|
Written by Dr Gillian Rice, GP
|
|||||||||||||||
What are lice?
Head lice cling to hair and are usually found on the scalp. They live on blood from the host, which they get by biting through the scalp. Adult lice mate. The female then lays eggs that are firmly attached to hair close to the scalp and can be very difficult to remove. After seven or eight days the baby louse hatches out of the egg, leaving a shiny white empty eggshell (nit), which may be found anywhere along a strand of hair. What causes an infection of head lice? Infection with head lice is a very common problem in the UK, especially among school children. Lice pass from one person to another during direct head-to-head contact. This is because lice cannot jump, fly or hop; they can only transfer to another head by walking along strands of hair. Children whispering secrets at school or families enjoying a cuddle at home provide head lice with the ideal opportunity to travel from one head to the next. Lice seen on pillows, hats or chair backs are not capable of transferring to another person. The belief that head lice are associated with poor hygiene is common but misfounded. Lice are equally likely to be found on clean or dirty hair. Head lice should be seen as nothing more than an unpleasant inconvenience that can be treated. What symptoms do head lice cause? Bites from head lice can cause intense itching and irritation on the scalp, but these symptoms may not appear until at least two months after the lice move in. A rash at the nape of the neck may also develop. What is the best way of looking for head lice? You can part the hair and look for nits, but the lice will move quickly into hiding. The best way to search for head lice and nits is to buy a specially designed detection (nit) comb from a pharmacy. This is a fine-toothed plastic comb with spacing of less than 0.3mm. You can check for lice on dry or wet hair.
People with thick hair often find conditioner makes it easier to get the nit comb through. If you have curly hair you may find that oiling rather than wetting hair makes it easier to use the nit comb effectively. You can do this with one tablespoonful of olive oil. What if I find lice? Check every other member of the family, including any adults who have close contact with the child. You can work out when the lice first moved in by judging how many centimetres from the scalp you find the nits. Hair grows at about 1cm a month; so a nit 2cm from the scalp was laid about two months ago. It's also helpful to tell the school and parents of any other child who may have had head-to-head contact with your child, so that other children can be checked for lice. How are head lice treated? The three main treatments for head lice are listed below, but no method is 100 per cent effective. You should only start chemical treatment if you find a live louse on your child's head. If you only find the hatched and empty eggshells (nits), these may be the sign of a previous batch of lice that have already been eradicated.
Insecticides that kill head lice are available in lotion form. You can buy them from the pharmacy or get them on prescription. There are two types available in the UK: For them to work, you must follow the manufacturer's instructions to the letter. Treatment failures may result from not using the product in the correct way, for example:
Lice eggs are more difficult to kill because the insecticide may not be able to penetrate the eggshell. You will need to repeat the treatment after seven days to kill any lice from eggs that survived the first application. Unfortunately there is evidence that head lice have become resistant to some of the insecticides. There are also concerns about the environmental effects of overusing insecticide preparations (which are the same as some agricultural pesticides in general use).
These are relatively new products that work in a different way to conventional insecticides for head lice. The market in this area has grown over the last few years because these products have proved very effective at eradicating lice without side effects or problems with resistance. Some are effective in as little as ten minutes. Instead of poisoning the parasites by chemical means, these products kill the lice by physically coating their surfaces and smothering them. As these products work in this physical way, head lice cannot become resistant to them. Not all the products kill eggs, so you should repeat treatment after seven days to kill any lice that have hatched from eggs since the first application. Examples include the following: You can buy these products from pharmacies and supermarkets and your GP can also prescribe them. For them to work, you must follow the manufacturer's instructions to the letter. The above advice about making sure you apply enough insecticide to coat the hair and scalp also applies to these treatments.
Wet combing removes lice without using chemicals. It involves wetting the hair, applying conditioner, then combing it with a fine-toothed comb for at least 30 minutes every third or fourth day over a two-week period. The aim is to remove any live lice and eggs until none are left. A 2005 study found wet combing more effective than insecticides at curing head lice infestations. The Bug Busting kit used in the study is available on prescription. There are a number of herbal products such as tea tree oil and neem seed oil, and methods such as electric combs, which have been suggested as treatments for head lice. You can also buy sprays to prevent head lice. As yet, no good medical trials have shown that these treatments are effective. |
|||||||||||||||
|
|
|||||||||||||||
| Last updated 15.06.2011 |
|||||||||||||||
 |
|||||||||||||||
|
|
 |
|
|
| The materials in this web site are in no way intended to replace the professional medical care, advice, diagnosis or treatment of a doctor. The web site does not have answers to all problems. Answers to specific problems may not apply to everyone. If you notice medical symptoms or feel ill, you should consult your doctor - for further information see our Terms and conditions. |
|
© Copyright 1998-2011 NetDoctor.co.uk - All rights reserved |
