Betamethasone and Gentamicin is a combination of two drugs used to treat various skin infections. Betamethasone is a corticosteroid that reduces inflammation and itching, while Gentamicin is an antibiotic that fights bacterial infections. The combination of these drugs is used to treat bacterial skin infections that are also accompanied by inflammation or itching, such as eczema or psoriasis. The medication is usually applied topically in the form of a cream, lotion or ointment, and should be used only as directed by a healthcare provider.