How can lice be washed? - briefly
Treat infestations by washing hair with a medicated shampoo at 37‑38 °C, then rinsing thoroughly and combing with a fine-toothed lice comb to remove insects and nits. Repeat the process after 7‑10 days to eliminate any newly hatched lice.
How can lice be washed? - in detail
Effective removal of head‑lice through washing requires a combination of mechanical action, appropriate temperature, and, when necessary, chemical adjuncts.
First, select a shampoo that contains a proven pediculicide, such as permethrin 1% or pyrethrin 0.5 %. Apply the product to thoroughly saturated hair, ensuring complete coverage of the scalp and each strand. Leave the solution on for the manufacturer‑specified contact time, typically 10 minutes, to allow the active ingredient to penetrate the insect exoskeleton.
Second, rinse with water at a temperature of at least 40 °C (104 °F). Hot water softens the hair cuticle, loosens the glue that secures nits to strands, and enhances the lethal effect of the pesticide. Follow the rinse with a cool‑water flush to close the cuticle and reduce scalp irritation.
Third, employ a fine‑toothed lice comb immediately after rinsing. Starting at the scalp, draw the comb through the hair in a systematic manner, moving outward strand by strand. After each pass, wipe the comb on a paper towel or rinse it under running water to remove captured insects. Repeat the combing process at least three times over a 24‑hour period, as newly hatched nymphs may emerge after the initial treatment.
Fourth, launder all personal items that have contacted the head. Wash clothing, pillowcases, and towels in hot water (≥ 60 °C / 140 °F) and tumble‑dry on high heat for a minimum of 30 minutes. For non‑washable items, seal them in a plastic bag for two weeks to starve any surviving lice.
Fifth, consider supplemental measures if resistance to standard pediculicides is suspected. Options include:
- Dimethicone‑based lotions that suffocate insects without neurotoxic action.
- Spinosad 1% shampoo, effective against resistant strains.
- Manual removal without chemicals, relying solely on combing after thorough wetting with hot water.
Finally, monitor the scalp daily for at least two weeks. Inspect hair under bright light, focusing on behind ears and the nape, to detect any residual nits. A repeat treatment may be necessary after 7–10 days to eradicate any survivors that escaped the initial wash.
Adhering to this protocol maximizes the likelihood of complete eradication while minimizing reinfestation risk.