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Dr Karen Martin
Reviewed by Dr Karen MartinReviewed on 19.10.2023 | 3 minutes read

Head lice are tiny insects that live on human hair and feed on the scalp. They are very common in young school children and their families, and there is no link between head lice and unwashed/dirty hair. The eggs laid by the head lice are what are known as nits. They stick to the hair and hatch after 7 - 10 days. Head lice produce symptoms of an itchy scalp and sometimes a feeling of something moving in your hair.

The only way to diagnose them is to find a live head louse (it will look black and the size of a sesame seed) by combing the hair with a head lice detection comb which you can get from the pharmacy. They like to live close to the scalp and cannot survive for very long away from hair.

Head lice can be treated at home and should be treated as soon as they have been detected.

The best way to treat them is wet combing with a special head lice detection comb. You need to do this every 4 days for 2 weeks to make sure you catch any recently hatched lice (some doctors would advise combing for 3 weeks to be 100% sure you're clear of the critters!).

Wash the hair and then apply a generous amount of conditioner (you can also use olive oil). Leave the conditioner in as you brush the hair with a normal hairbrush to get out the knots, and then use the head lice detection comb, combing from the scalp to the end of the tips of the hair. Check each brushstroke for head lice or nits (tiny black insects or white/brown eggs) and wipe or wash them off the comb if you see any. Do this for all sections of the hair. Wash out the conditioner, then comb one more time through.

If after 2 - 3 weeks of wet combing, there are still head lice detected, then seek guidance from your pharmacist, who can recommend certain lotions/sprays that can kill the head lice. Some of these need to be repeated or paired with combing to remove the dead lice/eggs.

Dry combing can be used to detect head lice in hair but not for treating them.

Doctor’s advice

Is it contagious?

Head lice are contagious. They can be passed on through direct head-to-head contact (they cannot jump or fly) or are less commonly spread via sharing items that come in close contact with hair, such as hats or hairbrushes. If someone in the household has head lice, then all members of the household should be checked and treated if found to have them. There is no way to prevent getting head lice, but tying up long hair can lower the chance of catching them, and once caught, combing with a special comb regularly will help stop the spread. As they do not live long away from hair, you do not need to wash bedding/sheets on a hot wash to get rid of them.

Healthwords pharmacists' top tips

There are insecticide-based products that work by poisoning and killing the lice. These can sometimes cause skin irritation, and so may not be preferable to those with sensitive skin.

Other products, such as Nix lotion, work by coating and drying out the lice and are generally milder on the skin. There are a number of natural products that are also available.

Am I fit for work?

If you have head lice, you are still fit for work. Children are also still able to go to school.

When should I see my doctor?

There is no need to see your doctor for head lice. This can be managed by you at home with a special comb or treatment from the pharmacy.

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This article has been written by UK-based doctors and pharmacists, so some advice may not apply to US users and some suggested treatments may not be available. For more information, please see our T&Cs.
Dr Karen Martin
Reviewed by Dr Karen Martin
Reviewed on 19.10.2023
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