Clinical response and side-effects in the treatment of psoriasis with UV-B and -A novel dithranol formulation.

A new dithranol formulation (Dithranol-Biogram), in which the dithranol is microencapsulated by crystalline monoglycerides, has been developed. This stable formulation has pharmaceutical and cosmetic properties which overcome several draw-backs associated with conventional dithranol preparations. The clinical efficacy and side-effects of Dithranol-Biogram were compared to a conventional ex-tempore formulation in the treatment of 33 patients at a day-care centre. The study was designed as a randomized, single-blind, within-patient comparison. Patients were treated 4 times weekly for up to 6 weeks. Each session started with suberythematous UV-B doses followed by application of 1% dithranol for 20 min. There was no difference in clinical efficacy between treatments. Within 2-6 weeks the lesions in 21 of the 33 patients were classified as healed. The average reduction in severity score was 39%, 62% and 79% after 2, 4 and 6 weeks, respectively. The incidence of perilesional irritation was, however, several times higher for the ex-tempore treated sides. At the end of the study 21 patients preferred the Dithranol-Biogram formulation, 6 the ex-tempore formulation and 6 had no preference. The results of this study suggest that this novel formulation may become an important contribution to the management of psoriasis.