Head lice are small, wingless insects that can live on the human scalp within the hair. Their colour ranges from white to brownish, and when they first hatch they are so tiny that they are almost invisible to the human eye, although they can grow to just over a millimetre. Anyone can contract head lice, but they are very common in children.
It is a popular myth that head lice spread to other people by jumping from one head to another. In fact they cannot jump or fly, these parasites actually spread by climbing from the head or the hair of one person to the next. When children play together or work closely together at school, this makes it easy for the lice to spread, and this is the reason that the lice spread quickly between children. Head lice can only live on humans, so it is not possible to catch them from or pass them to animals and family pets. Common and conflicting myths that the lice will only target very dirty or very clean hair are also completely untrue; in fact hair length, condition and hygiene have no relevance whatsoever.
The life cycle of a louse
Eggs are laid by the female louse and are adhered to hairs, often at the roots. The eggs are difficult to see because they are so small. They hatch after 10 days, however the white eggshells will remain stuck to the hairs and it is these that are called nits. Head lice feed entirely on tiny amounts of human blood.
Once the lice have hatched they will take up to ten days to mature, when they will be able to breed for themselves and transfer to other people.
Detecting head lice
The main symptom of head lice is an itchy scalp, with a child scratching far more than usual. The itching is actually caused by an allergic reaction to the lice rather than by the lice moving about on the scalp, and this can take several weeks to develop. Some children may never develop an allergy, and will not experience itching so that the infestation will be harder to detect.
In some cases it will be possible to detect head lice by inspecting a child’s head for the presence of living, moving lice. If only the eggs or nits are found but no actual lice are seen then insecticide treatments should not be used, because the nits could be dead and left behind from a previous infestation, especially if the child has had lice before.
The most effective way to detect the presence of living lice is by using a specialist fine-tooth head lice comb, which will be available from pharmacies. The comb should have a spacing of 0.2 – 0.3mm between its teeth. Use the comb on wet hair and apply plenty of conditioner. Use a regular comb or brush first to detangle longer hair, as this will make the process less uncomfortable and help to protect hair from breakage. The head lice comb is designed to trap lice so check it after every stroke and wipe or rinse thoroughly in between strokes to remove any lice. Comb the hair in small sections and stroke downwards from the scalp to the ends. Use the comb several times on each section and be especially vigilant in the areas behind the ears and around the back of the neck. Continue until all of the hair has been combed.
If a child does have head lice, check the other members of the family in the same way in case the infestation has spread.
Head lice should be treated at home using either the wet combing method or with a lotion or spray that is specially designed to kill and remove head lice. There is usually no need to keep a child off school because they have lice once the treatment has commenced.
The wet combing method uses only hair conditioner and a head lice comb with a tooth spacing of 0.2-0.3mm. It involves thoroughly and methodically combing the hair to trap and remove the lice and their eggs. This can be time-consuming, however it is usually effective.
- Begin by washing hair as usual and apply plenty of conditioner. Some pharmacists may recommend a conditioner that contains tea tree oil, as it is thought that this may help to deter the lice, although it will not kill them.
- Use a wide-toothed comb or hairbrush to thoroughly detangle the hair. This needs to be washed before it is used again to prevent re-infestation.
- Take the fine-toothed head lice comb and place the teeth against the scalp at an angle, so that it effectively slots into the hair. Comb the hair in small sections, beginning at the scalp and continuing to the ends. Wipe or rinse the comb in between strokes. Comb the entire head systematically and go over each section at least three times. Rinse out the remaining conditioner at the end.
- This process should be repeated after three, six, nine, 12 and 15 days, so that any new lice that hatch in the meantime can be removed before they can breed.
Lotions or sprays
Recommended treatments for head lice have moved away from the traditional insecticides and many of the lotions or sprays that are used today do not contain harsh chemicals. A pharmacist will be able to give advice on an over-the-counter treatment or a GP may prescribe a specific preparation, especially if you have concerns or if a child or family member has allergies. They should only be used if living, moving lice are visibly present within the hair. It is essential to follow the instructions when applying the lotion, and two separate applications will usually be required. Most products are not known to kill unhatched lice or to destroy eggs, so inspect the hair again after five days and then again at ten days to check for newly hatched lice. Consult your GP if the product does not seem to have been effective. Also seek advice from a doctor or pharmacist if you are pregnant, if you need to treat a baby under 12 months old or if the child has allergies or asthma.
by Helena, mum to Amalia, Luca & Sofia