Antifungal drugs are of two kinds, systemic and topical. Systemic antifungal drugs are medicines taken by mouth or by injection to treat infections caused by a fungus. Topical antifungal drugs are medicines applied to the skin to treat skin infections caused by a fungus.

A fungus is a one-celled form of life. Unlike a plant, which makes its own food, or an animal, which eats plants or other animals, a fungus survives by invading and living off other living things. Because fungi thrive in moist, dark places, fungal infections are especially likely to be found in the mouth, armpits, groin, and genital areas. But they can also occur on the scalp, neck, trunk, and other parts of the body. Common fungal infections include athlete's foot, jock itch, candidiasis (also called thrush or yeast infection), and ringworm, which is not caused by a worm, but by a...