Hypocomplementemic urticarial vasculitis in mixed connective tissue disease.

Urticarial vasculitis is characterized clinically by urticaria-like skin lesions and histologically by leukocytoclastic vasculitis. It may be idiopathic or associated with various conditions such as infections, hematologic disorders, drugs, and connective tissue diseases, primarily systemic lupus erythematosus; an association with mixed connective tissue disease (MCTD) has rarely been reported. We present a case of hypocomplementemic urticarial vasculitis in a patient with MCTD that responded to hydroxychloroquine after a period of corticosteroid dependence.