A total of 320 children with atopic dermatitis undergoing double-blind, placebo-controlled food challenges (DBPCFC) for the evaluation of food hypersensitivity were monitored for respiratory reactions. The patients, ages 6 months to 30 yr, were highly atopic (median IgE; 3,400 IU/ml) and had multiple sensitivities to foods and aeroallergens. Fifty-five percent of the patients had asthma; 45% presented with both asthma and allergic rhinitis. Food hypersensitivity was confirmed by DBPCFC in 205 (64%) of the 320 patients evaluated, and 121 (59%) of these 205 patients experienced respiratory reactions, including nasal, laryngeal, and/or pulmonary symptoms in 34 (17%). To assess the degree of pulmonary dysfunction developing during food hypersensitivity reactions, especially those including lower respiratory symptoms, 88 of these patients were monitored with spirometry during positive and negative DBPCFC. Of these patients, 13 (15%) developed lower respiratory symptoms, including wheezing, during DBPCFC; however, only six patients had a > 20% decrease in FEV1. We conclude that respiratory symptoms are commonly provoked in children with atopic dermatitis during DBPCFC, but significant bronchopulmonary obstruction is not frequently observed.