Inguinal Erythrasma

A 38-year-old man presented with a 9-month history of mildly itchy groin rash misdiagnosed as tinea cruris. Examination revealed well-defined, reddish-brown plaques in the inguinal folds without scaling or satellite lesions. Fungal testing was negative. Wood’s lamp illumination revealed coral-red fluorescence, and bacterial culture confirmed Corynebacterium minutissimum, diagnosing inguinal erythrasma, a superficial skin infection often mistaken for fungal dermatoses. Distinction is aided by its hue, lack of scale, and fluorescent appearance under Wood’s lamp due to porphyrins. The condition resolved after topical mupirocin and oral erythromycin treatment.

A 38-year-old man presented with a 9-month history of mildly itchy groin rash misdiagnosed as tinea cruris. Examination revealed well-defined, reddish-brown plaques in the inguinal folds without scaling or satellite lesions. Fungal testing was negative. Wood’s lamp illumination revealed coral-red fluorescence, and bacterial culture confirmed Corynebacterium minutissimum, diagnosing inguinal erythrasma, a superficial skin infection often mistaken for fungal dermatoses. Distinction is aided by its hue, lack of scale, and fluorescent appearance under Wood’s lamp due to porphyrins. The condition resolved after topical mupirocin and oral erythromycin treatment.