Cutaneous Polyarteritis Nodosa: Uncommon and Rare Form of Cutaneous Vasculitis

Cutaneous polyarteritis nodosa (CPAN) is a variant of polyarteritis nodosa that is limited primarily to the skin. It is a chronic recurrent disorder characterized by the presence of nodular lesions with or without ulceration on the distal third of the lower limbs. Nodular vasculitis and thrombophlebitis can be clinically or pathologically mistaken for CPAN. We present a case of a 51-year-old woman with painful nodules on the lower limbs. Some of the nodules were ulcerated. Histopathological examination of a nodule on deep incisional biopsy revealed fibrinoid necrosis of a medium-sized artery in the subcutis along with perivascular mixed infiltrate. The patient did not have any symptoms or signs of internal organ involvement. The possible etiological factor has not been detected. The patient was treated with oral prednisone 0.5 mg/kg/day and dapson 150 mg/day. Over the one-year follow-up the lesions showed regression, with one minimal relapse which resolved after the short course of oral prednisone.