BACKGROUND Cysteinyl leukotrienes have been shown to be important in the pathogenesis of allergen-induced (atopic) asthma and rhinitis. Skin manifestations of atopic dermatitis have been reported to improve with leukotriene antagonists. Montelukast, a newer leukotriene antagonist, which is efficacious and safe in patients with asthma 6 years of age and older, has not been reported as therapy for atopic dermatitis. This article reports findings from a pilot study designed to determine whether montelukast is effective in decreasing the signs or symptoms of atopic dermatitis. OBJECTIVE Our purpose was to compare the efficacy of montelukast with placebo as a treatment for patients with atopic dermatitis. METHODS The study involved 8 adult patients (male and female) with at least 1 year of intermittent or persistent atopic dermatitis as determined by Hanifin criteria. Medication was given in a randomized, double-blind, placebo-controlled, crossover manner over 8 weeks as adjunctive treatment. Global evaluation of 6 signs (erythema, induration, excoriation, lichenification, scaling, erosion) were scored on a 0 to 3 scale each week, with a blinded investigator evaluating at the initiation, crossover, and final visit. A 30% decrease in total score was considered clinically significant. RESULTS A significant difference in atopic dermatitis scores between placebo and active agent (P =.014) was recognized. There was no significant interaction between order and treatment. Atopic dermatitis scores tended to be higher with placebo. The mean standard deviation was 8.7 +/- 2.0. The mean for active agent was 6. 8 +/- 2.1. CONCLUSIONS This study demonstrates that there is a modest, but significant, alleviation of atopic dermatitis with the use of the leukotriene antagonist montelukast used in an adjunctive manner over a 4-week period.