Sustained dapsone-induced remission of hypocomplementemic urticarial vasculitis--a case report.

Hypocomplementemic urticarial vasculitis (HUV) is often misdiagnosed. The response to drug therapy may be unsatisfactory, and immunosuppressive therapy may be associated with significant side effects. A 35-year-old patient whose condition was resistant to cyclophosphamide, corticosteroids, pentoxyphylline, cyproheptadine, sulindac, and colchicine was maintained in remission with dapsone, which may be the drug of choice for HUV. Emphysema has been reported to complicate HUV, but this is the first account of vasculitis-related emphysema with no confounding history of tobacco smoke exposure. The relationship of proteolytic injury to the pulmonary and other manifestations is considered, as is the possible role for dapsone in reducing it.