Betamethasone is a steroid medication. It is used for a number of diseases including rheumatic disorders such as rheumatoid arthritis and systemic lupus erythematosus, skin diseases such as dermatitis and psoriasis, allergic conditions such as asthma and angioedema, preterm labor to speed the development of the baby's lungs, Crohn's disease, cancers such as leukemia, and along with fludrocortisone for adrenocortical insufficiency, among others. It can be taken by mouth, injected into a muscle, or applied as a cream. When given by injection, anti-inflammatory effects begin in around two hours and last for seven days.
Betamethasone is available in a number of different preparations. It is likely you will be prescribed a cream if the affected areas of your skin are moist or weeping, an ointment if your skin is dry, or a lotion for larger or hairy areas of skin. It is also available as an application for the scalp. Betamethasone is not generally suitable for children, although short courses of up to two weeks may occasionally be prescribed for a child by a skin specialist doctor.