Betamethasone

Key facts

• Betamethasone (in creams and ointments such as Betnovate and Diprosone, and combined with clotrimazole or fusidic acid in some products) is a corticosteroid, not an antifungal or antibiotic; it calms the immune reactions that cause inflammation in the skin.
• Apply a thin layer exactly as directed, usually once or twice a day, for the shortest course that controls your symptoms.
• Using it for weeks at a time, on the face, in skin folds, or under a dressing thins the skin and lets enough drug into the bloodstream to suppress your own cortisol production.
• Seek urgent care if a treated area gets more red, swollen or painful instead of better, or if you develop hives, facial swelling or difficulty breathing.

What betamethasone treats

Betamethasone treats inflammatory skin conditions: eczema, psoriasis, allergic and contact dermatitis, and reactions to insect bites. It reduces the redness, swelling and itching these cause. Some products combine it with an antifungal (clotrimazole) or antibiotic (fusidic acid) for infected skin that is also markedly inflamed; in those, the partner ingredient treats the infection while betamethasone calms the surrounding inflammation.

How betamethasone works

Betamethasone passes into the skin and binds glucocorticoid receptors inside cells, switching off the genes that produce inflammatory chemicals. This narrows small blood vessels, quiets immune cell activity, and reduces the swelling, redness and itching inflammation causes. Its effect is mostly local to the area treated, but enough can cross into the bloodstream, particularly through broken or thin skin, to act on the rest of the body.

Before you take it

• Do not use it on skin with an active untreated fungal, bacterial or viral infection, including cold sores or chickenpox, unless a suitable antimicrobial is being used alongside it.
• Avoid the eyes and mucous membranes, and do not use it on the face, eyelids or groin for extended periods without medical advice.
• Tell your prescriber if you are pregnant or breastfeeding, have diabetes, or have a weakened immune system.
• Do not cover treated skin with an airtight dressing, and take care with infants in occlusive nappies, since both increase how much is absorbed.

Side effects

Common effects are mild burning or stinging on application, dryness, and small acne-like bumps.

Stop and seek medical care for:

• Skin that thins, bruises easily, or develops stretch marks with continued use.
• An infection that seems to be getting worse rather than better.
• Signs of an allergic reaction: hives, facial or throat swelling, or difficulty breathing.

Safety essentials

• Use the lowest strength and shortest course that controls your symptoms. Heavy use over weeks, over large areas, or under a dressing thins the skin and can suppress your own cortisol production; stopping suddenly after prolonged heavy use can trigger a rebound flare.
• If a combination product is prescribed for infected skin, do not exceed the course length ordered, and see a clinician if it is not improving.
• Never use it alone on an unassessed infection, and avoid prolonged use on the face, eyelids or skin folds.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.