Macroconidia of the dermatophytic fungus Epidermophyton floccosum, a fungus that commonly causes jock itch.Jock itch, also known as crotch itch, gym itch, eczema marginatum[1], ringworm of the groin, or tinea cruris, is a fungal infection of the groin caused by dermatophytes (Microsporum, Trichophyton, and Epidermophyton). It is more common in males, and is predisposed by increased moisture (as in hot, humid summer times), which promotes growth of the fungus ... Tinea cruris, or jock itchJock