Synopsis
Confirm lice by finding live insects, distinguish head, body and pubic infestation from bite hypersensitivity, coordinate contact and environmental measures, and identify anaphylaxis, infection, tick and safeguarding concerns.
- Diagnose head lice only by finding a live moving louse with wet detection combing; nits alone may be empty or non-viable.
- Check household members and treat those with live lice on the same day; routine treatment of uninfested contacts is unnecessary.
- Use wet combing on days 1, 5, 9 and 13 with a check on day 17, or a licensed physical insecticide exactly as directed.
- Many dimeticone products require a second application after seven days; resistance is less relevant to a physical coating mechanism.
- Pubic lice warrants treatment of recent sexual contacts and an STI screen; eyelash involvement needs eye-safe specialist advice.
- Body lice control depends on laundering or replacing infested clothing and bedding plus access to washing and social support.
- Bite reactions are managed with source control, cold compresses, oral non-sedating antihistamine and appropriate topical anti-inflammatory care, not routine antibiotics.
- Treat anaphylaxis with intramuscular adrenaline and assess expanding erythema, fever or necrosis separately from a large local allergic reaction.
Key red flags
Airway, breathing or circulation compromise after a bite, expanding severe infection, fever with travel or tick exposure, eyelash lice with ocular injury, unexplained genital lice in a child or widespread infestation in a vulnerable person requires urgent assessment.
Sudden airway swelling, wheeze, hypoxia, hypotension or collapse after a bite or sting requires intramuscular adrenaline.
Investigation priorities
Confirm active head lice before treatment.
Management branches
A live louse is found by detection combing.
- Check household members and treat all confirmed cases on the same day.
- Use scheduled wet combing or a licensed dimeticone product, repeating at seven days when its instructions require it.
- Recheck for live lice after the completed regimen and distinguish reinfestation, under-application and nits from failure.
Key medicines
Dimeticone 4% lotionApply to dry hair and scalp until fully covered, leave for the product-specified period and repeat after seven days when directed.Follow the exact licensed product because contact times differ, avoid flames and heat while hair is treated, protect eyes and do not use incomplete leftover quantities.
Cetirizine 10 mg tabletsAdults and people aged 12 years or older take 10 mg orally once daily when bite-related itch warrants an antihistamine.Somnolence can occur; consider driving, alcohol and renal adjustment, and do not substitute it for adrenaline in anaphylaxis.