Ringworm of the Skin Is this topic for you? This topic is about
ringworm of the skin, groin, or hands. For information about
other fungal infections, see the topics Athlete's Foot, Diaper
Rash, Fungal Nail Infections, and Ringworm of the Scalp or
Beard. What is ringworm of the skin? Ringworm of the skin is an
infection caused by a fungus. Jock itch is a form of ringworm
that causes an itchy rash on the skin of your groin area. It is
much more common in men than in women. Jock itch may be caused
by the spread of athlete's foot fungus to the groin. What causes
ringworm? Ringworm is not caused by a worm. It is caused by a
fungus. The kinds of fungi (plural of fungus) that cause
ringworm live and spread on the top layer of the skin and on the
hair. They grow best in warm, moist areas, such as locker rooms
and swimming pools, and in skin folds. Ringworm is contagious.
It spreads when you have skin-to-skin contact with a person or
animal that has it. It can also spread when you share things
like towels, clothing, o