Clotrimazole and betamethasone topical combination is used to treat fungus infections. Clotrimazole works by killing the fungus or preventing its growth. Betamethasone, a corticosteroid (cortisone-like medicine or steroid), is used to help relieve redness, swelling, itching, and other discomfort of fungus infections.Clotrimazole and betamethasone topical cream or lotion is applied to the skin to treat: 1  Ringworm of the foot (tinea pedis; athlete's foot);2  Ringworm of the groin (tinea cruris; jock itch); and. 3  Ringworm of the body (tinea corporis).lotrimazole works by killing the fungus or preventing its growth. Betamethasone, a corticosteroid (cortisone-like medicine or steroid), is used to help relieve redness, swelling, itching, and other discomfort of fungus infections.