Betamethasone cream is used to treat skin disorders such as eczema, dermatitis, allergies, and rash. Betamethasone relieves the swelling, itching, and redness that might accompany these illnesses. It is a corticosteroid of medium strength. Betamethasone topical comes in cream, gel, ointment, lotion, foam, and spray forms. Common betamethasone side effects include itching, redness, burning, stinging, or blistering of the treated area, skin bruising or a glossy look, and redness or crusting around your hair follicles.