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Crusted Scabies — SCE Dermatology MCQ

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ModerateCutaneous InfectionCrusted ScabiesSCE Dermatology

A 55-year-old man presents with crusted scabies (Norwegian scabies). He is immunosuppressed following renal transplant. His skin shows widespread thick hyperkeratotic crusting on his hands and feet with millions of mites on scraping. What is the recommended treatment?

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Correct answer: C — Combined oral Ivermectin and topical Permethrin 5% with repeated treatments

Crusted (Norwegian) scabies requires combination therapy with BOTH oral Ivermectin (200 mcg/kg on days 1, 2, 8, 9, and 15) AND topical Permethrin 5% applied daily for 7 days then twice weekly until cure, due to the extremely high mite burden (millions vs. 5-15 mites in ordinary scabies). Topical treatment alone is insufficient because the thick crusts harbour mites inaccessible to topical agents. Environmental decontamination is critical. Crusted scabies is highly infectious. Barrier nursing is required. All contacts must be treated. BAD and NICE guidelines mandate aggressive combined therapy.

Reference: BAD 2017 Scabies Guidelines; NICE CKS