Topical therapy of alopecia areata with squaric acid dibutylester.

The efficacy of the topical allergen squaric acid dibutylester (SADBE) was investigated in the treatment of twenty-six patients with alopecia areata or alopecia totalis. The patients had their disease for a mean duration of 8.3 years (range, 3 months to 27 years). Sensitization was attempted with 2% SADBE in acetone. Five individuals could not be sensitized. The twenty-one sensitized patients were treated with topical applications of 0.001% to 1.0% SADBE in acetone adjusted to produce and maintain dermatitis for an average of 21 weeks. Eleven (52%) had excellent responses consisting of complete regrowth in six and cosmetically acceptable regrowth in five. The average treatment time for regrowth was 11 weeks (range, 5-20 weeks). Ten (48%) had no clinical response after an average of 19 weeks of therapy (range, 4-42 weeks). Topical SADBE is an effective therapy for some patients with long-standing alopecia areata.