Jock itch (tinea cruris) is a fungal infection that affects the skin of your genitals, inner thighs and buttocks. Jock itch causes an itchy, red, often ring-shaped rash in these warm, moist areas of your body.
Jock itch gets its name because it is common in people who sweat a lot, as do athletes. It also is more likely to occur in people who are overweight.
Although often uncomfortable and bothersome, jock itch usually isn't serious. Keeping your groin area clean and dry and applying topical antifungal medications usually are sufficient to treat jock itch.