Lice are tiny greyish insects. They are about the size of a sesame seed and barely visible to the naked eye. They live on the scalp, close to the root of the hair, and sometimes on eyebrows and in beards. They do not jump or fly. Adult lice live about 20 to 30 days.

Lice are irritating but not dangerous. They do not spread diseases and are not the result of poor personal hygiene. Lice are most common in children in a school or day care setting.


Lice lay eggs called nits. Nits stick to hair strands and are difficult to remove. Live nits are a greyish white colour and look a bit like transparent, oily and swollen dandruff. They are usually located within 6 mm of the scalp and take 7 to 12 days to hatch.

Dead nits are white in colour and dry. They are most often located more than 6 mm from the scalp.


An itchy scalp is the main symptom of lice. The itchiness is caused by an allergic reaction to the saliva that the insect injects in the scalp to feed on blood. However, some people with lice do not have itching. An inspection of the head is the best way to find lice or nits. As they’re generally less than 10 to 20 live lice on the head, it is extremely important to conduct a thorough inspection. 

Inspecting the head for lice


  • at least once a week, after washing hair, especially during the back-to-school period;
  • every day if those around you have lice;
  • when you have an itchy scalp.

Good lighting is important in order to see lice moving because they run from light. Get a fine-tooth comb for that purpose (available at the pharmacy) and, if possible, a magnifying glass. Wet the hair to make it easier to part with the fine tooth comb.

To inspect the head:

  • Part the hair into thin sections about the width of the nit comb. If the hair is very long, split in 2 cm locks.
  • Comb the hair from the roots close to the scalp and through to the tips, one section at a time.
  • Inspect the hair by sections from one side of the scalp to the other, and from the hairline to the back of the neck, paying particular attention to the back of the ears and to the neck.
  • With each stroke of the comb, check for lice or nits on the fine tooth comb.
  • Don’t forget to wash your hands after each inspection.

What to do if you have lice or nits?

  • Consult a pharmacist as soon as possible to get a prescription for the most appropriate anti-louse treatment.
  • Apply the head lice treatments as soon as possible.
  • Notify the school, the daycare and anyone in direct contact with the infested person. Generally, children should not be excluded from school or daycare.
  • Inspect the heads of all family members.
  • Treat ONLY those who have lice or live nits.

Treatment is most effective if everyone with lice or live nits is treated on the same day. It may be difficult to determine whether the nits are dead or alive. If in doubt, consult a healthcare professional before starting treatment.


The person who has lice and live nits must be treated quickly with a product that treats lice.

There is no treatment for the prevention of lice, which means that there is no use in treating people with neither lice nor live nits.

Treatment is most effective if everyone with lice or live nits is treated on the same day. It may be difficult to determine whether the nits are dead or alive. If in doubt, consult a healthcare professional before starting treatment.

Hair treatments

Lice and nits resist ordinary shampoos but can be eliminated with special over-the-counter treatment. It’s important to apply one of the recommended treatments as soon as you discover lice or live nits on your head.

Choosing the right product

Although pediculicides are sold over the counter, you should consult a pharmacist who will know which treatment is appropriate.

Some treatments can be used by people who are pregnant or breastfeeding. However, it is best to consult a doctor or pharmacist before using a pediculicide.

If the eyebrows are affected, apply petroleum jelly Vaseline® ou Lacri-lube®) 2 to 4 times a day for 1 week. Afterward, dead nits can be removed with your nails or tweezers by sliding them down the hair shaft.

It is strongly discouraged to use products for pets.


Depending on the treatment used, the product must be applied 2 or 3 times, within a specific time frame that your pharmacist will explain to you. All the recommended treatments must be administered, even if you no longer see live lice or viable nits in the hair. To increase chances of success, it is recommended that you also use a fine-tooth comb to remove the lice and nits during treatment.

Apply the product by following the manufacturer’s instructions. Then dry the hair using a clean towel or hairdryer.

Application of anti-louse products may cause redness or irritation of the scalp.

You must also inspect the head and remove lice and nits with a fine comb on the second, eleventh and seventeenth day after first application of treatment. See the Inspecting the head for lice and Removing nits sections for further instructions.

Live lice 17 days after starting of the treatment

If live lice are found 17 days after the product was first applied, or there are doubts about the effectiveness of the treatment, consult a doctor, pharmacist or nurse, or contact Info-Santé 811 so that a health professional can assess the situation and tell you what steps to take to get rid of the lice. Treatment might fail because the treatment schedule was not followed (ex., instructions or recommended number of applications not followed) or the lice might be resistant to the type of product used. It might also be a new infestation.

Removing nits

After the use of anti-louse treatment, it is important to remove live nits from the hair in order to avoid the hatching of new lice.

To remove the nits more easily, apply a humid towel to the scalp for at least 30 minutes. Then untangle your hair with a comb.

Make sure you have a fine comb, good lighting and have easy access to hot water so that you can rinse the comb with each comb-through. If possible, also use a magnifying glass to help you.

To remove nits:

  • Part the hair into thin sections about the width of the fine comb. If the hair is very long, split in 2 cm locks
  • Comb through each section of the hair.
  • Incline the fine-tooth comb toward the scalp and comb the section of hair as close as possible to the scalp.
  • Ensure that the teeth of the fine-tooth comb have gone all the way through the hair section.
  • Slide the fine-tooth comb from the scalp to the end of the hair section.
  • Inspect the hair one section at a time, from one side of the head to the other, and from the front of the head to the nape of the neck, paying particular attention to the area behind the ears and the nape of the neck.
  • Rinse the fine-tooth comb with hot water after every stroke.

To remove the nits that can’t be combed out, use your nails or tweezers to slide them down the hair shaft.

The fine tooth comb and ordinary comb must be cleaned immediately after use. See the Cleaning personal effects section below to find out how.

Don't forget to wash your hands when finished removing nits.

Removing nits and using anti-louse treatment increase your chances of getting rid of lice and nits.

Eyebrow treatment

If you find lice or nits on the eyebrows, apply a thick coat of petroleum jelly (Vaseline® or Lacri-lube®). This stops the lice from moving and suffocates nits, preventing them from hatching. Remove the lice and nits with your nails or tweezers. Repeat procedure 2 to 4 times over the course of a week.

Cleaning personal effects

It is unlikely that lice is transmitted through personal effects (bedding, combs, hairbrushes, hats, caps, etc.). However, you can treat these objects as follows:

  • Soak personal effects in  undiluted anti-louse shampoo for 5 to 10 minutes
  • Soak  personal effects in hot water with a temperature of about 65 ˚C for 5 to 10 minutes
  • Put clothing items in dryer on hot setting for 20 minutes
  • Dry clean the clothes
  • Store personnel effects in an airtight plastic bag for 10 days, which is the average time for nits to hatch

Use a vacuum to clean carpets and sofas.

It is strongly discouraged that you spray your house or furniture with insecticide. Insecticides are not only ineffective in eliminating lice, they can also be harmful to your health and that of your pets.

Protection and prevention

There are no prevention treatments for lice. However, it is possible to limit or avoid the spread of them by identifying and promptly treating people with lice. If you or anyone in your family gets lice, immediately tell everyone with whom you have been in direct contact, including your children’s school or day-care staff. This way, others that may have caught lice are quickly identified and treated.


  • Attach long hair
  • Remind children to:
    • Avoid coming into head to head contact
    • Store their hats, caps or scarves in the sleeves of their coat
    • Not to share personal effects such as combs, brushes and hats
  • Regularly inspect the heads of everyone in your family with a nit comb:
    • At least once a week after washing hair, especially during back-to-school period
    • Daily if someone in the surrounding has lice
    • As soon as there is a case of itchy scalp

People at risk

Everyone can get lice. Lice are not the result of poor personal hygiene and are common in school or day care setting, especially during back-to-school period.

Anyone in direct contact with someone who has lice stands more risk of getting them too.