Head Lice and Nits

Head lice are tiny grey/brown insects. They are about the size of a sesame seed (the seeds on burger buns). Head lice cling to hairs but stay close to the scalp which they feed off. They lay eggs that hatch after 7-10 days. It takes about 10 days for a newly hatched louse to grow to an adult and start laying eggs.

Nits are the white empty egg shells that are left when the lice hatch. Nits can look like dandruff but stick strongly to hair. Unlike dandruff, nits cannot be brushed out easily.

Who gets head lice?

Head lice are common in children but can affect anyone at any age. They are not a sign of dirty hair or poor hygiene. Close 'hair to hair' contact is usually needed to pass lice on. Head lice cannot jump or fly but walk from one head to another. They soon die when away from hair and do not live in clothes, bedding, etc. Most head lice infections are caught from family or close friends who are not aware that they have head lice.

What are the problems with head lice?

Most people with head lice have no symptoms and are not aware they have them. An itchy scalp occurs in about 1 in 3 affected people. This is due to an allergy to the lice, not due to them biting. Itch commonly takes several months to develop after infection. So, lice may go unnoticed and be passed on to others for some time. Head lice and nits will not wash off with normal shampoo. Head lice do not cause any other medical problems. In most affected people the head is not 'crawling with lice'. Commonly there are less than 12 lice present.

How can you tell if you have head lice?

Lice can just about be seen with the naked eye. However, they are difficult to find just by looking in the hair. 'Detection combing' is the best way of finding head lice if they are suspected. Some people advise to do this on children's hair regularly, about once a week.

Wash the hair in the normal way with ordinary shampoo and partly dry with a towel.

Comb with a normal comb first to get rid of tangles.

Then use a detector comb with the hair damp, not dripping. This is a special fine toothed comb that is available at pharmacies. (The teeth of normal combs are too far apart.)

Start with the comb touching the scalp next to the roots of the hair. Comb downward to the ends of the hair. Repeat this working around each part of the head combing each area carefully from the scalp downwards.

Lice will be caught in the comb and may be seen. Have a look at the comb teeth for lice after each stroke in a good light. A magnifying glass may help.
Wipe the comb with a white cloth or tissue after each stroke. Head lice will show up as dark bits on the white cloth.

Comb over a white surface such as white paper. This is so that any head lice that are combed out without getting stuck on the teeth of the comb are easy to see.

It takes about 10-15 minutes to do detection combing properly.

If you find dark bits and are unsure if they are lice, stick one to a piece of white paper with clear sticky tape. Show this to a doctor, school nurse or practice nurse.

What are the treatment options for head lice?

Treatment is only needed if one or more live moving lice are seen. Nits (empty eggshells) do not always mean infection. Nits stick to hair even when lice are gone or after treatment.

Chemical treatment
Lotions or a cream rinse that kill lice are available at pharmacies or on prescription. Head lice shampoo is not very effective and is not advised. Lotions come in water or alcohol bases. Alcohol based lotions are slightly more effective but water based lotions should be used by people with asthma, eczema or broken skin. Alcohol based lotions are also flammable and should not be used anywhere near naked lights, cigarettes, fires or flames. Be careful with children near fires who have alcohol lotion in their hair.

About 50ml of lotion is needed per person. Up to 150ml is needed for thick hair.
Follow the instructions on the packet carefully. This may include the following. For lotions: part the hair near the top. Pour a few drops onto the scalp. Rub well into the hair. Part the hair again a little further down and repeat. Repeat this until the whole scalp is covered. Apply to hair down to where a pony tail band would be. Put lotion on dry hair and leave on for the full time advised. This is usually overnight (12 hours). Wash off the next day. For cream rinses: the instructions may be slightly different. For example, apply to damp hair and the time left on may be different.

Do not go swimming before putting on lotion. The chlorine from the swimming pool may stop the lotion working.

Do not use a hairdryer after applying the treatment. Let the hair dry naturally.
Re-apply the same treatment after 7 days. Although lice are usually killed by one application, not all eggs may be. The second application makes sure that any lice that hatch from eggs that survived will be killed before they are old enough to lay further eggs.

Inspect the hair by detection combing 2-3 days after the second application. If any live moving head lice are found despite treatment then see a doctor or nurse for advice.

Wet combing treatment
This treatment is popular but it is not clear how successful it is compared to treatment with chemical lotions. After washing the hair apply lots of hair conditioner. Then comb the hair as described above with the special detector comb. Lice cannot grip hair that is slippery with conditioner. The special comb should remove them easily. Wipe the comb after every stroke. It can take up to 30 minutes to thoroughly comb all the hair. Then rinse out the conditioner. This wet combing routine needs to be done every 3-4 days, 4 times in all.

The first combing session should remove all hatched head lice but does not remove eggs.

Any young lice that hatch from eggs after the first session are removed at the second, third and fourth sessions. This is why it is important to do the full 4 sessions.

If full-grown lice are seen at the second, third or fourth session, this means that some had been missed on the first session or re-infection from someone else has occurred. If this occurs, the number of treatment sessions should be increased. Basically, following any session where adult head lice are found, there should be 3 further sessions at 3-4 day intervals where no adult lice are seen.

Fuller details of wet combing treatment ('bugbusting') can be obtained from:
Community Hygiene Concern, 160 Inderwick Road, London, N8 9JT
Tel: 020 8341 7167 Web: www.nits.net

Do I need to treat family and friends?

All people in the same home and other close 'head to head' contacts of the previous 4-6 weeks should be contacted. Tell them to look for lice by detection combing (described above). Only people with head lice should be treated. (It used to be advised to treat all close contacts even if they had no symptoms. This has changed to just treating people with definite head lice infection.) All people with head lice in the same home should be treated at the same time.

What about school?

Children with head lice should carry on going to school. Contrary to popular belief, head lice do not spread quickly through schools. Alarming 'head lice letters' from schools are unhelpful. As mentioned, close 'head to head' contact is needed to pass lice on to others. Young children who are 'best friends' and play closely together may pass lice on. A common sense approach may be to inform parents of the close friends of an affected child.

Can head lice be prevented?

There is no good way of preventing head lice. Lice repellent sprays are not thought to be very effective. Regular detection combing of children's hair will detect lice infection early. This means treatment can be started early which means less chance of passing them on to others.

Some other points about head lice

Use chemical treatments only when you are sure that you or your child have head lice. Do not use chemical treatment to prevent head lice or 'just in case'. Frequent use of anti-lice chemicals may cause a build up of small amounts of chemical in the body. The risk of harm from this is very small but it is best to use chemical treatments only when infected.

A common reason for head lice to recur in one person is because close contacts (family and close friends) are not checked and treated if they too have head lice. The treated person is then likely to get head lice back again from untreated family or friends.

An itchy scalp may take 2-3 weeks to go fully after lice have gone following treatment.

Nits are not removed with treatment. They are empty egg shells and stick to hair strongly. They will eventually go after lice have gone. A metal fine toothed 'nit comb' can remove them if you prefer.

A final reminder - alcohol based lotions are flammable. Some children have been badly burnt as their hair caught fire whilst being treated. Keep children away from fires, cigarettes, flames, etc, whilst lotion is in their hair.

Extract from Mentor Plus copyright OUP, EMIS and Authors 1999