Cutaneous periarteritis nodosa: a clinicopathological study of 79 cases.

Cutaneous periarteritis nodosa (PAN) is a well-recognized entity characterized by tender subcutaneous nodules and livedo that may ulcerate. The pathogenesis of cutaneous PAN is not known. The objective of the study was to evaluate the clinical and histological features of 79 cases of cutaneous PAN and to investigate any clinical, pathological and immunological differences that may distinguish those cases likely to have a prolonged course. A retrospective analysis of 79 cases was conducted. Thirty-nine patients had ulcers during the course of their illness. Women were affected more than men. Painful nodules on the lower extremities, with oedema and swelling, were the most common clinical finding; 22% of patients had some evidence of neuropathy. Most of the laboratory findings were non-specific. There was no evidence for hepatitis B infection and hepatitis C infection was present in only one patient. Most patients (60%) had no associated medical condition. The disease course was prolonged but benign, and systemic PAN did not develop in any patient. Corticosteroids given systemically induced remission in most acute cases. The ulcerative form of disease was more prolonged and frequently associated with neuropathy.