Unilateral Schamberg disease in a 14-year-old Japanese boy.

We report a 14-year-old Japanese boy who has had asymptomatic, multiple, reddish-brown macules and petechiae distributed segmentally only in the right lower extremity for the last 6 months. Histological examination showed a perivascular lymphohistiocytic infiltrate in the papillary dermis, extravasation of red blood cells, and hemosiderin deposition. Treatment with tranilast and topical corticosteroid was dramatically effective. Although the histological findings were compatible with those of Schamberg disease, this case was unusual because the patient was very young and only one extremity was affected.