What causes lice on the head and how can they be treated? - briefly
Head lice spread through direct scalp contact or sharing items such as hats, brushes, and bedding; they thrive in warm, close‑quarters environments. Effective control combines a FDA‑approved insecticide shampoo or lotion with meticulous wet combing to remove nits, followed by washing clothing and linens in hot water.
What causes lice on the head and how can they be treated? - in detail
Head lice infestations arise when adult female insects lay eggs (nits) on hair shafts close to the scalp. The eggs hatch in about seven to ten days, releasing nymphs that mature into reproductive adults within another week. Direct head‑to‑head contact provides the most efficient route for transfer; sharing hats, brushes, helmets, or scarves can also spread the parasites. Crowded living conditions, limited access to hygiene products, and frequent close contact among children increase prevalence. Lice survive only a few days off the host, so prolonged environmental exposure is not a primary source of infection.
Effective management combines chemical and mechanical strategies. Recommended steps include:
- Pediculicide application – Use a shampoo, lotion, or spray containing permethrin (1 %) or pyrethrin with piperonyl butoxide. Follow label instructions precisely, covering the scalp and hair for the stipulated contact time before rinsing.
- Prescription options – For resistant cases, apply a lotion with ivermectin (0.5 %) or a mousse containing benzyl alcohol (5 %). These agents act on the nervous system of the lice and are approved for use in children over two years.
- Nit removal – After the initial treatment, comb wet hair with a fine‑toothed nit comb at 2‑day intervals for ten days. This eliminates unhatched eggs and reduces reinfestation risk.
- Repeat treatment – Perform a second application of the chosen pediculicide 7–10 days after the first to target newly hatched nymphs that survived the initial dose.
- Environmental control – Wash clothing, bedding, and towels used within the previous 48 hours in hot water (≥ 60 °C) and dry on high heat. Items that cannot be laundered may be sealed in a plastic bag for two weeks to ensure lice mortality.
Monitoring the scalp for live insects or viable nits for two weeks post‑treatment confirms success. If live lice persist, consult a healthcare professional for alternative medications or combination therapy. Proper education of caregivers and avoidance of sharing personal items are essential preventive measures.