How long do lice live and how can they be eliminated? - briefly
Adult head lice survive about 30 days on a human scalp and up to 48 hours off‑host. Eradication requires meticulous wet combing with a fine‑toothed nit comb, optionally combined with an approved topical pediculicide.
How long do lice live and how can they be eliminated? - in detail
Lice survive on a human host for roughly one month. The life cycle begins with an egg (nit) that hatches in 7–10 days. Emerging nymphs undergo three molts over 5–7 days before reaching adulthood. Adult females live up to 30 days, laying 6–10 eggs per day; males survive slightly less, typically 2–3 weeks. Temperature and host availability influence longevity—higher ambient heat shortens the cycle, while cooler conditions extend it.
Elimination requires a multi‑step approach:
- Chemical pediculicides – dimethicone‑based lotions, permethrin, or pyrethrin formulations applied according to label instructions; repeat after 7–10 days to target newly hatched nymphs.
- Mechanical removal – fine‑toothed nit combs used on wet, conditioned hair; comb from scalp outward every 2–3 days for two weeks.
- Environmental sanitation – wash bedding, clothing, and personal items in hot water (≥60 °C) or seal in plastic bags for 2 weeks; vacuum carpets and upholstered furniture.
- Oral ivermectin – prescribed in resistant cases; dosage based on body weight, administered as a single dose or repeated after one week.
Preventive measures reinforce treatment success:
- Avoid sharing combs, hats, or headphones.
- Inspect children’s heads weekly, especially after school or camp attendance.
- Maintain hair length short enough to facilitate regular checks.
Combining chemical, mechanical, and environmental tactics yields the highest clearance rates, typically achieving complete eradication within three weeks when protocols are followed precisely.