Peanut Allergies: Outgrowable?

By Sora Song

Until recently, most doctors believed that peanut allergies, which affect some 1.5 million Americans and can be deadly, were a lifelong affliction. Now it turns out that some people outgrow them. As part of an ongoing study of peanut intolerance, Johns Hopkins researchers gave 80 allergic children a "peanut challenge"--that is, they made them eat peanuts. More than half the kids passed the test, suffering none of the common allergy symptoms, such as hives, vomiting or swelling of the face and lips. The study, published in this month's Journal of Allergy and Clinical Immunology, looked at children with low levels (5 kilounits or less per liter of blood) of peanut-specific IgE--the antibodies that cause allergic reactions--and found that the lower the levels, the more likely the children were to outgrow their peanut sensitivities. These antibodies can be measured with widely available blood tests, and the study's authors recommend that peanut-intolerant kids get tested every year or so. Researchers also say children may be given peanut challenges starting at about age 4, but only under a doctor's supervision. --S.S.