Headlice

What are the symptoms of this condition?

A head louse infection may cause itching and irritation of the scalp, which leads on to scratching, although these symptoms are not always present. 'Nits' (the empty egg cases of the louse) may be seen adhering to the hair shafts; they can be mistaken for dandruff but, unlike dandruff scales, cannot be easily brushed off the hair.

Head lice do not transmit or carry any infectious diseases. Contrary to popular belief, infection with head lice is not an indicator of poor hygiene; it can happen to adults as well as children, and to people with short hair as well as those with long hair.

What is the cause of the condition?

Head lice, small parasitic insects which live on the scalp, need the warmth of the scalp to survive and will feed on blood which they suck up through the skin; they are rarely found in eyebrows or eyelashes. The female louse attaches its eggs to the shaft of a hair very close to the scalp. Eggs are fastened to the hair with a glue-like substance that makes the eggs resistant to removal by the normal process of hair washing. Each egg will hatch in around seven days, and it is possible to estimate the duration of an infection by measuring how far the nits have moved from the base of the scalp, where they were first attached to the hair. Hair grows at around 5 millimetres per week (half a centimetre), so any nits that are found at a greater distance from the scalp are likely to have already hatched (they are over seven days old). If the hair shafts are clear of nits from the scalp up to approximately five millimetres away, this should imply that there are no lice still living in the hair.

An infection must be confirmed by the presence of living, moving lice. Although nits may be present, they may be empty shells and this does not prove that the infection is active. Although they are very small (between 2 and 4 millimetres long), the lice are visible to the naked eye and can be detected by careful combing with a nit comb. Head lice are only transmitted by direct head-to-head contact; they cannot fly, jump, or swim, and are unable to survive after a very short time away from the human host.

Because head lice can only be passed on through close contact, outbreaks are common in schools, and in family groups, where head-to-head contact is more likely.

What complications might occur?

In most instances the infection can be treated successfully using non-prescription preparations, and does not lead to any further complications.

What can I do to treat myself?

Re-infection after treatment is a common problem, and can largely be overcome by careful tracing and follow-up of all persons with whom the subject has had close contact over the previous month. All those who are found to be infected should be treated with the same treatment, ideally at the same time.

Because of the growing problem of insect resistance to the liquids and lotions that are available for the treatment of head lice infections, it's very important that you are sure there is an infection before proceeding. Although the lice are visible to the naked eye, the best way of detecting lice is to use a fine-toothed detector comb; take a small section of scalp at a time, drawing the comb through the hair from the scalp to the hair end. The comb should then be wiped on a tissue. Any lice trapped in the teeth of the comb will be seen on the tissue paper. This procedure is repeated until the whole head has been combed; if any live lice are found this indicates the presence of an infection.

As infections are often spread to a family from a child of school age, regular inspections of children's hair is very important.

The current guidance for the treatment of head lice infections is called the 'mosaic' approach. Just those with the infection should be treated, and not the whole family; using one of the common insecticide preparations (more details of which can be found below), apply to the hair in the way recommended by the manufacturer, which can involve leaving a lotion or a liquid on the hair for at least 12 hours or overnight. This should be repeated after 7 days as a matter of routine, so that any lice which have emerged from eggs in the meantime will be killed. If this fails, contact the pharmacist or your doctor for further advice, which will commonly be to apply a different insecticide preparation in the same way. Further courses are not considered suitable and medical advice should be sought if two insecticide courses are unsuccessful.

For advice on the most appropriate treatment, consult the Pharmacy2U pharmacist.

It's very important that head lice treatments are only used when there is a definite infection - they must not be used as a preventative measure, or if you are not sure if there is an infection or not. There is only one product which is licensed for the prevention of head lice, called Rappell, which should be sprayed onto the hair each morning when an infection is likely.

Alternatively, head lice infections can be managed using a mechanical approach. Wet combing is a natural and popular way to clear the hair of lice, and involves washing and conditioning the hair and using a fine-toothed comb from the root to the tip of the hair, as before, until all the lice have been physically removed. This 'bug busting' technique should be performed every 3-4 days for at least 2 weeks, and repeated if further live lice are detected. This approach takes considerable motivation, and it has not been confirmed as being as effective as using insecticidal preparations. Also available is an electric comb, which should be used on clean dry hair, and kills lice by means of a small electric discharge whilst combing.

What treatments are available for me to purchase?

The use of insecticides is discussed in detail in the previous section. Many preparations are available as lotions and liquids; lotions contain an alcohol that can irritate the scalp, and may trigger asthmatic symptoms in susceptible people, and so should not be used in asthmatics or those with a sensitive scalp. Other preparations are available in a crème rinse, and a mousse; while shampoos have been popular in the past, their use is no longer recommended, as they are not in contact with the hair for long enough to be very effective.

There is also a repellent spray available (Rappell) which may be used as a preventative measure, when there is no infection present; it's sprayed into the hair each morning to prevent an infection when this is likely.

To view the full range of head lice treatments available from Pharmacy2U click here.

What treatments are available from my doctor?

If the treatment advice above is not sufficient to treat an infection, your pharmacist or doctor will ensure that you have been applying the preparation in the correct manner. Whilst the most common treatments are all available without a prescription, you should talk to your doctor if the infection persists.

What additional investigations might be needed?

A positive identification of head lice is very important before using any insecticides; it is unlikely that any additional investigations will be needed.

Any other information I should have?

Head lice are a common problem, however with care, and attention to the measures outlined above, infections can be controlled and removed safely and effectively.