What to know when head lice seem severe or persistent

Head lice live close to the scalp and pass mainly through direct hair-to-hair contact. They do not reflect poor hygiene. Finding a live crawling louse is the clearest way to confirm an active infestation; empty egg cases can remain attached after lice are gone.

Head lice often present with scalp itching, disturbed sleep, a crawling sensation and scratch marks, although some people have few symptoms. Itching can continue after effective treatment because the scalp remains irritated. Seeing only fixed white specks does not prove active lice, as dandruff and old egg cases can be mistaken for eggs.

Ongoing live lice may result from incomplete application, missed repeat treatment when the product requires it, reinfestation from close contact, or reduced response to a chosen product. Using extra product or applying it more often than directed can irritate the scalp without solving the cause.

Check damp, conditioned hair systematically with a fine detection comb, concentrating behind the ears and at the nape. If live lice are found, use a suitable lice treatment exactly as its instructions state. Ask a pharmacist or clinician which option fits the person's age, pregnancy status, allergies and previous treatments.

Examine household members and close contacts, treating those with confirmed active lice at the same time. Avoid sharing combs, brushes, hats and hair accessories until addressed. Clean items that had recent close contact with hair, but extensive spraying of rooms or furniture is unnecessary and may expose people to irritating chemicals.

Seek clinical advice if live lice remain despite correctly completed treatment, if you are unsure whether the specks are lice eggs, or if treatment is needed for a baby, during pregnancy, or for someone with significant scalp disease.

Prompt assessment is appropriate for spreading redness, warmth, pus, painful crusting or fever, which can follow bacterial infection of scratched skin. Stop a product and seek urgent help if it causes breathing difficulty, faintness, or swelling of the face, lips or tongue.

Bring the product name and a record of how it was used. Ask whether live lice are still present, whether the application method was suitable, when rechecking is needed, and which alternative avoids repeating the same active ingredient unnecessarily.