The turning point came last year with the LEAP (Learning Early About Peanut) Study published in the New England Journal of Medicine. This five-year study showed that avoidance of food allergens by children at risk for food allergy is often the wrong strategy, which, of course, is contrary to something doctors had been advising for decades.
Data in the study were so powerful that doctors have already changed the advice they are giving to parents with children pre-disposed to food allergies. Meanwhile, the American Academy of Allergy and Immunology together with the American College of Allergy and Immunology are working with the National Institutes of Health to firm up a position paper to formalize these new recommendations.
Researchers with the Immune Tolerance Network conducted the LEAP Study by enrolling hundreds of infants from four to 11 months old who were predisposed toward peanut allergy. Children in the study were not yet sensitized to peanuts, but they had the family history plus a strong sign of developing food allergies—severe eczema. It is likely that eczema is associated with food allergies because breaks in the skin allow allergens to sensitize children.
Children in the study were divided into two groups. One group was fed peanuts daily, and the other group strictly avoided peanuts. After five years, researchers looked at which children had become allergic to peanuts and which had not. Only about two percent in the group that was exposed repeatedly to peanuts developed a peanut allergy. By contrast, nearly 14 percent of the children in the peanut avoidance group developed allergies. We seldom see differences like that in human studies. It was striking and statistically significant.
So there’s a new recommendation for infants at risk for food allergies. We can do testing, of course, and if they are not already allergic and are able to tolerate the food allergen, we are recommending that they should be fed the food frequently. That is the opposite of the previous recommendation, which warned parents to avoid exposing children to potentially allergenic foods for as long as possible.
For children who have already developed food allergies, some hopeful trials are underway that may offer protocols for desensitization. This approach would be similar to how allergists desensitize people who are allergic to pollen. Pollen desensitization is usually done with injections, but that’s dangerous for people with food allergies. With food allergies, the desensitization would be attempted with a graded, oral protocol. These are being developed for egg, nut and peanut allergens.
Patients would be challenged in clinic to see how much of an allergen they can tolerate. Then a patient will consume that amount daily, possibly increasing that amount according to how they fared in subsequent challenges. Researchers have found that food tolerance gradually increases in most patients. In about a third of cases, patients can become completely desensitized, even those who had severe allergic reactions. A majority of patients are desensitized to the point that they can tolerate a small amount of allergens safely. That substantially lowers risks for severe, life-threatening allergic reactions.
Obviously, there is great interest in these protocols since about five percent of children have food allergies. We expect to have the new protocols available in general clinical use in the not-too-distant future.
This changing paradigm about food allergies is making doctors take a second look at why food allergies have been increasing. Most likely doctors have been contributing to this pattern by giving new mothers the wrong advice. Until the LEAP Study, we just didn’t have the data to make a good scientific recommendation, so we depended upon logic and common sense. We turned out to be wrong.
I strongly suspect that the incidence of food allergies in children will begin to subside after new recommendations take effect.
It’s also worth mentioning that there are some new biologic drugs in the pipeline that are promising for children with severe allergic asthma. We’ve been using one of these injection drugs, Xolair (omalizumab), for about a decade. Now, new ones will be available soon and some are effective at controlling severe asthma and even severe hives.
These new drugs will be expensive, but for people who are often hospitalized with severe asthma, they may be cost-effective and could certainly improve their quality of life.
Prescott Atkinson, MD is Director of Pediatric Allergy and Immunology at Children’s of Alabama and a Professor of Pediatrics at UAB. He is board certified in pediatrics, as well as allergy and immunology.