Head lice are small, wingless, crawling insects that are commonly found on the human scalp. An adult louse is about 1-3mm in length and is a light tan or grey colour. Head lice survive in the hair by sucking the blood from the skin of the scalp. The female lice lay their eggs (also known as nits) on the hair shaft approximately 1-2cm from the scalp. Nits take about 7 days to hatch, then it takes another week for them to develop from nymphs into adult lice. Adult lice can survive about 30 days on the scalp but will not survive more than a few hours off the head.
Causes of Head Lice.
Anyone with hair can catch head lice, but they are extremely common in children aged between 4 and 11 years of age. This is most likely due to the close contact children of this age group have with each other while playing at school; especially young girls. Head lice are easily spread via direct hair to hair contact. Contrary to popular belief, head lice cannot hop, jump or swim from one scalp to another. There is no scientific evidence to support whether lice prefer clean or dirty hair; having head lice is not necessarily an indication of poor hygiene. It is rare, but possible to catch head lice from sharing hats, brushes or pillows.
Signs and Symptoms of Head Lice.
Head lice may not produce any obvious symptoms straight away, so if your child is regularly in contact with other children, it is best to do regular checks of the scalp. The most common symptom of live head lice is an itchy scalp. Sometimes you can see the live head lice on the scalp or hair. The eggs (nits) look like pale white specks stuck to the hair shaft and do not shift or fall out when the hair is shaken. Sometimes skin sores may also be present due to persistent scratching.
Diagnosis of Head Lice.
While head lice can live anywhere on the scalp the most common places they are found is behind the ears and at the back of the neck. A person is only diagnosed as having head lice if a living louse is found on the scalp. If only eggs are found, they are diagnosed as having nits. The easiest way to find lice and nits is to wet comb the hair from the scalp through to the ends. Cover the hair in conditioner and comb through the hair, sections at a time, using a fine toothed comb (a lice comb from the chemist is best). Go over each section of hair twice. While combing can also be done on dry hair, the hair conditioner makes it harder for the lice to cling to the hair and also slows them down, making them easier to catch and see on the comb.
Treatment of Head Lice.
Head lice can sometimes be eradicated by wet combing if it is done every day for up to 2 weeks until no head lice or nits are found. If the head lice are causing an itchy scalp late at night, this is also a great way of immediately removing the live lice that are causing the itching sensation. As an alternative to conditioner, products such as olive oil, tea tree oil or almond oil may also be used for wet combing. Electrified lice combs are available from some chemists, which kill the live lice by electrocution but do not destroy the eggs. The most common method for head lice removal is to kill them using either a medicated or natural head lice product from the local chemist. Speak to your pharmacist for advice on which head lice product is the best option for your situation. No single treatment is likely to remove and kill all the eggs, so it is recommended that a second treatment is administered 7-10 days after the first treatment, with wet combing performed every 1-2 days in-between.
Prevention of Head Lice
There is no sure fire way to prevent head lice. The best way to prevent spreading of head lice is to perform regular checks and treat any head lice or nits quickly before they have a chance to breed further. Chemists offer some head lice prevention products that you can spray onto the hair on a daily basis. It is also thought that head lice may be less inclined to cling to hair that is scented with eucalyptus, tea tree oil or hair spray. Keeping long hair tied back can also help by reducing the chance of hair to hair contact. While it is advisable not to share hats, hairbrushes, combs or pillows it is not necessary to wash everything excessively as the lice have a short life span (up to 3 hours at most) as soon as they leave the scalp.
For more information on the treatment of head lice and the use of head lice products, consult with your local pharmacist or doctor.