Head lice are a fact of life for most UK school-age children — and the families of almost every child will encounter them at some point. They don’t indicate poor hygiene, they spread very easily, and with the right treatment they can be cleared quickly.

Understanding Head Lice

Head lice (Pediculus humanus capitis) are tiny parasitic insects that live on the scalp and feed on blood. They are grey-brown and approximately 1–3mm long as adults. Eggs (nits) are glued to hair shafts close to the scalp and hatch in 7–10 days. The life cycle from egg to egg-laying adult takes about 18 days. Head lice cannot jump, fly or survive off the head for more than 24 hours. Transmission is almost entirely through direct, prolonged head-to-head contact.

Detection: How to Check Properly

Itching is caused by an allergic reaction to louse saliva and develops 4–6 weeks after first infestation — many infestations are asymptomatic initially. The only reliable way to detect lice is detection combing: apply conditioner to dry, detangled hair (the conditioner slows the lice). Use a fine-toothed detection comb (spacing of 0.2–0.3mm). Section hair and comb from root to tip over a pale surface or paper towel. Check the comb after each stroke for lice or eggs. Repeat weekly for early detection.

Treatment Options: What Works Best

Dimeticone (Hedrin Once, NYDA) — works by physical action: coats the lice, blocking their breathing apparatus and causing them to die. No resistance issue (it’s not a chemical kill mechanism). Hedrin Once is left on for 8 hours (overnight), then shampooed out. Repeat after 7 days. Highly effective: 97% efficacy in clinical trials. Isopropyl myristate/cyclomethicone (Full Marks Solution) — also physical action. Apply for 10 minutes, comb through, shampoo off. Repeat after 7 days. Fast and effective. Wet combing alone — if you prefer no products. Section conditioner-coated hair and comb thoroughly every 4 days for 2 weeks. Labour-intensive but effective if done with sufficient thoroughness and frequency. Pyrethroid insecticides (permethrin, phenothrin) — chemical treatments that are no longer recommended as first-line due to widespread resistance. Many UK louse populations are resistant.

The 7-Day Repeat Treatment Rule

All physical treatments must be repeated 7 days after the first application. This is because the treatment kills live lice but may not kill all eggs. Eggs that hatch after the first treatment will be killed by the repeat application before they can lay new eggs — breaking the life cycle.

Preventing Reinfestation

Regular detection combing (weekly) catches new infestations early. Hair worn up (plaits, buns) reduces contact surface area. Notify the school so other parents can check — this is essential to break the cycle of reinfestation. Only treat those with live lice confirmed by detection — prophylactic treatment is not recommended and increases resistance.

Shop Head Lice Treatments including Hedrin and Full Marks at Chemist 2 Customer.