Derm Cases · Dermatology / Paediatrics / Infectious Diseases / Public Health
OSCE — scalp itch and nits: pediculosis diagnosis and household management
An 8-minute OSCE station on head, body and pubic lice recognition, detection-combing diagnosis, dimeticone/permethrin two-dose regimens, contact treatment, school policy, body-louse vector red flags, and eyelash safeguarding issues.
On this page
Study tools
Target exams
NEET-PGINICETUSMLEPLABMRCP
Prompt
An 8-minute OSCE station on head, body and pubic lice recognition, detection-combing diagnosis, dimeticone/permethrin two-dose regimens, contact treatment, school policy, body-louse vector red flags, and eyelash safeguarding issues.
Brief (to candidate)
A 9-year-old girl has 2 weeks of scalp pruritus. Examination shows live lice on detection-combing and nits cemented close to the scalp on post-auricular and occipital hair. Two siblings itch; the school has asked if she must stay home. You have 8 minutes to confirm the diagnosis, treat the child and contacts, counsel environment and school policy, and mention other louse syndromes.
[6]Candidate instructions
- Confirm pediculosis capitis with detection-combing.
- Distinguish head, body, and pubic lice roles.
- Prescribe first-line pediculicide with two applications 7 days apart.
- Treat contacts and give environmental advice.
- State school return policy (no “no-nit” exclusion).
- Red flags: body-louse vectors, pubic lice/STI/safeguarding, eyelash lice.
Examiner checklist (mark each domain / 10)
| Domain | Key actions expected |
|---|---|
| Recognition | Live head lice (Pediculus humanus capitis) + eggs (nits) glued to hair shaft near scalp; itch post-auricular/occipital; diagnosis by detection-combing, not nits alone after treatment[1][2] |
| Species map | Head lice = hair-to-hair; body lice live in clothing seams (vector of typhus, trench fever, relapsing fever); pubic lice (Pthirus pubis) = STI association |
| First-line Rx | Dimeticone 4% lotion two applications 7 days apart (physical mode, preferred where available) or permethrin 1% / malathion 0.5% depending on resistance; second dose kills hatchlings[3][4] |
| Contacts | Detection-comb all household members; treat all positive cases the same day; avoid treating purely prophylactic without evidence of infestation where policy prefers case-based treatment |
| School & environment | No school exclusion after completed treatment application; “no-nit” policies not evidence-based; wash pillowcases/hats in hot water; do not over-focus on house fumigation |
| Resistance / failure | Check adherence and reinfestation first; if true failure, switch class (e.g. dimeticone ↔ malathion) or consider oral ivermectin 200–400 mcg/kg day 1 and 7–10 where licensed/appropriate |
| Red flags | Febrile homeless person with body lice → think vector-borne disease, decontaminate clothing, empirical doxycycline if indicated; pubic lice in child → safeguarding; eyelash lice → petrolatum occlusion, not pediculicides near eye |
Model key actions
- Confirm live head lice by combing; treat with dimeticone 4% (or permethrin 1%) on day 0 and day 7.[2][3]
- Comb and treat infested contacts; allow school return after treatment — reject no-nit exclusion.[4]
- Name body-louse public-health risks and eyelash special care if asked.
Common errors
- Treating nits alone without live lice confirmation (post-treatment empty shells).
- Single application without day-7 dose.
- Enforcing outdated school exclusion / no-nit policies.
- Applying permethrin near the eye for phthiriasis palpebrarum.
- Treating body lice only on skin while ignoring clothing seams.
References6ShowHide
- [1]Coates SJ, Thomas C, Chosidow O, et al. Ectoparasites: Pediculosis and tungiasis. Journal of the American Academy of Dermatology, 2020.PMID 31306729
- [2]Meister L, Ochsendorf F. Head Lice. Deutsches Arzteblatt international, 2016.PMID 27974145
- [3]Burgess IF, Silverston P. Head lice. BMJ clinical evidence, 2015.PMID 25587918
- [4]Gunning K, Kiraly B, Pippitt K. Lice and Scabies: Treatment Update. American Family Physician, 2019.PMID 31083883
- [5]Meinking TL. Clinical update on resistance and treatment of Pediculosis capitis Am J Manag Care, 2004.PMID 15515630
- [6]Lamassiaude N, Toubate B, Neveu C, et al. The molecular targets of ivermectin and lotilaner in the human louse Pediculus humanus humanus: New prospects for the treatment of pediculosis PLoS Pathog, 2021.PMID 33600484