« The Real Facts on Food Allergy Trends? | Main | Mayo Clinic on Outgrowing Peanut Allergy »

December 19, 2005

Outgrowing Child Food Allergy Study

Source: Johns Hopkins Medical Institutions

Researchers at the Johns Hopkins Children's Center in a study reported in the Journal of Allergy and Clinical Immunology have found that 9 percent of children with child food allergies to almonds, pecans, cashews and other tree nuts outgrow their allergy over time. This is true even for those who've had a severe reaction such as anaphylaxis shock. This conclusion does not include peanuts.

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.

"Allergic reactions to tree nuts as well as peanuts can be quite severe, and they are generally thought to be lifelong," says senior author Robert Wood, 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. Tree nuts include almonds, pecans, walnuts, cashews, Brazil nuts, hazelnuts, pine nuts, pistachios and macadamia nuts. 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.

Wood and colleagues evaluated 278 children with a known allergy to tree nuts. Nine percent passed oral food challenges, the standard test to prove a child has outgrown a food allergy. Fifty-eight percent of children with TN-IgE levels of 5 kilounits per liter or less also passed the challenge. The study also found that children who are allergic to more than one type of tree nut are unlikely to outgrow their allergy.

"These findings give allergists a safe guideline in deciding whether to advise their patients to continue avoiding tree nuts, or whether it's time to try an oral food challenge to see if they've outgrown the allergy," says Wood. He cautioned that oral food challenges should be presented only under the close supervision of an allergist.

Posted by David at December 19, 2005 9:20 AM