Two cases of unilateral pigmented purpuric dermatosis

Abstract

Two cases of pigmented purpuric dermatosis showing unusual distribution are reported. Case 1: 35-year-old female. A group of three asymptomatic purpuric macules developed on the ulnar side of the elbow flexure of the left forear 3-6 months before presentation. Histopathological analysis revealed a band-like inflammatory infiltrate in the Uppermost dermis and extravasation of red blood cells just beneath the epidermis, but there was no evidence of lichefaction degeneration in the basal layer of the epidermis. Case 2: 26-year-old female. Asymptomatic purpuric pigmentations developed on the flexure side of the right lower extremity in a linear arrangement 2-3 months before presentation. Histopathological analysis revealed focally perivascular inflammatatory infiltrates consisting mainly of lymphocytes and conspicuous extravasation of red blood cells into the papillary dermis. There was no histological evidence of vasculitis in either case. Hemosiderin deposits were more limited than expected in both patients. Both cases are compatible with diagnoses of pigmented purpuric dermatosis. Case 1 on the left arm was compatible with lichen purpuricus. Case 2 occurred in a linear arrangement on the right leg and had a history of aspirin use for chronic headache. We therefore suspected that medication had been an etiological or contributing factor.