How can lice be treated? - briefly
Effective treatment relies on applying a pediculicide shampoo or lotion—commonly permethrin or pyrethrin—followed by meticulous combing with a fine-toothed nit comb to eliminate eggs. Alternative measures include dimethicone‑based formulations or oral ivermectin for infestations resistant to standard agents.
How can lice be treated? - in detail
Effective elimination of head lice requires a combination of chemical, mechanical, and environmental measures.
Topical insecticides remain the primary approach. Permethrin 1 % cream rinse applied to dry hair for ten minutes, followed by thorough rinsing, achieves high mortality in susceptible populations. Pyrethrin formulations combined with piperonyl butoxide provide an alternative for cases of permethrin resistance. Malathion 0.5 % lotion, left on the scalp for eight to twelve hours, serves as a second‑line option when resistance to pyrethroids is documented. Ivermectin 0.5 % lotion, applied for ten minutes and rinsed, offers a prescription‑only solution with a distinct mechanism of action. Benzyl alcohol 5 % lotion, acting as a neurotoxic agent, requires a single eight‑hour exposure and is suitable for children over six months. Spinosad 0.9 % suspension, left on the hair for ten minutes, provides rapid knock‑down of both lice and nits.
Mechanical removal complements chemical treatment. A fine‑toothed nit comb, used on wet, conditioned hair, extracts live insects and attached eggs. Repeated combing at 2‑day intervals for a fortnight reduces residual infestation. Manual removal should be performed on all family members, regardless of symptom presence.
Environmental decontamination minimizes re‑infestation. Items that cannot be washed—such as hats, hair accessories, and upholstery—should be sealed in plastic bags for at least 72 hours, a period exceeding the survival window of lice off the host. Washable fabrics may be laundered at 55 °C or higher; dry‑cleaning is an acceptable alternative. Vacuuming of carpets, mattresses, and vehicle seats removes detached insects.
A second application of the chosen topical agent is recommended seven to ten days after the initial treatment, targeting newly hatched lice that survived the first exposure. Monitoring for treatment failure involves visual inspection of the scalp and hair at three‑day intervals; persistent live insects after two treatment cycles warrant consultation with a healthcare professional for alternative regimens.
Resistance surveillance informs product selection. In regions with documented pyrethroid resistance, preference should shift toward ivermectin, spinosad, or non‑chemical strategies such as dimeticone‑based lotions, which suffocate lice without neurotoxic action.
Adherence to the outlined protocol—appropriate topical agent, systematic nit removal, thorough environmental management, and scheduled retreatment—achieves comprehensive control of head‑lice infestations.