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 itch

Jock itch tends to cause itchy or burning sensation in the groin, thigh skin folds, or the anus; the rash appears as raised red plaques that may blister, ooze, or advance down the inner thigh. As the rash advances, it often forms a central area of clearing with advancing borders resembing a ring (hence the name ringworm). Tinea cruris is diagnosed by scraping some of the affected skin onto a glass slide, applying potassium hydroxide (KOH) to dissolve keratin from the skin cells to release the hyphae, heating the slide, and looking under the microscope for hyphae. A sample may also be sent to a lab for a mycotic culture (where the fungus is grown in Sabouraud’s agar).^[2] This article will help you treat and cure this fungal infection.