is it really a food allergy?

It seems every time you turn around these days, there is a new food allergy in the news. There are horrific stories of kids who cannot even be in the same room as a peanut. Gluten-free products have sprung up all over the supermarket shelves. You probably know someone who is lactose-intolerant. The question is, are food allergies really more prevalent these days? A group of researchers did an exhaustive research review to get to the heart of the matter.

Their report, commissioned by the federal government and published in the May 12 issue of The Journal of the American Medical Association (2010; 303 [18], 1848–56), found that the field of allergy research is full of poorly conducted studies, misdiagnoses, and tests that can give misleading results. Researchers concluded that the evidence for the prevalence and management of food allergy is greatly limited by a lack of uniformity in the criteria used for making a diagnosis.

For their report, the authors reviewed more than 12,000 food allergy papers published between January 1988 and September 2009. In the end, only 72 met the researchers’ criteria, which included having sufficient data for analysis and using more rigorous tests for allergic responses.

From the worthy studies, the scientists gleaned that food allergy affects more than 2% but less than 10% of the population. It was unclear whether the prevalence of food allergies is increasing and also whether one method of food allergy detection (skin prick versus serum food-specific IgE) is statistically superior to the other. Although elimination diets (physician orders not to eat certain foods) are the mainstay of therapy, the review revealed that this method has rarely been studied. Immunotherapy is promising, but data are insufficient to recommend its use.

The paper is part of a large project organized by the National Institute of Allergy and Infectious Diseases to try to impose order on the chaos of food allergy testing. An expert panel will provide guidelines defining food allergies and giving criteria to diagnose and manage patients’ conditions.