Double-blind food challenge in the diagnosis of food sensitivity in the adult.

This study is an attempt to determine the role of double-blind food challenge (DBFC) in suspected food sensitivity in the adult as compared wih established tests of food allergy, including the skin test, RAST, and leukocyte histamine release (LHR) to specific food antigens. Twenty-two subjects (ages 18 to 67) with histories of reactions to foods were challenged with freeze-dried food or placebo in opaque dye-free capsules, in increasing doses over a 90 min span to a total of 13 to 15 gm. This was repeated twice at weekly intervals by similar DBFC. DBFC was preceded by skin testing and venapuncture for RAST and LHR studies. Patients were kept under observation for 2 hr, after which each was asked to maintain a detailed diary of related symptoms and food ingested over the following week. Of 46 DBFCs, 13 (21%) were positive. The correlation with positive skin tests and positive DBFC was 4/13 (30%). The correlation with positive LHR and positive DBFC was lower at 2/13 (15%), and 1/13 (7.6%) with RAST. We concluded that DBFC is an effective test of adult food sensitivity compared with tests usually performed and should be used when the diagnosis is in doubt.