Dapsone in Behçet's disease: a double-blind, placebo-controlled, cross-over study.

The study was designed to investigate the effects of dapsone in the treatment of mucocutaneous manifestations of Behçet's disease and the possible prophylactic role of dapsone in a double blind/placebo controlled clinical trial. Twenty patients diagnosed according to the International Study Group criteria as Behçet's disease were included in the study. Patients were randomly allocated to receive either dapsone 100 mg daily or placebo for three months in a double-blind manner. After three months, patients were crossed over and followed for a further three months. Patients were followed up in each visit by assessing the number, size, duration and frequency of oral and genital ulcers, other cutaneous manifestations, and systemic manifestations of the disease. A pathergy test was done on each visit. Laboratory investigations included hemoglobin concentration, white blood cell count, ESR, and C-reactive protein. In dapsone-treated patients, there were significant reductions in the oral and genital ulcer parameters as well as the incidence of other cutanous and systemic manifestations. In the placebo-treated group, there were no significant changes in these parameters. The pathergy test result as well as those of other laboratory tests were all decreased in the dapsone-treated group. Although this study was a small scale study, it shows that dapsone was effective in treatment of mucocutaneous manifestations of Behçet's disease and possibly in prophylaxis against systemic manifestations of the disease. This result should lead to a larger scale study with a longer duration of follow-up.