The use of patch testing in the diagnosis of food allergy.

Diagnosing food allergies can be challenging to the practitioner. Our armamentarium includes standardized skin prick testing, radioallergoimmunosorbent (RAST) testing, and food challenges. These methods have certainly been helpful in the IgE-mediated disorders, including urticaria and anaphylaxis. However, diagnosing patients who have the non-IgE (cell-mediated) or mixed (IgE and cell-mediated) disorders remains challenging with our current diagnostic methods. Recent studies have examined the use of patch testing for these food-allergic patients, specifically those with atopic dermatitis and eosinophilic esophagitis. In this article, we review literature regarding patch testing: its methods, its statistical usefulness, and its potential future role.