Diagnostic Implications Betamethasone is a corticosteroid with anti-inflammatory and immunosuppressive abilities, used especially where water retention is undesirable. It is applied as a topical cream, ointment, lotion or gel to treat itching (e.g. from eczema). Corticosteroid used to stimulate fetal lung maturation and to decrease the incidence and mortality from intracranial hemorrhage in premature infants