Ringworm is a fungal skin infection. (It is not due to a worm as its name implies!) There are many types of fungal germs (fungi) and some can infect the skin, nails, and hair. This leaflet just deals with ringworm of the skin (sometimes called tinea corporis). Other leaflets deal with fungal infections of the scalp (scalp ringworm), foot (athlete's foot), groin (tinea cruris), and nails.