Food allergies are a growing public health concern. Learn about why food allergies are on the rise, what you can do to prevent allergies and how to manage childhood food allergies from internationally recognized pediatric food allergy expert Wesley Burks, MD, chief physician of NC Children’s Hospital.
The Rise in Food Allergies
Q: Has there really been an “explosion” in childhood food allergies? Or are parents just more sensitive to the issue?
A: The rise in food allergy prevalence is a real phenomenon. 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 any trends in the variety or severity of food allergies?
A: 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. We also 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 food allergies are increasing because we’re raising our children in a “too clean” environment. Does research support this?
A: The hygiene hypothesis is the idea that our immune systems, 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 farms with livestock—have a low propensity toward allergies. But in 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.
Preventing Food Allergies
Q: Can a mother’s diet while pregnant or nursing affect the 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 can parents do to reduce a 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 toward allergic disease. Beyond that, there’s not a recommended or “right” way to introduce 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.
Caring for a Child With a Food Allergy
Q: What advice do you have for parents caring for a child with a food allergy?
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 allergic to only one or two foods, not a huge list.
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: Do children outgrow food allergies?
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 for most kids, once they develop a peanut allergy, they do not outgrow it.
The good news is that there are different types of immunotherapy studies going on here at UNC Children’s through the UNC Food Allergy Initiative, as well as nationally and internationally. Different treatments are being developed that I really do think will change how we treat patients in the next few years. There’s lots of promise in those studies, and we’re hopeful those advances will signify big changes in the not-so-distant future.