The topic of head lice infestations (or pediculosis) is always relevant and of interest. Although the beginning of the school year is often associated with lice infestations, they can occur at any time of the year. In Canada, head lice are most common in school-aged children but can also affect adults. Contrary to popular belief, head lice are not related to poor hygiene, and can therefore affect anyone who comes into contact with lice.
Lice are tiny insects. In fact, they are considered parasites because they feed on human blood, much like mosquitoes. Lice, which reproduce very quickly, live at the surface of the skin, clinging to the host's hair shaft with their claws. Having lice is not a sign of poor hygiene. You can get rid of lice as long as you follow certain steps.
What do they look like?
Lice look like dandruff flakes or small, grey-coloured grains. However, because they are so tiny and move around very quickly, spotting adult lice is quite uncommon. What we usually see are lice eggs called "nits". A glue secreted by the lice allows the nits to remain attached to the hair, most often close to the scalp. Nits are pearl-grey in colour, are shaped like a tear and measure less than one millimetre (between the size of a pinhead and a sesame seed).
The primary symptom of a lice infestation is an itchy scalp, which may be more pronounced during the first 3 hours of sleep. The itching is caused by an allergic reaction due to repeated lice bites. It may take up to 4 to 6 weeks before itching develops and some people will not experience any symptoms.
If an infestation is suspected, it is very important that it be confirmed before starting treatment. Lice treatments must never be used as a preventive measure. Treatment should only be used when live lice are found.
Nits and head lice
Lice spread through direct contact with an infested person or, less often, by indirect contact with certain infested objects. Contrary to popular belief, lice cannot jump or fly. It is also important to note that lice do not live on pets.
There are actually three types of lice. What sets them apart is the size of their claws and the type of hair they cling to. Head lice are found in hair, behind the ears and on the nape of the neck (and can also be found on beards and eyebrows). They mainly spread through close head-to-head contact such as hugging or embracing, for example. It is easy to understand why children are most likely to get lice. Keeping long hair tied back is a simple and effective way to prevent lice from spreading. Although less likely, sharing personal items such as baseball caps, combs, headphones, pillows, stuffed animals and clothing can also contribute to spreading lice. However, head lice cannot live without a human host for more than three days which makes this type of indirect transmission less common.
Body lice attach their eggs to clothes. Infested clothing, towels and bedding facilitate the spread
of this type of lice. Body lice are also known to transmit disease.
The third type of lice are pubic lice, more commonly known as "crabs". They are found around the genitals and anus, under the armpits and can also be found on facial hair and eyebrows. Pubic lice are usually spread through sexual contact and, occasionally, when sharing clothing or bedding. Getting pubic lice from a toilet seat is highly unlikely.
Treatment involves the use of specially formulated head lice products that contain an insecticide. These products usually consist of shampoos, conditioners or sprays that are applied to the site of the infestation. Speak to your pharmacist, as he or she will be able to recommend a product that is safe and effective. In order to completely and successfully eradicate head lice, you must carefully follow the directions for use, as well as the pharmacist's recommendations. If an infestation is suspected, it is important that anyone who may have come into contact with the person in question be notified, so that treatment may be administered as soon as possible, but only if lice are confirmed.
When a child has lice, it is important to notify the school or daycare so parents can check and monitor their children. Contrary to popular belief, children do not need to stay home for any extended period of time. In fact, they can go back to school after the first treatment has been applied.
Treatment may fail and, in most cases, there is a valid reason. Here are the most common factors that lead to treatment failure:
If the eyebrows are infested, apply a thick layer of Vaseline at least twice a day, for about one week.
Visually inspecting the hair under a good light source is important. Remove nits after each application, then 2, 11 and 17 days after the first treatment. Here are the steps to follow:
A thorough inspection takes between 10 and 30 minutes.
To reduce the risk of reinfestation, the following measures are recommended:
Common home remedies such as mayonnaise, olive oil and margarine are not shown to be effective. They are not recommended at this time.
Remember: avoiding close contact, such as hugging individuals who are infested, is one of the best measures you can take to protect yourself from contracting lice. It is also important to teach children that they should not share combs, brushes, hats and scarves.
For more information:
Canadian Paediatric Society www.cps.ca
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.