Tinea cruris (TC), also known as jock itch, is a common type of contagious, superficial fungal infection of the groin and buttocks region, which occurs predominantly but not exclusively in men and in hot-humid climates.
Typically, over the upper inner thighs, there is an intensely itchy red raised rash with a scaly well-defined curved border. It is often associated with athlete's foot and fungal nail infections, excessive sweating, and sharing of infected towels or sports clothing. It is uncommon in children.