Urticarial vasculitis: an updated review.

Urticaria and vasculitis are two different reaction patterns in the skin. Both are caused by a wide variety of substances involving different pathogenic mechanisms. Recently isolated cases of "urticarial vasculitis" have been reported. These cases involve patients who present with a clinical picture of urticaria which, by skin biopsy, shows necrotizing vasculitis. The probable underlying pathogenic mechanism in this condition is one of immune complex deposition. This review will analyze the clinical, laboratory, and immunopathologic features of these patients and then will develop an overall concept of what constitutes "urticarial vasculitis."