Q: I’m a teacher with a daughter in high school who has allergies to dairy and soy. When she was little, the pediatrician said: “She’ll outgrow the milk allergy.” She hasn’t, and last year had a serious reaction. At my school I’m now seeing kids in fifth and sixth grades with dairy allergies. Is there an age at which you’ll no longer outgrow this allergy?
Dr. Sharma: Recent studies have found that cow’s milk allergy is persisting longer than previously thought. First, it’s important to distinguish between the potentially anaphylactic type of dairy allergy, in which milk protein sets off the response of IgE antibodies, versus the gastrointestinal forms of the allergy, which do not involve IgE.
The non-IgE-mediated forms of milk allergy trigger symptoms such as blood in the stool, vomiting, and abdominal pain in infants or toddlers, and are almost always outgrown during early childhood. In contrast, research has shown the IgE-mediated milk allergy may persist into adolescence and adulthood.
A 2007 John Hopkins University study of 807 children showed the more serious type of milk allergy was enduring much longer than had been previously reported. But importantly, it also demonstrated that the condition could be outgrown as late as adolescence. The allergy resolved in 19 percent of the children at 4 years of age; 42 percent of kids by age 8; 64 percent by age 12; and 79 percent at 16 years old.
Certain factors may suggest which children are less likely to outgrow the allergy. For example, those with higher peak milk IgE levels tend to have a more persistent allergy.
Also, children with asthma, allergic rhinitis, and severe eczema are more likely to have a long-term allergy. In the future, tests that detect IgE against certain components, or “epitopes,” of the cow’s milk protein may better predict who is likely to have a enduring allergy.
For teens like your daughter who still have a milk allergy, it’s important to continue follow-up and re-evaluation with your allergist, for example with repeat IgE blood testing. As seen in the Hopkins study, children may not see the dairy allergy resolve until as late as adolescence.
You can also discuss with the allergist whether to pursue an oral food challenge to extensively heated or baked milk products. For some children, the introduction of heated milk, if tolerated, may accelerate the resolution of the allergy.
Dr. Sharma is an allergist, clinical researcher and assistant professor of pediatrics. He is Clinical Chief of the Division of Allergy and Immunology at Children’s National Health System in Washington, D.C. and Director of the Food Allergy Program. Questions submitted below will be considered for answer in the magazine.