Food allergy challenges: guidelines and implications.

Double-blind placebo-controlled food challenges were used to determine the presence or absence of food hypersensitivity in 120 children with atopic dermatitis. Foods to be challenged were selected on the basis of history, allergy skin tests, nutritional significance, and patient desires. Dehydrated foods were hidden in capsules or juice and administered twice a day. Antigens were obtained commercially or prepared through a process of freeze-drying and subsequent pulverization. Cutaneous, gastrointestinal, nasal, and/or respiratory symptoms occurred following 133 challenges. Although patients exhibited multiple positive skin tests to foods, 86% experienced a positive response on blinded challenge to only one or two foods. Double-blind placebo-controlled food challenges accurately diagnose food hypersensitivity and minimize the number of foods eliminated from allergy avoidance diets. A new method of elimination diet management and education is based on the identification of "key words" on food labels. Instructional diet sheets were developed to teach this concept, which was found to promote greater confidence, compliance, and creativity in diet planning.