Nine percent of children allergic to almonds, pecans, cashews and other tree nuts outgrow their allergy over time, including those who've had a severe reaction such as anaphylaxis shock, according to researchers at the Johns Hopkins Children's Center.
Their study, reported in the November issue of the Journal of Allergy and Clinical Immunology, also found that clinicians can use blood levels of tree nut antibody (TN-IgE) as an accurate guideline in estimating the likelihood that a child has outgrown the allergy.
"What's crystal clear is that children with these allergies should be regularly re-evaluated," researchers concluded.
"Allergic reactions to tree nuts as well as peanuts (which are not nuts but legumes) can be quite severe, and they are generally thought to be lifelong," says senior author Robert Wood, M.D., director of the Division of Allergy and Immunology at the Children's Center. "Our research shows that for some children, however, lifelong avoidance of these nuts, found in countless food products, may not be necessary."
In the United States, an estimated one to two percent of the population is allergic to tree nuts (almonds, pecans, walnuts, cashews, Brazil nuts, hazelnuts, pine nuts, pistachios and macadamia nuts), peanuts or both. Wood and colleagues previously reported that as many as 20 percent of children outgrow peanut allergy and recommended that allergists periodically retest their patients. The current study explored whether the same held true for tree nuts.