Intralesional Scalp Injection — SCE Dermatology MCQ

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ModerateInflammatory DermatosesIntralesional Scalp InjectionSCE Dermatology

A 40-year-old man has psoriasis with significant scalp disease. His dermatologist considers intralesional triamcinolone injection into thick scalp plaques. What concentration is typically used for scalp psoriasis?

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Correct answer: D — 5-10 mg/mL (diluted triamcinolone) — higher concentrations risk skin atrophy and alopecia on the scalp

For intralesional corticosteroid injection into scalp psoriasis plaques, triamcinolone acetonide is typically diluted to 5-10 mg/mL (diluted from the standard 40 mg/mL preparation with normal saline or lignocaine). Undiluted 40 mg/mL is too concentrated for the scalp — it risks significant dermal atrophy, subcutaneous fat atrophy, and scarring alopecia. Small volumes (0.05-0.1 mL per injection point) are injected intradermally into thick treatment-resistant plaques. Multiple injection points may be needed. Effects last 4-6 weeks. This technique is useful for focal resistant scalp plaques not responding to topical therapy and as a bridge to systemic treatment.

Reference: BAD 2020 Psoriasis; Dermatological Procedures