HEADLICE

What are Head Lice ?

Lice are small (about 5 millimetres long) wingless insects of which three types cause disease in man: the head louse, the body louse and the crab or pubic louse. These insects feed by sucking blood from the skin. Head lice live close to the scalp for warmth, moisture and food. For female lice it is a place to lay eggs. Head lice are common in children. The lice pass from one person to another usually by direct head to head contact. The infected patient, usually a child, is seen scratching his head because of itching. However in many children, it causes no symptoms. The scalp becomes red and shows scratch marks. The female louse lays around 10 eggs each day. The empty egg cases or nits may be seen attached to the hair usually behind the ear. Look for nits in the scalp particularly behind the ears or on the neck. They look like white or grey pips that are quite firmly stuck to the hair. Alternatively, they can be found by using a plastic detection comb on damp hair.

How do Head Lice occur ?

The parasite causes inflammation by feeding on the scalp or skin. Scratching causes bacteria to further infect the inflamed site.

Why do Head Lice occur ?

Head lice affect all social classes equally. They do not occur more frequently in people with dirty hair, contrary to popular belief. They will live on clean or dirty hair. Children usually get infected if there are head lice at school. They may pass the infection on to the rest of the family.

Treatment Involved for Head Lice

A “Bug Buster” kit can be obtained from the chemist. This consists of a special detection comb and conditioner. The comb is used on hair that is shampooed with the hair conditioner. Combing is carried out usually for about 20 to 30 minutes every fourth day for at least two weeks. If lice are found at each combing session, the period time is extended to another four days. This is a simple if laborious approach. An alternative method is to use an insecticide. A wide variety of special lotions and shampoos are available from chemists for the treatment of head lice. These may contain permethrin, malathion or carbaryl. There have been some concerns that carbaryl may cause cancer in rats. Most experts believe that this risk is not real in humans because the application is so small and only to the skin. Nevertheless, it is probably best to reserve carbaryl for lice not responding to other treatments. Alcohol based preparations should be avoided in small children and in those who have asthma. Each preparation has its own particular instructions: follow them carefully. A second application after seven days is usually recommended. Unfortunately many lice have become resistant to the insecticides (i.e. they don’t work).

During Treatment for Head Lice

The infection may reoccur if the patient is exposed to another infected person. All members of the family should be checked for lice. Don’t assume if they do not have an itchy scalp that they do not have lice. Many who have lice may not be itchy. Only those who have lice need treatment. Scratching may cause bacteria to enter the skin and infect the inflamed area. If this happens, the affected skin will become weepy and perhaps sticky. The doctor may prescribe chlorhexidine to put on the scalp, or antibiotics if it is severe.

After Treatment for Head Lice

Look for nits in a child's hair regularly, especially if head lice are known to be infecting others at school.

If Head Lice are Left Untreated

The infection itself is harmless. The itching would continue, upsetting the child, and increasing the risk of infecting others, both at school and at home.

Effects on Family of Head Lice

A child may bring head lice from school and infect the family. This is so common that if a child is affected, the whole family must be treated. This will also make it less likely for the child to be reinfected after a course of treatment.