Is there any evidence a mother’s diet during pregnancy or while nursing can help prevent, or could possibly exacerbate, the eventual development of food allergies?
A: There aren’t any good studies to suggest that avoidance or incorporation of certain foods while pregnant or nursing influence the eventual outcome. If the baby is found to be allergic to a particular food, however, a nursing mother needs to avoid that food, because it can be passed to the baby through the breast milk.
Q: What about after the child is born? Is there anything parents can do to reduce the child’s risk of developing a food allergy?
A: There are two strategies that lessen a child’s risk for developing allergic disease—not just food allergies, but all across the board. The American Academy of Pediatrics encourages mothers, whenever possible, to breastfeed until six months of age and to avoid introducing solid foods until six months old. If you do those two things, you won’t eliminate the risk entirely, but the child will have less prevalence towards allergic disease. Beyond that, there’s not a recommended or “right” way to introduce the allergenic foods. Any time after six months, if you want your child to have any food, provided it’s age-appropriate, then it’s fine to offer it.
Q: What about parents who have a child who’s already developed a food allergy? What advice do you have for them?
A: The best strategy—the right treatment plan as of right now—is proper diagnosis. Parents and caregivers have to know, what specific food triggers the allergic reaction? Most kids affected by food allergies are only allergic to one or two foods, not a huge list. The difficulty is that many of the diagnostic tests we use to identify food allergies are really good negative predictors of food allergy but not great positive predictors, so that leads to some confusion. Once the food allergy has been defined, vigilant avoidance of that food is important, especially ingestion. A child can certainly have a lesser reaction through contact with the allergenic food, but life-ending reactions are always by ingestion. Finally, parents must always be prepared for accidental reactions. Half of children diagnosed with a food allergy will have an accidental reaction within 18 months. Accept it, and be ready to react quickly.
Q: What hope can you offer parents who have a child with a food allergy?
A: Children often outgrow food allergies, particularly those with milk and egg allergies. The process takes longer than we previously thought, but it’s very uncommon for a child to go to college with a milk or egg allergy. Peanuts are different. There are a small number of kids who will outgrow peanut allergy, but unfortunately, once they develop it, most do not outgrow it. The good news is that there are different types of immunotherapy studies going on nationally and internationally, different types of treatment that are being developed now, that I really do think will change how we treat patients in the next few years. We’re not quite there yet, but there’s lots promise in those studies, we’re hopeful those advances will signify big changes in the not so distant future.
* This article was reprinted with permission from UNC Children’s News › CARE e-Newsletter › 2014 › Issue 6 › Childhood Food Allergies: Exploring the Facts and Myths. Contact them at: Email: firstname.lastname@example.org
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Cathy Fox, M.S., OTR/L says
Great information. Nicely presented and focused.