Athlete's foot, also known as ringworm of the foot, or tinea pedis, is a fungal infection of the skin that causes scaling, flaking and itch of affected areas. It is caused by fungi in the genus Trichophyton. The fungus genus Trichophyton is characterized by the development of both smooth walled macro and microconidia. Trichophyton rubrum is a fungus that is the most common cause of athlete's foot, jock itch and ringworm.