Ketoconazole cream is used to treat tinea corporis (ringworm; fungal skin infection that causes a red scaly rash on different parts of the body), tinea cruris (jock itch; fungal infection of the skin in the groin or buttocks), tinea pedis (athlete’s foot; fungal infection of the skin on the feet and between the toes), tinea versicolor (fungal infection of the skin that causes brown or light colored spots on the chest, back, arms, legs, or neck), and yeast infections of the skin. Prescription ketoconazole shampoo is used to treat tinea versicolor. Over-the-counter ketoconazole shampoo is used to control flaking, scaling, and itching of the scalp caused by dandruff. Ketoconazole is in a class of antifungal medications called imidazoles.