Chronic cutaneous granulomatous dermopathy: morphologic and serologic evaluation, differential diagnosis and pharmacologic control.

We report on a syndrome of disfiguring lower extremity cutaneous lesions of 6 years duration. Previous medical evaluations included 5 skin biopsies and several therapeutic regimens which did not alter the course of illness. The histologic interpretations of skin biopsies included panniculitis, papulonecrosis, and granuloma. One biopsy was interpreted as a localized cutaneous vasculitis with a wedge-shaped infarct. Infectious, collagen vascular, and factitious etiologies could not be demonstrated to explain the patient's lesions. The Chicago Dermatological Society included in their differential diagnosis bacterial allergy, including the tuberculoid reaction. Mycobacterium tuberculosis as the etiology was dismissed by negative cultures, histologic staining and failure of response to antituberculous therapy. Our report includes a series of immunologic tests that might be consistent with but do not definitively establish a bacterial hypersensitivity reaction to explain this patient's skin lesions. Despite a lack of proven etiology dramatic improvement occurred with corticosteroid therapy.