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HealthInfo Waitaha Canterbury

Head lice & nits

Ngā kutu

Head lice are small insects that live on the hair on your head. Nits are the empty egg cases that head lice have hatched from.

Head lice is a common but not serious health problem. They can affect anyone, but they're most common in young tamariki (children) between the ages of 4 and 14.

Head lice only live on humans.

Causes of head lice

You can pick up head lice from close head-to-head contact. This commonly happens within whānau (families) or between tamariki at school. Head lice cannot jump or fly so they spread from person to person by crawling between their hair.

Diagnosing head lice

Head lice can make your scalp (head) feel itchy. It can also feel like there is something moving in your hair.

Some people do not have any symptoms. Also, an itchy scalp doesn't always mean you have head lice. Other conditions such as eczema or dandruff can also cause an itchy scalp.

To be sure it's head lice, it's important to look for the lice and nits. Look behind your ears, on the top of your head and around the hairline at the back of your neck. The lice may be hard to see but the empty egg cases may be easier to see. They look like white grains.

Treating head lice

You can treat head lice without going to see your general practice team.

Wash your hair then apply hair conditioner and do not rinse it out. While your hair is still wet, comb it with a fine-tooth comb. This is called wet combing. This page shows you how to do this. Wet combing is an effective way of physically removing the lice and nits.

Another good treatment is 4% dimethicone lotion. Your general practice team can prescribe this. You only need to put it on your child's head twice with a week between each use. This page gives details of how to use it.

Dimethicone is not an insecticide. It kills head lice by suffocation and by disrupting the ability of the head lice to regulate water. It's unlikely that head lice will develop resistance to dimethicone as they can with other products.

You can buy head lice shampoos from supermarkets and pharmacies. These contain an insecticide to kill the lice and you usually need at least two applications. They may not work as well as other treatments since head lice can become resistant to them.

Anyone who has had close contact with your tamaiti (child) should be checked for head lice and treated at the same time if needed.

Preventing head lice

It's very difficult to prevent head lice. Check your tamaiti each week to make sure they do not have a new infection.

Tying long hair back and checking weekly for lice using the conditioner and comb method can help prevent the spread of head lice.

Washing clothing and bedding in hot water is unlikely to help prevent the spread of head lice.

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Written by HealthInfo clinical advisers. Last reviewed January 2022.


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Page reference: 49699

Review key: HILMB-49699