How long does it take for lice to be cleared from a child's head? - briefly
With an approved pediculicide applied according to instructions and a repeat treatment after 7–10 days, most infestations are eliminated within 10–14 days; thorough combing and cleaning of personal items further prevents recurrence.
How long does it take for lice to be cleared from a child's head? - in detail
Head lice (Pediculus humanus capitis) complete their life cycle in roughly 7‑10 days: an egg hatches in about 9 days, nymphs mature in 5‑6 days, and adult females begin laying eggs after another 7‑10 days. Because eggs (nits) are resistant to most insecticides, treatment must address both live lice and newly hatched nymphs.
- Apply a pediculicide (permethrin 1 %, pyrethrin + piperonyl‑butoxide, or dimethicone) according to the product label, typically a single dose followed by a repeat application 7‑10 days later to eliminate lice that emerged from surviving nits.
- Perform wet combing with a fine‑toothed nit comb at least once daily for 10 days. Each session should begin with a conditioner to loosen nits, then run the comb from scalp to hair tip, removing all visible eggs and lice before rinsing and repeating.
- Wash all recently used clothing, bedding, and towels in hot water (≥ 54 °C) or seal them in a plastic bag for 48 hours if washing is unavailable. Vacuum carpets and upholstered furniture to reduce the risk of reinfestation.
Effectiveness is usually confirmed within 2‑3 weeks. A follow‑up inspection on day 14 after the second chemical dose or after the final combing session should show no live lice and no viable nits. If any live insects are observed, repeat the treatment cycle and reassess environmental controls. Persistent infestations may indicate resistance; in such cases, switch to a non‑chemical option (e.g., dimethicone) or seek professional medical advice.