What is an effective treatment for lice? - briefly
A 1 % permethrin lotion applied to dry hair for 10 minutes, rinsed, and repeated after 7–10 days eradicates the majority of infestations. Oral ivermectin (200 µg/kg) given as a single dose, with a second dose a week later if necessary, provides an equally effective alternative.
What is an effective treatment for lice? - in detail
Effective lice eradication requires a multi‑step approach that combines appropriate topical agents, mechanical removal, and environmental measures.
First‑line topical products contain synthetic pyrethroids (e.g., 1 % permethrin) or dimethicone. Permethrin works by disrupting nerve function in the insect; a single 10‑minute application to dry hair followed by thorough rinsing eliminates most live insects. Dimethicone, a silicone‑based oil, suffocates lice without neurotoxic action; it is applied to damp hair, left for 8–10 hours, then washed out. Both agents should be reapplied after 7–10 days to target newly hatched nymphs, as eggs are resistant to chemical action.
When resistance to pyrethroids is documented, alternatives such as malathion (0.5 % lotion) or spinosad (0.9 % suspension) are recommended. Malathion requires a 30‑minute exposure on dry hair and is contraindicated for children under 2 years. Spinosad, approved for children 6 months and older, is left on the scalp for 10 minutes before washing.
Mechanical removal supplements chemical treatment. Wet combing with a fine‑toothed lice comb, performed on shampoo‑wetted hair, extracts live insects and viable eggs. Repeating the combing every 2–3 days for two weeks yields high clearance rates, especially in cases where chemicals are unsuitable (e.g., allergy, pregnancy).
Environmental control limits re‑infestation. Items that contact the scalp—pillowcases, hats, hairbrushes—should be washed at ≥ 60 °C or sealed in airtight bags for 2 weeks. Non‑washable objects may be vacuumed or exposed to direct sunlight for several hours. Regular inspection of household members identifies secondary cases early.
Safety considerations dictate precise dosing and adherence to age restrictions listed on product labels. Over‑application increases the risk of skin irritation and systemic absorption. Parents should avoid using multiple concurrent pediculicides, as this does not improve efficacy and may amplify adverse effects.
In practice, a typical regimen includes:
- Apply permethrin 1 % or dimethicone according to instructions.
- After 7–10 days, repeat the application.
- Perform wet combing every 2 days for 14 days.
- Wash or isolate personal items for at least 14 days.
- Monitor all contacts; treat any additional infestations promptly.
Combining a proven topical agent with systematic combing and thorough environmental hygiene delivers the most reliable outcome for lice removal.