There are many parents who have experienced a sinking feeling as they comb their child's hair and see the telltale sign of nits.

Unfortunately, the first sign there is a problem is when the child starts scratching his or her head -

by which time the infestation is well established.

But staff at South Downs Health NHS Trust, which is responsiblity for community and mental health services in the Brighton and Hove area, say there is nothing to be embarrassed about and the problem can be quickly solved.

The head louse is a tiny insect that lives on the hair.

The adult lays its eggs, which are known as nits, at the roots of hair to which they become firmly attached.

It takes two weeks for the eggs to hatch and the lice then bite into the scalp to get blood. It is this which causes the itchiness.

A child can catch lice after just a moment's contact with another child or adult who is already infected and, despite popular belief, adults are just as likely to catch them as children.

Head lice are often wrongly thought to be a sign of poor hygiene, which is why people get embarrassed about them. But lice can live on any kind of hair, whether dirty or clean.

The usual symptoms are an itchy scalp and tiny, pearly-white eggs covering the roots of the hair.

Ann Garmston of South Downs Health says regular checks can help keep any problems under control.

She said: "It is the parent's responsibility to regularly check their child for head lice and to notify the school of any cases of infection."

"There are plenty of special shampoos and insecticidal treatments available from pharmacies which can clear up the problem.

"There is no particular time of year when head lice are more common. They can happen at any time."

Detection combing is a recommended way to confirm cases of infection before treatment.

Proper diagnosis is important as many people start to experience itching when they hear of head lice in the community, even though they don't have the infection.

To check for lice, wash hair well and towel dry. The hair should be damp but not dripping.

Comb through the hair thoroughly, first with an ordinary comb to remove tangles then using a special plastic detection comb bought from the pharmacist.

Start with the teeth of the comb touching the skin of the scalp at the top of the head. Keeping the teeth of comb in contact with scalp as long as possible, comb slowly towards the end of the hair then look carefully at the teeth of comb for signs of infection.

The process should be repeated for ten to 15 minutes, covering the scalp and hair in all directions.

Head lice are small, greyish-

brown wingless insects no bigger than a sesame seed, even when fully grown.

Treatment with an insecticide should only be given if live lice are seen on the comb or on a tissue used to clean it.

Ms Garmston said: "Many people think their child can only catch lice at school but this is not so and regular checks are vital. It happens when heads are in close contact with each other for a period of time."

Lice cannot fly, hop or jump so they are unlikely to be picked up from brief contact with other people.

Once lice are discovered, everyone in the home should be checked.

Regular use of a lotion should clear up the infestation after about two weeks. If they continue after that, further advice should be sought from a GP or pharmacist.

Many people are unhappy about using insecticidal treatments and concerns have been raised about the prescription lotion Carbaryl and those containing the organophosphate Malathion.

Head lice can also develop resistance to repeated treatments, rendering them ineffectual.

Suggestions for natural alternatives include tea tree shampoo. Homeopathic medicine experts say this can have an effect as lice do not like its smell.

Another product called Aromaclear, made from a blend of essential oils, makes the head an inhospitable place for head lice. It also has a pleasant fragrance.