Widespread pruritic plaques in a patient with subacute cutaneous lupus erythematosus and hypocomplementemia: response to dapsone therapy.

We describe a patient with subacute cutaneous lupus erythematosus, widespread pruritic papulosquamous plaques, and hypocomplementemia. Skin biopsy specimens revealed liquefaction degeneration and colloid bodies and dyskeratotic cells in basal and suprabasal layers. An immunofluorescence study revealed deposits of IgG, IgM, and C3 at the dermalepidermal junction in a bandlike pattern, and particulate IgG deposition in the basal and suprabasal layers. Treatment with prednisolone (15 mg/day), chloroquine phosphate (200 mg/ day), cyclosporine (5 mg/kg daily), and gold (10 mg/day) failed to reduce pruritic plaque formation, and pulse methylprednisolone therapy led to only a transient remission. Clinical exacerbations correlated with a decrease in complement levels. The disease was successfully controlled with dapsone (75 mg/day) and prednisolone (25 mg/day).