The efficacy of ketotifen in a controlled double-blind food challenge study in patients with food allergy.

The effectiveness of oral ketotifen was compared with that of placebo in 26 patients with food allergy in a randomized, double-blind parallel study. Patients were selected on the basis of food allergy as established by history, clinical improvement after an exclusion diet, and reappearance of the symptoms after a challenge with the food. Thirteen patients were given ketotifen and 13, placebo. Ketotifen or placebo were administered twice daily for 1 month after the first oral provocation test and the last dose was given 12 hours before the second oral provocation test. Ketotifen protected patients (7/13) significantly more than placebo (2/13; P less than .05). The results of this study suggest that ketotifen may be useful for some patients with food allergy.