How to treat lice in people? - briefly
Effective treatment uses a pediculicide shampoo or lotion applied to dry hair for the recommended time, then removes remaining nits with a fine‑toothed comb. A second application 7–10 days later eliminates any newly hatched lice.
How to treat lice in people? - in detail
Lice infestations in humans require accurate diagnosis, prompt pharmacologic action, and thorough environmental control.
First, confirm the presence of live insects or viable eggs by inspecting the scalp, body hair, or pubic region with a fine-tooth comb under bright light. Adult lice are approximately 2–4 mm, grayish‑brown, and move quickly; nits are oval, firmly attached to hair shafts near the scalp.
Pharmacologic options
- Permethrin 1 % lotion: Apply to dry hair, leave for 10 minutes, then rinse. Effective against head lice; repeat after 7–10 days to eliminate newly hatched insects.
- Pyrethrin with piperonyl‑butoxide: Similar application; useful when resistance to permethrin is suspected.
- Malathion 0.5 % lotion: Apply to dry hair, leave for 8–12 hours, then wash. Reserved for resistant cases; avoid use in children under 6 months.
- Benzyl alcohol 5 % lotion: Works by asphyxiating lice; apply for 10 minutes, then rinse. Not ovicidal; a second treatment after 7 days is required.
- Ivermectin 0.5 % lotion: Single application, leave for 10 minutes, then rinse. Effective for both head and pubic lice; safe for children over 15 kg.
- Spinosad 0.9 % suspension: Apply to dry hair, leave for 10 minutes, then rinse. Provides ovicidal activity, reducing need for a second application.
Mechanical removal
- Use a fine-tooth nit comb on wet, conditioned hair. Comb from scalp to tip, cleaning the comb after each pass. Perform daily for at least 10 days to remove residual nits.
Environmental measures
- Wash clothing, bedding, and towels used within the previous 48 hours in hot water (≥ 60 °C) and dry on high heat.
- Seal non‑washable items in a sealed plastic bag for two weeks.
- Vacuum carpets and upholstered furniture to collect stray insects.
Follow‑up
- Re‑examine after 7–10 days. Absence of live lice confirms successful treatment; any remaining nits should be removed manually.
- In cases of persistent infestation, consider resistance testing or switch to a different active ingredient.
Special populations
- Infants under 2 months: Use only physical removal methods; avoid chemical pediculicides.
- Pregnant or lactating women: Prefer permethrin or physical removal; consult a healthcare provider before using prescription agents.
- Allergic individuals: Conduct a patch test on a small skin area before full application.
Combining a proven topical agent with diligent nit removal and proper laundering eliminates the infestation and prevents reinfestation.