What works against lice and nits? - briefly
Over‑the‑counter pediculicides such as 1 % permethrin or pyrethrin, applied together with a fine‑toothed nit comb after a conditioning treatment, eradicate most infestations. For resistant cases, prescription options like ivermectin lotion or spinosad 0.9 % provide proven efficacy.
What works against lice and nits? - in detail
Effective eradication of head lice and their eggs relies on a combination of chemical, physical, and environmental strategies.
First‑line chemical agents include permethrin 1 % lotion and pyrethrin‑based products, which disrupt the nervous system of the insects. In regions where resistance to these compounds is documented, alternatives such as malathrin (0.5 %–1 % concentration), spinosad (0.9 % suspension), or ivermectin (0.5 % lotion) provide reliable knock‑down of adult lice and early‑stage nits. All topical insecticides must be applied according to the manufacturer’s instructions, left on the scalp for the recommended duration, and rinsed thoroughly.
Physical removal complements chemical treatment. Fine‑toothed nit combs, with teeth spaced 0.2 mm apart, extract live lice and visible eggs when used on wet, conditioned hair. Repeating the combing process every 2–3 days for at least three sessions eliminates newly hatched nits that escaped the initial application.
Suffocation products, primarily dimethicone‑based liquids, coat the exoskeleton and block respiratory pathways. These formulations act without neurotoxic activity, making them suitable for individuals with sensitivities to conventional insecticides. Application requires thorough saturation of hair and scalp, followed by a 10‑minute dwell time before rinsing.
Natural oils possess limited efficacy but can assist as adjuncts. Tea tree oil (5 %–10 % dilution) and neem oil exhibit acaricidal properties; however, they should not replace FDA‑approved treatments. Vinegar (5 %–10 % solution) can loosen the cement that adheres nits to hair shafts, facilitating mechanical removal, but does not kill the insects.
Environmental control reduces reinfestation risk. Wash all clothing, bedding, and towels used within the previous 48 hours in hot water (≥ 60 °C) and dry on high heat for at least 30 minutes. Items that cannot be laundered should be sealed in plastic bags for two weeks to starve any remaining lice. Vacuum carpets, upholstered furniture, and car seats; discard vacuum bags or clean canisters promptly.
Because lice populations develop resistance, a dual‑approach regimen—chemical or suffocating treatment combined with meticulous nit combing—offers the highest success rate. Follow‑up examinations at 7 and 14 days post‑treatment confirm eradication; any residual activity warrants a second application of the chosen chemical agent.
In summary, a structured protocol that integrates approved insecticidal or silicone‑based products, systematic combing, and rigorous environmental sanitation achieves comprehensive elimination of head lice and their ova.