Head lice are grey or brown insects that live close to the scalp on human heads. They are 1mm to 3mm long.

The insects lay eggs. Each egg is glued to a hair, often near the root. Nits are empty eggs left behind when lice hatch. They can be white, yellow or brown.

The main symptom is itching, but only about 1 in 3 children with head lice have an itch.

You’ll need to treat your child if they have head lice. There’s no need to keep them home from school.

Check for head lice

The best way to find head lice is to check your child’s hair every week. Comb through their hair with a ‘detection comb’ – you can buy this from a pharmacy.

1. Wash the hair with ordinary shampoo.
2. Apply lots of conditioner and comb it through with an ordinary comb. This makes lice wet, which keeps them still.
3. Put the teeth of the detection comb into the hair at the roots and comb down to the ends.
4. Work through the hair, section by section, checking the comb each time.
5. Rinse off the conditioner.
6. Repeat combing while the hair is still wet.

Treatment for head lice

The best way to treat head lice is with a medicated lotion. You can buy these at a pharmacy. Your pharmacist can advise you on which one to buy.

If you find lice, check everyone in the family and let people who have been in close contact know, so they can check as well. You only need to treat people who have lice.

Using the lotion

There will be instructions in the box on how to use the treatment. Talk to your GP, midwife or obstetrician first if you or someone in your family is pregnant.

Treat everyone with lice at the same time so that untreated people don’t re-infect the treated ones.

Repeat the treatment a week later, even if the instructions recommend only 1 application. This is important as there is no treatment guaranteed to kill unhatched eggs. Unhatched eggs will hatch over 7 to 10 days.

After treatment

Check the hair again 2 days after the treatment, to make sure it has worked.

If you find nits, but don’t find lice, don’t treat again. Nits may be left behind on the hairs but this does not mean the treatment has failed. Only treat if you find living, moving lice.

If you find lice after the treatment, there could be 2 reasons:

• your child has been re-infected with lice
• the treatment wasn’t carried out correctly

Check the whole family again and treat all those with lice. If you still find lice, ask a GP or pharmacist for advice.

Your child might still scratch after the treatment. This doesn’t mean they have lice, but check your child’s head to be sure. Do not treat again unless you find live lice. Overusing the treatment can make the scalp flaky and itchy.

You cannot prevent head lice

Anyone with hair can get head lice. They aren’t fussy about clean or dirty hair. Children tend to get them more than adults.

Lice can spread when heads are touching for a minute or more. The lice climb through the hair from one head to another. They don’t jump, fly or swim. Lice can also spread through sharing:

• combs
• brushes
• caps
• other clothing

Lice that fall from the head are usually dying and harmless. However, lice caught on combs can re-establish if they are combed back on within 48 hours.

To reduce the risk of head lice spreading:

• avoid head-to-head contact
• tie back long hair