Ringworm is a fungal infection of the skin that is characterized by an often itchy, reddish to brownish ring-shaped rash. Ringworm on the body is also known as tinea corporis and is related to other fungal infections such as ringworm of the scalp, athlete's foot and jock itch.Ad.ingworm has nothing to do with a worm, but is actually a fungal infection. The common symptoms of ringworm include: 1  A rash that is itchy, red, scaly, and raised, and which may blister or ooze. 2  A rash that has clearly defined edges.