Cutaneous polyarteritis nodosa.

Classic polyarteritis nodosa (PAN) is a segmentary leucocytoclastic vasculitis that affects small- and medium-sized arteries. In 1931, Lindberg (Acta Med Scand 1931; 76: 183-225) described the existence of a cutaneous variant of PAN, without visceral involvement and with a more favourable prognosis. We present four patients diagnosed with cutaneous PAN in our hospital between 1987 and 1998. The study group was composed of three women and one child, whose ages ranged from 11 to 70 years old. The follow-up period was between 2 and 13 years. Each patient was submitted for an initial clinical, histological and laboratory evaluation and subsequent follow-up. The presence of nodules was the most frequent cutaneous lesion, preferentially located in the lower limbs. The erythrocyte sedimentation rate was the only parameter that was altered in all patients. Cutaneous biopsies from all patients showed a segmentary leucocytoclastic vasculitis in the arteries of the deep dermis and/or hypodermis. Direct immunofluorescence was positive in just one patient. No visceral involvement was found in any patient. There is confusion about the correct definition of cutaneous PAN. Some clinical findings, such as nodules or livedo reticularis, typical of cutaneous PAN suggest a good prognosis; however, we consider that it is necessary to evaluate these patients for systemic involvement for the possibility of arteritis in other organs as the term polyarteritis suggests.