How can head lice be treated? - briefly
Effective management involves applying an over‑the‑counter pediculicide (e.g., permethrin or pyrethrin) to dry hair for the specified time, then meticulously combing with a fine‑toothed lice comb to eliminate nits. If resistance is suspected, prescription treatments such as malathion or ivermectin, plus a repeat application after 7–10 days, are recommended.
How can head lice be treated? - in detail
Effective elimination of head‑lice infestations relies on a combination of topical agents, mechanical removal, and environmental control. Successful management requires correct product selection, thorough application, and repeat treatment according to the life cycle of the parasite.
- Over‑the‑counter insecticides: Permethrin 1 % lotion and pyrethrin‑piperonyl‑butoxide shampoos are applied to dry hair, left for the recommended time (usually 10 minutes), then rinsed. Both target the nervous system of lice but may be less effective where resistance is documented.
- Prescription options: Malathion 0.5 % oil, benzyl alcohol 5 % lotion, spinosad 0.9 % suspension, and ivermectin 0.5 % lotion provide alternatives for resistant populations. Each requires strict adherence to dosing intervals; for example, malathion is left on hair for 8–12 hours before washing.
- Non‑chemical methods: Wet combing with a fine‑toothed metal comb removes live insects and nits when hair is saturated with conditioner and combed from scalp to tip in 15‑minute sessions, repeated every 2–3 days for two weeks. Silicone‑based lotions (e.g., dimethicone) coat lice, causing immobilization without neurotoxic action. Heat devices that raise hair temperature to 50 °C for 10 minutes achieve mortality without chemicals.
Environmental measures complement direct treatment. Wash bedding, hats, and clothing used within the previous 48 hours in hot water (≥60 °C) or seal items in plastic bags for two weeks to starve surviving stages. Vacuum carpets and upholstered furniture; discard or clean hair‑brushes and combs in boiling water.
A second application of the chosen topical agent is recommended 7–10 days after the initial dose to eradicate newly hatched nymphs before they mature. Post‑treatment inspection should occur 24 hours after each application, confirming the absence of live lice and viable nits. Persistent detection after two cycles warrants medical evaluation for alternative therapies or underlying resistance.