Symmetric Groin Plaques in a Man With Diabetes

A 60-year-old man with type 2 diabetes mellitus and obesity presents to dermatology for evaluation of a flesh-colored pedunculated lesion on his right proximal thigh. During the examination, the clinician also notices bilateral groin plaques that the patient had not considered important.

The plaques are well-demarcated and brown-red with fine peripheral scale and central hypopigmentation along both inguinal folds. They are minimally symptomatic, with only occasional mild pruritus. He has no fever, no satellite pustules, and no involvement of the scrotum.

He reports chronic sweating and spends long hours working outdoors. He has tried an over-the-counter antifungal powder intermittently without clear improvement. The rest of the skin examination is unremarkable.