n.
Superficial skin changes caused by certain fungi (see fungus ) that live on the skin, feeding on keratin .
Skin responses vary from slight scaling to blistering and marked disruption of the keratin layer (depending on body area and type of fungus), usually in a ring shape. It includes athlete's foot , jock itch, and fungal infections of the body, hands, nails, and scalp. While the last is very contagious, spread of other types depends on susceptibility and predisposing factors (e.g., excessive perspiration). Ringworm is treated with medications applied to the skin or taken orally.