How should lice be treated in people? - briefly
Apply a pediculicide—commonly 1 % permethrin shampoo or 0.5 % malathion lotion—according to label instructions, then remove remaining nits with a fine-toothed comb and repeat treatment after 7–10 days. Wash clothing, bedding, and personal items in hot water or dry them on high heat to eliminate any surviving parasites.
How should lice be treated in people? - in detail
Effective management of human lice infestations requires accurate identification, appropriate therapeutic agents, and environmental control. Diagnosis is confirmed by visual examination of live lice or viable nits attached to hair shafts within 1 cm of the scalp. Once confirmed, treatment proceeds in three phases: pharmacologic therapy, mechanical removal, and decontamination of personal items.
Pharmacologic options fall into two categories. First‑line topical pediculicides contain either permethrin (1 %) or pyrethrin + piperonyl‑butoxide. Application follows manufacturer instructions, typically a 10‑minute exposure before rinsing. Second‑line agents include malathion (0.5 %), benzyl alcohol lotion (5 %), ivermectin (0.5 % cream), or spinosad (0.9 %). Resistance to permethrin and pyrethrin is documented; in such cases, a non‑neurotoxic product such as benzyl alcohol or ivermectin should be selected. Oral ivermectin (200 µg/kg) is an alternative for extensive infestations or when topical use is contraindicated.
Mechanical removal complements chemical treatment. After the initial application, a fine‑toothed nit comb should be used on wet hair to extract live insects and nits. The combing process is repeated every 2–3 days for at least two weeks, covering the entire scalp. For pubic or body lice, thorough washing of the affected area with soap and water, followed by gentle scratching with a disposable instrument to dislodge specimens, is recommended.
Environmental measures reduce re‑infestation risk. Clothing, bedding, and towels used within the preceding 48 hours must be laundered in hot water (≥ 60 °C) and dried on high heat. Items that cannot be washed should be sealed in plastic bags for two weeks. Vacuuming of upholstered furniture and carpets eliminates stray nits. Personal items such as combs, brushes, and hats require disinfection with alcohol (≥ 70 %) or soaking in hot water.
Follow‑up assessment occurs 7–10 days after the initial treatment. Absence of live lice confirms cure; residual nits without viable insects may be removed manually. A second application of the chosen pediculicide is advised if live lice persist. For households with multiple members, simultaneous treatment prevents cross‑contamination.
Special populations demand adjusted protocols. In infants under two months, topical agents are contraindicated; a combination of manual removal and washing of clothing suffices. Pregnant or lactating individuals should avoid neurotoxic pediculicides; benzyl alcohol or dimethicone‑based lotions are preferred. Immunocompromised patients require prompt eradication to avoid secondary bacterial infection.
In summary, successful eradication of lice in humans integrates evidence‑based topical or oral agents, systematic nit combing, rigorous laundering of personal items, and targeted follow‑up. Adherence to these steps minimizes recurrence and limits transmission within close contacts.