What should you know about untreated head lice?

Head lice live on the scalp and feed on blood. Eggs, called nits, are attached close to the hair roots, and live crawling lice are the clearest sign of an active infestation. Itching may be strong, including Itching Worse At Night, but some people have little or no itch at first.

Ongoing scratching can cause small sores, crusting, and bacterial infection. Lice do not jump or fly; they mainly spread through close hair-to-hair contact. Brushes, hats, and bedding can also be involved when recently used, so household advice should be specific rather than based on panic cleaning.

Arrange a GP Consultation or pharmacist assessment to confirm live lice and choose an appropriate product or wet-combing plan. Follow the treatment instructions exactly, including any repeat application or combing schedule. Check close household contacts, avoid sharing combs and hair accessories, and wash or isolate recently used items according to local advice. Treating without finding live lice can expose the scalp to unnecessary products.

See Head Lice Treatment, Head Lice, and Itchy Scalp for related guidance.

Seek medical advice if the scalp has pus, spreading redness, marked swelling, painful sores, or fever, or if itching continues after correctly completed treatment. Ask for review when live lice remain despite following instructions, because incorrect application, reinfestation, or a different scalp condition may be responsible.

Ask: Did you find live lice or only old nits? Which treatment suits my age and scalp? When should it be repeated? Who should be checked at home? What should I do if the itching continues after treatment?