Urticarial vasculitis in systemic lupus erythematosus: fair response to prednisolone/dapsone and persistent hypocomplementemia.

Two cases of urticarial vasculitis (UV) accompanying systemic lupus erythematosus (SLE) are reported. Both patients developed characteristic wheal and purpuric lesions of UV followed by pigmentation, and histological examination revealed leucocytoclastic vasculitis. Although oral prednisolone was beneficial for the systemic symptoms and various serological abnormalities, one patient needed dapsone and the other needed dapsone and cyclophosphamide to control the UV. In both patients, hypocomplementemia with no evidence of congenital complement deficiency or complement consumption persisted even after all other laboratory data and symptoms improved.