Head lice (Pediculus humanus capitis) are obligate human ectoparasites that affect millions of UK schoolchildren every year — and the adults around them. They are not a sign of poor hygiene (lice prefer clean hair), they don’t transmit disease, and they are entirely treatable. Knowing the most effective treatments and how to use them correctly prevents the frustrating cycle of reinfestation.
Detecting Head Lice: The Detection Comb Method
The most reliable way to detect head lice is the detection combing method — not visual inspection of dry hair, in which lice are difficult to spot. Method: wash hair normally, apply conditioner (makes lice temporarily immobile and easier to comb out), comb through small sections with a fine-toothed detection comb (plastic or metal, teeth no more than 0.3mm apart), wiping the comb on white paper or tissue after each stroke. Live lice on the tissue confirm active infestation; eggs (nits) attached to hair shafts, particularly within 1cm of the scalp, indicate active or recent infestation. Only live lice (moving) confirm active infestation — empty egg cases farther from the scalp indicate previous infestation that may have resolved.
Treatments That Work
Wet combing (“Bug Busting”): applying conditioner and combing meticulously every 3–4 days for 2 weeks removes lice at each life cycle stage. Effective when done consistently and correctly; the main limitation is that it requires 30–45 minutes of careful combing per session. A systematic review found comparable efficacy to insecticide treatments when performed correctly. Dimeticone 4% (Hedrin, Lyclear Sensitive): physical insecticide — coats lice and blocks their spiracles (breathing holes), causing asphyxiation. No risk of resistance. Licensed for use from 6 months. Apply to dry hair, leave for 8 hours (or overnight), shampoo off; repeat after 7 days. First-line recommendation in many NHS guidelines. Isopropyl myristate/cyclomethicone (Full Marks): physical action — dissolves the louse’s exoskeleton. Apply to dry hair, 10 minutes, comb through, shampoo. Effective; no resistance. Malathion 0.5% (Derbac-M): chemical insecticide; still effective but chemical insecticides have significant regional resistance in UK lice populations. Less recommended as first-line than physical treatments.
Preventing Reinfestation
Lice spread exclusively through prolonged direct head-to-head contact — not through sharing brushes, hats, or pillows (lice cannot survive off the human head for more than a few hours). Treatment of all household members simultaneously (whether or not they show symptoms) prevents ping-pong reinfection. Inform the school so other parents can check and treat their children. Weekly detection combing throughout primary school years catches reinfestation early.
Frequently Asked Questions About Head Lice
My child keeps getting lice even after treatment — why?
The most common reason is reinfestation from an untreated contact (sibling, classmate) rather than treatment failure. Simultaneous treatment of all household members and notifying the school is essential. Check treatment technique — dimeticone must coat all hair including at the roots; incomplete application leaves surviving lice. A second-line physical treatment (switching product) is appropriate if the first genuinely fails.
Do I need to wash all bedding and soft toys?
This is widely recommended but not evidence-based — lice cannot survive off the human scalp for more than a few hours and are unlikely to transfer from inanimate objects. Washing bedding is a sensible precaution but won’t make or break treatment success. Focusing effort on treating affected people is far more important.
Browse head lice treatments including Hedrin and Full Marks at Huncoat Pharmacy. Related: Childhood Eczema.
At Huncoat Pharmacy: Pharmacy First, Browse head lice treatments.