Derm Dx: Red, itchy groin rash

An obese man, aged 56 years, presents with a groin rash that has been present for several weeks. He states that it is very itchy and uncomfortable and that it seems to have worsened following use of hydrocortisone. The patient’s medical history is significant for type 2 diabetes controlled with metformin.

Examination reveals a red eruption of the intertriginous folds. ...