Uses: this medication is used to treat a variety of fungal skin infections such as ringworm, athlete s foot, and jock itch. this medication is also used to treat a skin condition known as pityriasis (tinea versicolor), a fungal infection that causes a lightening or darkening of the skin of the neck, chest, arms, or legs. butenafine is an antifungal that works by preventing the growth of fungus.do not use this medication for the treatment of fungal nail infections.