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Head Lice

How to Treat Head Lice

​​​​​​​​​​​​​​​​​​​​ head-lice


  • Anyone who has hair can get head lice—they’re not caused by being dirty. Head lice don’t spread illness or disease.
  • They’re spread mainly by touching heads with someone who has head lice. They can sometimes be spread by sharing items such as hats, hairbrushes, and combs that were used by someone who has head lice.
  • If 1 person in the family has lice, then someone else likely does too. It is important to check everyone in the family.
  • It’s a good idea for parents to check their younger school-aged children every week for head lice. See detection combing.
  • These tiny insects can cause a lot of stress and create a lot of work!

About Head Lice

  • Head lice
    • are tiny insects that can range from the size of a head of a pin up to about the size of a sesame seed (seeds found on a hamburger bun).
    • can vary in colour from tan, brown, dark grey, to greyish-white
    • crawl very quickly, which can make them hard to see. They don’t jump, fly, or swim.
    • live only on the human head and can make the scalp itchy. They’re found anywhere on the head, but especially behind the ears and the base of the scalp (neck area)
    • don’t live on and aren’t spread by family pets
  • Adult head lice lay about 8 eggs (called nits) every day. The nits are stuck to the hair near the scalp. They’re hard to see and can sometimes be mistaken for dandruff or hairspray droplets. After the nits hatch, their empty shell stays stuck to the hair.
  • You can’t get rid of lice with a hair brush or with a hair dryer.

Life Cycle of Head Lice

  • Only adult lice lay nits
  • Nits take between 7 and 10 days to hatch.
  • The lice become adults 6 to 10 days after they’ve hatched.

What is detection combing?

Detection combing is an organized way to look for lice and nits in the hair, from the scalp outwards. You may miss seeing the lice or nits if you only part the hair and look at the scalp.

How do I do detection combing?

You need:

  1. A plastic fine-toothed comb or plastic head louse detection comb (can buy in most drug stores)
  2. Good lighting (daylight is best)
  3. A regular comb


  1. Wash the hair well, dry it with a towel, then comb with a regular comb. The hair should be damp so it doesn’t become “fly away”, which can make it harder for the lice or nits to stick to the comb.
  2. Change to the fine-toothed comb. Start on one side of the head. Use your fingers to part the hair. Place the comb at the top of the head, with the teeth touching the skin of the scalp. Keeping the comb in contact with the scalp as long as possible, slowly pull the comb carefully towards the end of the hair. For long or thick hair, it might be helpful to clip the hair in several sections and thoroughly comb through 1 section at a time.
  3. Look closely at the teeth of the comb. Wipe the fine-toothed comb on white tissue or paper towel after each stroke. Look on the tissue and the comb to see if there are any live lice (A magnifying glass may help).
  4. Rinse the comb in a sink or bowl of warm water after every stroke, then wipe dry.
  5. Comb over and over again from the top of the head to the ends of the hair in all directions, until you’ve worked around the entire head. It should take 10 to 15 minutes, depending how long the hair is.
  6. When you’re done, clean the combs and clips well under running water. Put the tissue you used to clean the combs in the garbage right away. If you find a louse or nits, see “Washing Items” for how to clean the combs and clips.
  7. How do I know if I need to treat my child?

    When you do detection combing every 3 to 4 days and you:

    ​​ Find a live louse Find only nits (eggs)Find nothing after 12 days
    • treat hair with an approved product
    • keep detection combing every 3 to 4 days for 12 days
    • treat the hair if you find a live louse
    • don't treat

    If you do 1 detection comb and don’t find nits or a live louse, you don’t have to check again until your regular weekly check.

    If you find something in the hair while combing and aren’t sure what it is, stick it on a piece of paper or clear sticky tape and show it to your public health nurse or family doctor. There may be other things in the hair that aren’t lice.

    Treating Head Lice

    Only treat when you find live head lice. If you have questions, ask the pharmacist.

    Head lice shampoos, cream rinses, and sprays have been tested and are safe and effective treatments for head lice. You can buy them at any pharmacy and don’t need a prescription. If you’re not sure which one is best for your needs, speak with the pharmacist.

    Read and follow the directions on the head lice shampoo, cream rinse, or spray.

    If the treatment’s going to work, you must follow the instructions exactly (including if the hair has to be wet or dry and when to treat a second time).

    You may have to buy more of the same product if you have to use it on longer hair.

    It’s important to use the correct amount of product each time. Using less of the product to make it go further will mean that the lice survive and more treatments will be needed.

    Killing Live Head Lice

    The shampoo, cream rinse, or spray kills the live lice on the head but may not kill the nits.

    While the nits don’t need to be removed from the hair, some people use a comb to remove nits after using lice treatment because they don’t like the look of nits in the hair.

    A second treatment with head lice shampoo, cream rinse, or spray is almost always needed 7 to 10 days after the first treatment to kill newly hatched lice. If you’re not sure if a second treatment is needed, speak with your pharmacist.

    Washing Items

    Wash any items that were in contact with the head of the person who has lice (e.g., combs, brushes, bedding, hats).

    • Washable items can be machine washed, soaked in hot water, or placed in the dryer on hot heat.
    • Put non-washable items in a sealed plastic bag for 2 weeks. Lice can’t live this long away from the human head.

    To learn more about how to check for and manage head lice please view the AHS head lice video.


    How can I learn more?

    To learn more about head lice, you can:

    • speak with your pharmacist or family doctor
    • visit your public health office
    • call Health Link at 811​

Current as of: May 7, 2019

Author: Public Health, Alberta Health Services