Head lice and nits?

Head lice are tiny grey/brown insects. They are about the size of a sesame seeds and cling to hairs, close to the scalp. They lay eggs which hatch after 7-10 days. It takes about 10 days for a newly hatched louse to grow to an adult and start to lay eggs. Nits are the empty white egg shells which are left when the lice hatch. They look like dandruff, but stick to hair. Unlike dandruff, you cannot easily brush out nits.

Who gets head lice?

Head lice are common in children, but can affect anyone. 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?

Many people with head lice do not have any symptoms. An itchy scalp occurs in some cases. This is due to an allergy to the lice, not due to their biting. It often takes about three months for an itch to develop after you are infested with lice. Therefore, you may not notice that you have head lice for a while. They do not wash off with normal shampoo and do not cause any other medical problems.

How can you tell if you have head lice?

Head lice are difficult to find just by looking in the hair. If you suspect that your child has head lice, it is best to do detection combing. Some people advise that you do this to children's hair regularly, about once a week.

Detection combing: wet hair method

This will take 5-15 minutes to check each head, depending on hair length and thickness. It is also used as a treatment for head lice.

■ Wash the hair in the normal way with ordinary shampoo.

■ Rinse out the shampoo and put on lots of ordinary conditioner.

■ Comb the hair with a normal comb to get rid of tangles.

■ When the hair is untangled switch to a detection comb. This is a special finetoothed comb. Most pharmacies stock detection combs.

■ Slot the teeth of the comb into the hair at the roots so it is touching the scalp.

■ Draw the comb through to the tips of the hair.

■ Make sure that all parts of the hair are combed.

■ Check the comb for lice after each stroke.

■ If you see any lice, clean the comb by wiping it on a tissue. After the whole head has been combed, rinse out the conditioner.

■ Repeat the combing procedure in the wet hair to check for any lice that might have been missed the first time.

Detection combing: dry hair method

This will take 3-5 minutes to check each head, depending on hair length and thickness. Although useful to detect head lice, it is not useful as a treatment

■ Straighten and untangle the dry hair using an ordinary comb.

■ Once the comb moves freely through the hair switch to a detection comb.

■ Starting from the base of the scalp, comb the hair from the scalp down to the end of the hair. Comb each section of hair 3-4 times before moving to an adjacent section.

■ Look for lice as the comb is drawn through the hair.

■ If a possible louse is seen, trap it against the face of the comb using the thumb. This avoids the risk of the louse being repelled by static electricity as the comb is withdrawn from the hair.

■ Continue combing the hair section by section until the whole head of hair is combed through.

What are the treatment options for head lice?

Treatment is needed only if you see live lice. Nits do not always mean that you are infested as they can stick to hair when lice are gone.

There are several solutions available for clearing head lice. The treatment chosen depends on your personal preference. Each treatment has a good chance of clearing head lice if applied or done correctly and if all affected people in the household are treated at the same time. The more common treatments are briefly discussed below but for full details read the instructions that come with the packaging.

Dimeticone lotion

Dimeticone is a silicone-based product. It is classed as a physical insecticide and is not classed as a chemical insecticide. Dimeticone has a good safety record and is widely used in cosmetics and toiletries. You should apply the lotion twice - seven days apart. Each application is left on for at least eight hours and then washed off with shampoo and water.

It works by blocking the tubes used by the lice to breathe and by blocking the way the lice pass out water, which kills them. It does not kill unhatched eggs. This is why two applications are needed, seven days apart. The second application makes sure that any lice that hatch from eggs which survived the first application will be killed before they are old enough to lay further eggs. It is suitable for all ages, those with skin conditions, and those with asthma. You can also buy dimeticone over-the-counter.

Wet combing treatment

Wet combing is a way of removing head lice without having to use a lotion to kill them. The method is similar to detection combing but you need to do this several times, four days apart. It takes up to an hour to do a wet combing session properly.

You need to do the above routine at least four times, every four days. The number of sessions required depends on the last time you see lice. The first combing session should remove all hatched head lice, but does not remove eggs. Subsequent sessions clear newly hatched lice. Keep doing the combing sessions every four days until you have had three sessions where no lice are detected. The downside to this treatment is that it is time-consuming.

Isopropyl myristate and cyclomethicone solution

This is classed as a physical

insecticide and is not classed as a chemical insecticide. It works in a similar way to dimeticone. You apply the solution to the scalp and leave in place for 10 minutes. The hair is then combed with a finetoothed comb to remove lice. Then wash using shampoo to remove the solution. Treatment should then be repeated in seven days time. The second application makes sure that any lice that hatch from eggs which survived the first application will be killed before they are old enough to lay further eggs.

This treatment is suitable for those with asthma. It is not suitable for children younger than two years of age or people with skin conditions.

Coconut, anise, and ylang ylang (CAY) spray

This too is a physical insecticide and works in a similar way to dimeticone. You apply the spray to the hair and scalp and leave in place for 15 minutes. The hair is then combed with a fine-toothed comb to remove lice. Then wash using shampoo to remove the spray. Treatment should then be repeated in seven days time. The second application makes sure that any lice that hatch from eggs which survived the first application will be killed before they are old enough to lay further eggs. This treatment is not suitable for children younger than two years old, people with skin conditions, or those with asthma

Malathion 0.5% aqueous liquid

Malathion is a chemical insecticide that has been used for many years to treat head lice. The malathion kills the lice. There are various brands. It is suitable for all ages and those with skin conditions. You should apply the lotion twice seven days apart. Each application is left on for at least 12 hours and then washed off with shampoo and water. The second application makes sure that any lice that hatch from eggs which survived the first application will be killed before they are old enough to lay further eggs.

Do family and friends need treatment?

Only if they have head lice. All people in the same home, and other close head-tohead contacts of the previous 4-6 weeks should be contacted. Tell them to look for lice and treat if necessary. All people with head lice in the same home should be treated at the same time. This stops lice being passed around again.

What about school?

Children with head lice should carry on going to school. Lice do not spread quickly through schools. Alarming head lice letters from schools are usually unhelpful. You need close headto-head contact to pass lice on to others. Young children who play closely together may pass lice on. If your child has head lice, a common-sense approach is to tell the parents of their close friends to look out for lice in their children.

Can head lice be prevented?

If you do detection combing of children's hair every week or so, you will detect head lice soon after they have affected the hair. You can then start treatment quickly and reduce the risk of passing them on to others.

Some other points about head lice

Use an anti-lice treatment only when you are sure that you have head lice. Do not use them to prevent head lice.

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

After treatment it may take 2-3 weeks for the itch to go.

Nits may remain after lice have gone. They are empty eggshells and stick strongly to hair. They will eventually fall out. If you prefer, a fine-toothed 'nit comb' can remove them.