Evaluation of IgE-mediated food hypersensitivities.

During the past 25 years the diagnostic assessment of IgE-associated food hypersensitivity has improved substantially. The double-blind placebo-controlled food challenge has become the "gold-standard" against which all other diagnostic approaches can be measured. Having a standard which gives a correct answer almost all of the time, has enabled us to move to more accurate diagnoses in both the clinic and the laboratory. Food allergy has gone from being a medical mystery to being a clear component of allergy evaluation. Histories are obtained from patients which may be used to design food challenges. The role of skin testing and its interpretation has moved from the fringe to having a central role in eliminating foods incriminated as causes of immediate-onset allergic reactions. The material used for skin testing for foods has improved and we have learned when we must use fresh substances to supplement the commercial extracts. Recently the CAP radioallergosorbent test has shown promise in raising the probability of food reactions to the point that for a few foods in specific individuals, challenges may not be needed. Progress in this area will continue. We have been able to clarify which foods have a high probability of producing symptoms and which foods and which constellation of complaints are unlikely to be confirmed. These patterns of food allergic reactions have now been reproduced in many research centers throughout the world giving us confidence in their validity.