A large number of diseases can eventuate in cutaneous ulceration. This article will review inflammatory disorders which by their nature can directly produce cutaneous breakdown and ulcer formation. Major emphasis is given to those disorders where recent knowledge has improved our understanding of the condition or where new therapeutic agents or maneuvers have become available. This later group consists of vasculitis, disorders caused by small vessel thrombi or embolus and pyoderma gangrenosusm. 1993 American Society for Dermatologic Surgery, Inc.