How many times should one wash the head to remove lice? - briefly
Three washes, each spaced «48 hours» apart, combined with an approved lice treatment, are generally advised. Washing alone does not guarantee eradication.
How many times should one wash the head to remove lice? - in detail
Washing the scalp alone does not guarantee complete elimination of head‑lice infestations. Effective control requires a combination of mechanical removal, chemical or physical treatment, and repeated actions timed to the parasite’s life cycle.
The first wash should be performed with a lice‑killing shampoo or detergent that contains an approved pediculicide (e.g., permethrin 1 % or dimethicone). After applying the product, the hair must be left wet for the manufacturer‑specified duration, typically 10 minutes, then rinsed thoroughly. Immediate combing with a fine‑toothed lice comb removes many live insects and nits that survive the chemical exposure.
Because newly hatched nits emerge approximately 7–10 days after the initial infestation, a second wash is necessary within this window. The recommended schedule is:
- Initial treatment and combing (day 0).
- Repeat wash and combing on day 7–9.
- Optional third wash on day 14 if any live lice are still detected.
Each wash should be followed by a meticulous combing session, inspecting the entire length of the hair for remaining nits. Environmental measures—washing bedding, clothing, and personal items in hot water (≥ 60 °C) or sealing them in a plastic bag for two weeks—support the eradication process but do not replace the need for repeated scalp washing.
In summary, two to three thorough washes, spaced one week apart and combined with systematic combing, provide the most reliable method for removing head lice and preventing re‑infestation.