Derm Cases · Dermatology / Infectious Diseases / Public Health
OSCE — nocturnal itch and burrows: scabies diagnosis and household treatment
An 8-minute OSCE station on classical and crusted scabies recognition, IACS diagnostic approach, permethrin/ivermectin regimens, simultaneous contact treatment, environmental measures, and post-scabetic itch counselling.
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Study tools
Target exams
NEET-PGINICETUSMLEPLABMRCP
Prompt
An 8-minute OSCE station on classical and crusted scabies recognition, IACS diagnostic approach, permethrin/ivermectin regimens, simultaneous contact treatment, environmental measures, and post-scabetic itch counselling.
Brief (to candidate)
A 28-year-old man in a shared hostel has 3 weeks of intense nocturnal pruritus. Examination shows excoriated papules and burrows in finger webs, flexor wrists and genital skin; a roommate has similar itch. You have 8 minutes to confirm the diagnosis, treat the patient and contacts, and counsel on environment and post-treatment itch.
[4]Candidate instructions
- Recognise classical scabies distribution and burrows; mention crusted scabies risk groups.
- Apply a practical diagnostic approach (clinical ± microscopy/dermoscopy).
- Prescribe first-line treatment with correct application technique and second dose timing.
- Treat all close contacts simultaneously even if asymptomatic.
- Explain laundry/environment measures and post-scabetic itch.
- Safety-net treatment failure and institutional outbreak scenarios.
Examiner checklist (mark each domain / 10)
| Domain | Key actions expected |
|---|---|
| Recognition | Nocturnal itch; burrows/papules in finger webs, wrists, genitalia, axillae, belt line; head usually spared in classic adult disease[1][4] |
| Variants | Mentions crusted (Norwegian) scabies in immunocompromised/elderly institutional settings — high mite load, may itch less, highly contagious |
| Diagnosis | Clinical diagnosis often sufficient; IACS criteria concept; optional burrow scrapings / dermoscopy (delta-wing jet sign) when available[3] |
| Treatment | Permethrin 5% cream neck-to-toes (include web spaces, genitals, under nails); leave 8–12 h; repeat in 7 days; or oral ivermectin two-dose regimen when indicated (not for young infants/pregnancy per local rules)[2] |
| Contacts & environment | Treat all household/sexual/close contacts same day; wash bedding/clothes ≥50°C or bag 3–7 days; avoid only treating the index case |
| Post-scabetic itch | Itch may persist 2–4 weeks after mite kill — not automatic failure; use emollients/antihistamines/short topical steroid; re-treat if new burrows after adequate dual therapy |
| Communication | Stigma-sensitive explanation; return if extensive crusting, secondary infection, or household reinfestation |
Model key actions
- Diagnose classical scabies from nocturnal itch + burrow distribution + contact history.[1][3]
- Permethrin two applications one week apart + simultaneous contact treatment + laundry measures.[2]
- Counsel post-scabetic itch to prevent unnecessary panic re-treatment cycles.
Common errors
- Treating index case only.
- Single application without week-2 dose.
- Missing web spaces/genitals in application instructions.
- Calling residual itch at day 10 treatment failure without new burrows.
- Missing crusted scabies in nursing-home/immunosuppressed contexts (needs intensified multi-dose + isolation).
References4ShowHide
- [1]Fernando DD, Mounsey KE, Bernigaud C, et al. Scabies. Nature Reviews Disease Primers, 2024.PMID 39362885
- [2]Salavastru CM, Chosidow O, Boffa MJ, et al. European guideline for the management of scabies. Journal of the European Academy of Dermatology and Venereology, 2017.PMID 28639722
- [3]Engelman D, Yoshizumi J, Hay RJ, et al. The 2020 International Alliance for the Control of Scabies Consensus Criteria for the Diagnosis of Scabies. British Journal of Dermatology, 2020.PMID 32034956
- [4]Sunderkötter C, Wohlrab J, Hamm H. Scabies: Epidemiology, Diagnosis, and Treatment. Deutsches Arzteblatt International, 2021.PMID 34615594