Jock itch, also called tinea cruris, is a common skin infection that is
caused by a type of fungus called tinea. The fungus thrives in warm, moist
areas of the body and as a result, infection can affect the genitals, inner
thighs and buttocks. Infections occur more frequently in the summer or in warm,
Jock itch appears as a red, itchy rash that is often ring-shaped.
Read more about fungal infections of the skin.