Head Lice

Algoma Public Health

Head Lice

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Don’t be alarmed.  Anyone can get head lice no matter how clean and careful they are.  If your child has head lice, there is no cause for alarm or embarrassment—head lice are a nuisance, but do not transmit disease, nor do they indicate poor hygiene or lack of cleanliness.


What to look for:

These tiny, flat insects have no wings, cannot jump or fly, but crawl very quickly.  Head lice live and breed on the scalp.  They are only 1-2 mm long, grayish-brown in colour, and hard to see.  Adult female lice produce many nits which may be easier to find than the actual bug.


Nits are very tiny eggs, half the size of a pinhead, oval in shape and gray to brown in colour.  After the eggs hatch, the nits casing are left behind and these are white in colour.  Nits look like dandruff but they are firmly glued to the hair and can’t be flicked off.  Inspect several hairs in different areas along the ears and hairline.  Nits can hatch 7-10 days after being laid.


In most cases, the first sign of a problem is itching and scratching of the scalp, particularly around the ears and the back of the head.  Sometimes there are no symptoms at all. Because other scalp conditions also cause itching, the best way to check for lice is to look for nits.  Act quickly if you find them.


How lice are spread:

Head lice are spread by direct head-to-head contact.  Heat produced by the body is required for head lice to survive and their eggs to hatch.  Lice cannot survive away from the body for more than 48 hours.


Treat lice and nits:

  • Read the product label very carefully.
  • Timing is important.  If the product is rinsed off too soon, lice and nits may not be killed.  If left on too long, you’re causing unneeded exposure to the lice-killing chemicals.
  • Rinsing a child’s hair under the tap (instead of a shower) will limit skin exposure and prevent the child from swallowing some of the product.
  • These products should not be used near the eyes, nose or mouth.  A towel held tightly over the eyes protects them during treatment.
  • When treating another person, wear plastic or rubber gloves to avoid unnecessary exposure to the product.


About the product(s):

All products are toxic and do not prevent head lice or nits.  Used for treatment purposes only.


Obtain a head lice shampoo, cream rinse or lotion from your drugstore.  You don’t need a prescription. Ask your pharmacist if you have any questions.  (Head lice products do not prevent lice.  Use them only when lice or nits are present).


If you are pregnant or breastfeeding and need treatment for lice, before choosing a product consult your physician or telephone the Motherisk Program at the Hospital for Sick Children in Toronto at (416) 813-6780.  If you are treating other people, wear plastic or rubber gloves.



  • For children under age 2.
  • For persons who are pregnant or breastfeeding.
  • If lice are discovered on eyebrows, eyelashes, or beard.
  • If the skin of the scalp is broken or infected.
  • If the person being treated has allergies to product ingredients.


When choosing a product, read the list of contents and the directions very carefully.  Don’t use a product if the person being treated is allergic to any of the ingredients.  In Ontario, the most common head lice products contain pyrethrins and permethrin.

  • Pyrethrins (e.g. R & C shampoo/conditioner) should not be used for anyone with a known allergy to ragweed, chrysanthemums, pyrethin or synthetic pyrethroids.
  • Permethrin (e.g. NIX Crème Rinse) should not be used for persons with a known allergy to chrysanthemums, synthetic pyrethroids, or pyrethrins.  Do not use on children under age 2 unless directed by a physician.
  • Isopropyl myristate 50% (Resultz) is an alternative treatment for use in individuals four years and older.
  • Suffocants (oil based products) this is an alternative treatment based on a recommendation by the Hospital for Sick Children in Toronto.  It can be used when two treatments with the above products are not effective, but not at the same time as the above products.  Call Algoma Public Health for more details or see recipe on our website www.algomapublichealth.com.
  • Sometimes head lice resist one product.  If live lice are found 24 hours after the first treatment, try another product and follow instructions on the product label.  If lice infestation persists, consult your doctor.
  • Store unused head lice products away from the reach of young children.
  • Wash your hands well, immediately after using a head lice product.
  • Treatment usually does not kill all nits.  Removing the nits after treatment in bright, natural light makes it easier to see any new infestations.
  • Usually a second treatment in 7-10 days is needed to kill any newly-hatched lice before they can lay eggs or transfer to a new head.  Follow the directions on the product label or check with a pharmacist.
  • Comb the hair to remove snarls, then take hold of a lock of hair.  Use your thumbnail against your finger to strip the nits from the hair starting from the roots right down to the tips. Place the nits in a bag.  Pin back that lock of hair and continue until all nits are removed. Try to remove the very tiny eggs laid right next to the scalp.
  • You can also comb out the nits holding a fine-tooth comb on a downward angle.  This is easier if a cream rinse is used after treatment but avoid after use of NIX.  Eggs very close to the head may need to be removed by hand.


Follow-up of close contacts is very important to prevent spread and protect your child from being re-infested.  Check the heads of all family members.  All affected persons should be treated at the same time.


You should also inform others such as the school, daycare centre, and parents of your children’s friends to prevent the spread and protect your child from being re-infested. Only those who are found to have head lice and/or nits are to be treated.



Extra house cleaning and use of insecticide sprays are not needed.  However, you will probably want to soak combs and brushes in hot water for 10 minutes.  Headgear, sheets, pillowcases, and towels should be machine washed in hot water.  The heat of the water or the hot cycle of your clothes dryer will kill any live lice and nits.



  • Check everyone that lives in your house and treat only those who have it.
  • Two treatments are usually needed a week apart.  Repeat the treatment only once. For the alternative oil & vinegar treatment, it may be repeated as necessary as side effects are unlikely
  • Removal of nits by hand/comb is necessary.
  • Head lice do not survive on dogs, cats or other animals.
  • Keeping hair short will not prevent head lice.
  • Check young school-age children regularly for head lice; more often if there is an outbreak.
  • During outbreaks, schools can plan activities so the head to head contact is reduced.  Coat hooks should be well spaced, if possible.
  • Discourage children from sharing hats, scarves, combs, hair accessories, helmets and pillows.


Date of Creation: June 1, 2015

Last Modified: June 1, 2015