What can be used to kill lice on the head? - briefly
Permethrin‑ or pyrethrin‑based OTC pediculicides, prescription ivermectin or malathion, and dimethicone lotion are proven to eradicate head lice. A fine‑toothed nit comb used after treatment removes remaining nits.
What can be used to kill lice on the head? - in detail
Effective eradication of head‑lice infestations relies on a combination of pharmacologic agents, mechanical removal, and environmental measures.
Over‑the‑counter pediculicides are the first line of treatment. Common products contain:
- 1 % permethrin or pyrethrin‑based sprays and lotions
- 0.5 % malathion cream
- 4 % benzyl‑alcohol lotion
- 0.5 % ivermectin lotion
These preparations are applied to dry hair, left for the recommended period (usually 10 minutes), then rinsed. Resistance to permethrin has been reported; in such cases, an alternative agent should be selected.
Prescription options include higher‑strength formulations and oral therapy:
- 1 % spinosad lotion, applied for 10 minutes
- 0.2 % ivermectin lotion, applied for 10 minutes
- Single oral dose of ivermectin (200 µg/kg) for severe or refractory cases
All chemical treatments require a second application 7–10 days after the first to kill newly hatched nymphs.
Mechanical removal employs a fine‑toothed nit comb. The procedure involves:
- Wetting hair with a conditioner to reduce slip
- Running the comb from scalp to tip in 1‑inch sections
- Repeating the process every 2–3 days for a week
Consistent combing eliminates live lice and detached nymphs that chemicals may miss.
Natural or physical agents provide non‑chemical alternatives:
- Dimethicone‑based products create a coating that suffocates lice; efficacy comparable to permethrin when applied correctly
- Tea‑tree oil (5 % solution) shows limited activity; not recommended as sole therapy
- Petroleum jelly applied to the scalp for several hours can immobilize lice but is difficult to rinse
Evidence for these methods is less robust than for FDA‑approved pediculicides.
Environmental control reduces re‑infestation risk. Recommended actions:
- Wash clothing, bedding, and towels in hot water (≥ 54 °C) and dry on high heat
- Seal non‑washable items in plastic bags for 2 weeks
- Vacuum carpets, upholstery, and car seats
Integration of chemical treatment, thorough combing, and strict environmental hygiene yields the highest success rate. Follow product instructions precisely, repeat the treatment cycle as indicated, and monitor for residual lice for at least two weeks after the final application.