Focal pigmentation of an eroded erythematous inguinal plaque in an older man

Abstract

A 73-year-old male presented with several years of a painful rash in the left inguinal fold which slowly progressed to a focally eroded pink plaque with central hyperpigmentation (Fig 1), refractory to outside treatment with topical econazole, hydrocortisone 1% cream, and oral cephalexin. He denied gastrointestinal and genitourinary symptoms. Examination was negative for palpable inguinal lymphadenopathy. Histology of the excised lesion with hematoxylin and eosin (H&E) as well as immunostaining was performed (Fig 2 and 3).