We often think about ordering serum IGE (sIGE) studies when we are worried about food allergies developing, especially in a child with atopic dermatitis. Yet, how predictive is a serum IgE for diagnosing food allergies? To answer that question, Spergel et al. (dx.doi.org/10.1542/peds.2015-1444) followed patients with atopic dermatitis and no prior history of food allergy over time to see if baseline IgEs to a host of common food allergy triggers (e.g. cow’s milk, egg white, peanut, wheat, seafood and soybean) or subsequent IgEs drawn as part of an open label trial of a randomized double-blinded pimecrolimus cream trial for atopic dermatitis predicted food allergies.
Sadly the results of this secondary study from the trial are less than desirable in that IgEs are far less predictable than you would like to see in diagnosing or monitoring for food allergies. If you have been using IgEs to monitor for the possible development of food allergy, you may find this test does no more than scratch the surface in making the diagnosis after reading this study.
You’re probably itching to read it now—so go ahead—but please let us know if you agree with the findings in your own patients by responding to this blog, sending us an e-letter, or posting your thoughts on our Facebook or Twitter websites.
