What should be used to kill lice on a human head? - briefly
A pediculicide shampoo or lotion with 1 % permethrin (or a pyrethrin‑based product) is the primary treatment, applied as directed and left on the scalp for the recommended time. Afterward, a fine‑toothed nit comb should be used to remove any remaining nits.
What should be used to kill lice on a human head? - in detail
Effective eradication of head‑lice infestations relies on a combination of pharmacologic agents, mechanical removal tools, and environmental measures.
First‑line pharmacologic options include over‑the‑counter (OTC) pediculicides containing permethrin (1 %) or pyrethrins with piperonyl‑butoxide. These products are applied to dry hair, left for the recommended duration (usually 10 minutes), then rinsed thoroughly. For resistant populations, prescription‑only treatments such as malathion (0.5 %), benzyl alcohol lotion (5 %), ivermectin lotion (0.5 %), or spinosad (0.9 %) are indicated. Each formulation requires strict adherence to dosage, contact time, and repeat application after 7–10 days to eliminate newly hatched nymphs.
Second, mechanical de‑lousing is essential. A fine‑toothed nit comb, preferably stainless steel with 0.15 mm spacing, should be used on wet hair after chemical treatment. Systematic combing from scalp to tips, repeated every 2–3 days for two weeks, removes live insects and viable eggs.
Third, environmental decontamination reduces reinfestation risk. Wash all bedding, clothing, and personal items used within the preceding 48 hours in hot water (≥ 60 °C) and tumble‑dry on high heat for at least 30 minutes. Non‑washable items may be sealed in airtight bags for two weeks. Vacuum carpets and upholstered furniture to capture detached nymphs.
Safety considerations: avoid applying pediculicides to broken skin, eyes, or mucous membranes. Observe for adverse reactions such as scalp irritation, rash, or respiratory distress; discontinue use and seek medical advice if they occur. Pregnant or lactating individuals should consult a healthcare professional before using prescription agents.
Finally, confirm treatment success by inspecting the scalp 24 hours after the final application. Absence of live lice and viable nits indicates clearance; persistent detection warrants repeat of the chosen regimen or escalation to an alternative agent. Continuous monitoring for at least three weeks prevents unnoticed resurgence.