Intralesional Betamethasone for Acne Scars: Mechanism, Use, and Alternatives

Intralesional corticosteroid injection (e.g., betamethasone dipropionate) is a recognized treatment for hypertrophic and keloid acne scars, not for atrophic (depressed) scars.

Mechanism

• Anti-inflammatory: reduces fibroblast proliferation, collagen synthesis, glycosaminoglycan production.
• Vasoconstriction: decreases blood flow to scar.
• Induces fibroblast apoptosis.

Indications

• Raised, firm, symptomatic (pruritic, painful) hypertrophic/keloid scars.
• Typically after failure of silicone gel/sheeting, pressure therapy.

Procedure

• Dilute betamethasone (e.g., 2.5–5 mg/mL) injected into scar at 3–4 week intervals.
• Max total dose limited to avoid systemic absorption.

Risks

• Skin atrophy, telangiectasia, hypopigmentation (especially in darker skin).
• Rare: adrenal suppression with large cumulative doses.

First-Line Alternatives

Silicone gel/sheets, fractional laser (CO2, erbium), microneedling RF, subcision, fillers (for atrophic scars), topical retinoids.

Always consult a board-certified dermatologist for scar assessment and tailored plan.