Lice transmission and treatment

What are lice?

Lice are tiny (1 to 3 mm long) insects that are greyish white (or reddish brown after they have fed) and that live near the hair roots. They can also live in the eyebrows or in beards. Every day, they lay approximately 5 nits (lice eggs), which hatch after approximately 10 days. Live nits are light grey and are approximately 1 mm long. They look like swollen dandruff or sesame seeds. They generally attach to the hair less than 6 cm from the scalp. And since they cling to the hair, they are difficult to remove.

Lice are parasites that feed on the blood of their human host. They bite the scalp and inject their saliva, which can cause itching and small red sores near the ears and the nape of the neck. Itching can start from 4 to 6 weeks after infestation.

Head scratching is often a sign of a lice infestation, but you can only be sure  with a visual inspection. Finding nits doesn’t mean you have lice, as inactive or empty nits  can stay in the hair even after lice have been treated. A visual inspection is done by going through the hair with a fine-toothed comb.

Myths about lice

Remember that head lice:

• Do not discriminate: They attack clean hair and dirty hair. They also infest people from all walks of life.
• They don’t spread disease.
• Lice are different from the fleas that live on animals.
• They don't jump or fly.

How do lice spread?

Lice move very quickly from the head of an infested person to someone else through direct contact. Children can easily catch lice, as they often do activities with their heads close together and give each other hugs. Schools and daycares are places were lice get spread a lot.

Lice can only survive for 2 to 3 days if they aren’t in contact with a human being. They don’t spread as easily through contact with personal items (e.g., hats, combs, hair brushes, pillow cases, etc.). However, nits can live for up to 10 days away from the human body.

If you receive a notice from your school or day care service asking you to check your child’s head, don't take this lightly. Quick screening and treatment will prevent lice from spreading to family members and other people.

How to avoid getting lice

Lice are resistant to ordinary shampoos, and no treatment can prevent a lice infestation. However, there are things you can do to prevent lice:

• Children with long hair should keep it tied back.
• Remind them to avoid putting their head against the head of a friend (when reading or giving hugs).
• Tell them to put toques, hats and scarves inside the sleeve of their coats in their locker at school.
• Remind them not to share hair brushes, hair elastics, headbands, toques or hats with their friends.

How to check if your child has head lice

Regularly check your child’s hair and scalp with a fine-toothed comb (a special lice comb). Check for lice:

• At least once a week, when children wash their hair, and especially at the beginning of the school year.
• Every day if lice have been found on a family member.
• If your child is scratching his or her head or complains of an itchy scalp.

To check your child’s head, make sure you have good light. A magnifying glass can also help. Wet the hair before checking it. You can use conditioner, as this helps with combing and can soften any nits that may be in the hair.

Look for lice and nits particularly behind the ears and near the nape of the neck. Start with the nape and ears and divide the hair into sections about the width of the comb. Check the hair one section at a time by running the comb from the scalp to the hair tips. After running through each section, check the comb for nits or lice. Once you finish checking, don’t forget to wash your hands.

It’s easy to confuse nits with dandruff, dead scalp skin, dust or dirt. The difference is that nits cling to the hair, and you sometimes have to remove them with your nails or tweezers.

If you find live lice or nits on your child’s head, you must treat them.

How to get rid of lice

Head lice treatment

If you find live lice:

• Right away, apply a lice treatment, which is a special lice insecticide (or pediculicide) that you can get from your pharmacy. These products are available as shampoos, rinses  or sprays. Your pharmacist will recommend the best treatment for you or your child and give you all the information you need to ensure the treatment is effective. Your pharmacist can help you chose a product over the counter, and in some provinces, can even prescribe you a treatment against lice. Children under 2, pregnant or breastfeeding women, and people with allergies to the ingredients in these products should consult a pharmacist or doctor to ensure they are using a safe treatment that is right for them.
• Notify your school or daycare as well as anyone who has come into close contact with the infested person.
• Keep your child home from school or daycare until you’ve applied the treatment. Your child can go back once the first treatment has been applied.
• Once you've applied the treatment, remove the nits with the lice comb, which you should dip in hot water after each comb stroke. Any nits that won’t comb out can be removed by dragging them down the hair shaft with your nails or tweezers. Slowly removing nits with a lice comb greatly increases the chances that the treatment will work.
• Check all other family members and treat everyone the same day. Only treat people who are infested, as preventive treatment is unnecessary and may create treatment resistance.
• Remove the nits with each treatment and on days 2, 11 and 17 after the start of treatment. In the following days, use a lice comb to check all other family members for infestation as well. Apply a treatment as soon as you find live lice.
• If you find live lice within 24 to 48 hours after the first treatment, do another treatment with another type of product. Your pharmacist can help you choose another option that's best for you.
• Repeat the treatment 7 or 9 days after the first application (depending on the product used), whether or not you find live lice or nits.
• See your pharmacist again if the treatment doesn’t work.

When treatment doesn’t work

Lice treatment may not work for various reasons:

• You didn’t follow the product instructions:
  • You applied the product to dry instead of damp hair.
  • You didn’t leave the product on the hair long enough.
  • You didn’t reapply the treatment at the right time.
• You used a conditioner (which is contraindicated for certain products).
• The person has been reinfested.
• The lice are resistant to the product. Microbes and parasites can adapt and become resistant to existing treatments. This is particularly true for lice, which considerably reduces treatment choices and has a negative impact on public health.

Home lice remedies

Some people suggest using fatty substances, such as petroleum jelly , mayonnaise, olive oil or margarine, to “suffocate” the lice. Although these products can make it harder for lice to breathe, no study has demonstrated that they actually kill lice. Vinegar and lavender are other popular home remedies, but no study has demonstrated their benefits. No data indicates that hair dye is effective at getting rid of lice.

Cleaning personal items

Clean all personal items that come into contact with hair, such as caps, hats, combs, hair brushes, accessories and toys used on a regular basis. You should also wash any clothing, pillow cases, bed sheets and towels used in the previous 2 days.

Depending on the item, choose the cleaning method that is best suited:

• Soak objects in a lice shampoo (undiluted) for 5 to 10 minutes.
• Soak objects in warm water (approximately 65 °C or 150 °F) for 5 to 10 minutes.
• Put clothes in the dryer on high for 20 minutes.
• Have clothes dry cleaned.
• Store items that can't be washed or put in the dryer in a sealed plastic bag for 10 days.

Furniture, floors and items that can’t be washed (e.g., armchairs, stuffed animals, carpets) must be vacuumed, and the vacuum cleaner bag must be thrown out. Insecticide sprays are strongly discouraged. These products are ineffective for lice infestations and can pose a major health risk for people and animals exposed to these potentially toxic products.

For more information about how to treat and clean objects that have been in contact with your child, don't hesitate to consult your pharmacist.