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Psoriasis — SCE Dermatology MCQ

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EasyInflammatory DermatosesPsoriasisSCE Dermatology

A 40-year-old woman has chronic scalp psoriasis refractory to Betamethasone scalp application. She finds topical preparations difficult to apply due to thick scale. What practical step should be recommended before applying topical treatment?

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Correct answer: E — Descale with coconut oil or salicylic acid preparation overnight before applying active treatment

Thick adherent scale on the scalp forms a barrier to topical drug penetration, reducing efficacy. Descaling with a keratolytic agent (2% salicylic acid in coconut oil or Cocois ointment — containing coal tar, salicylic acid, and coconut oil) applied under occlusion overnight and washed out in the morning removes scale and allows subsequent topical corticosteroid to penetrate effectively. This two-step approach (descale → treat) significantly improves outcomes. Coal tar shampoo can also help. Systemic therapy should only be considered after topical treatment has been properly optimised, including descaling.

Reference: BAD 2020 Psoriasis Guidelines; NICE CG153