Learn how to check for and treat head lice.
What are head lice?
Head lice are parasites that only infect human scalps. They are spread by head to head contact but do not cause disease. They do affect the health of our children through cost to families for treatment, frustration, unnecessary embarrassment and sometimes education time lost.
- Lice love clean human hair.
- Lice do not jump or fly, and their bites make the scalp itchy.
- Nits are lice eggs, which are attached to the hair, close to the scalp. They are as tiny as dandruff or about 1/3 the size of a sesame seed.
- You can't get rid of nits by brushing, or with a hair dryer.
- After the head lice hatch, the shell of the nit stays stuck to the hair. If it is more than 12 mm (1/2 inch) away from the scalp, it is probably empty.
- Lice are spread by head-to-head contact and by sharing brushes, hats or other items that come in contact with the head.
- Head lice are common where children play or work closely together.
- Lice do not cause disease.
- Adult head lice lay about 10 eggs (called nits) every day. These nits are stuck to the hair near the scalp.
- It takes 7-10 days for the nits to hatch. It takes 6-10 days for lice to become adult. During that time, it stays on the head, but does not lay.
How do I prevent my child from contracting head lice?
- Teach your child to not share hats, brushes, helmets, hair barrettes and towels.
- Keep long hair tied back when lice have been identified in your school.
Find more information on head lice.
What do I need to know if my child or student has head lice?
- Head lice are an ongoing problem but are not a major public health concern as they do not spread disease. They can be a community concern because of the nuisance and discomfort surrounding infestations and spread.
- The primary responsibility for control of head lice rests with the family and community, though trained volunteers can help families by providing routine head lice screening and parent education. Public health nurses can also answer questions about the management of head lice.
- Please note that public health nurses do not perform head lice checks for children and families at any public health units. Nor do public health nurses visit schools to conduct head lice checks on students when there is a concern or case.
- If a child has head lice they can continue to have contact with others for the remainder of the day - children should not be excluded from the community or school due to head lice. If there are problems with the treatment, parents are encouraged to consult a public health nurse for information and resources. To prevent the spread of head lice and ensure that the child has received treatment, information letters should be given to parents and classroom contacts. Download a sample parent and classroom letter.
How do I check for head lice?
To check for head lice, you will need:
- A bright light
- A metal lice comb (optional)
- A regular comb
- Hair clips for longer hair
- Paper towels
Then follow these steps:
- Explain to your child/family member what you are going to do. Have them sit in a comfortable spot under bright light.
- Untangle long hair using a regular comb. Divide the hair into four sections and check one section at a time.
- You are looking for live lice and nits. Nits are the lice eggs that cement to the hair near the scalp. Nits are white, grey or yellowish and can be confused with fluff, dandruff or dirt however a nit will not move until you dislodge it.
- If using a lice comb, comb it through the hair close to the scalp and then wipe on a paper towel. Look at the paper towel for lice or nits.
- You must look through the entire head. Use hair clips to hold longer hair in place.
- If you find lice or nits follow the instructions in the treatment options section of this resource.
Check the heads of all family members for lice and nits as they are easily spread. Treat all infested family members at the same time otherwise you may not rid your house of the lice and the infestation will continue despite the treatments given.
What are the approved treatment options for cases of head lice?
There are only two acceptable treatment options:
- Option A: Head lice shampoo - special head lice shampoos or rinses are used because they have been tested and determined to be a safe and effective treatment.
- Option B: Wet-combing - a non-chemical way to find and eliminate head lice.
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Option A: Head lice shampoo
Special head lice shampoos or rinses are used because they have been tested and determined to be a safe and effective treatment
Steps to follow
Do Remember
Apply lice shampoo to dry hair. Treat all infested family members at the same time. Read directions carefully.
Unless you treat all infested family members, head lice can be passed on from one person to another when heads touch.
Remove all nits by gently using a metal "nit" comb or use your fingers to pull nits from the single strands of hair.
Metal nit combs are available at your local pharmacy. If it tugs the hair, it may be upside down. Place lice/nits in a bowl of hot soapy water. Flush down the toilet when done.
If live, active lice are seen 24 to 48 hours after the first treatment, resistance or a heavy infestation should be suspected. Immediate treatment is recommended using a different product, followed by a second treatment seven days later.
The medications should be kept out of the reach of young children. These medications cannot be used for infants. Pregnant or nursing mothers should only use head lice medications following advice from their doctor.
Apply lice shampoo a second time 7 to 10 days after the first shampoo. Repeat step 2.
A second shampoo will make sure that any head lice which hatch after the first shampoo will be killed before they have a chance to lay any eggs.Two shampoos and a follow-up head check with nit removal is the best way to make sure head lice are gone.
If live head lice or new nits are found, try Option B. Consult a Public Health Nurse if you have any questions.
Wet combing breaks the life cycle of head lice by removing them before they are grown and able to reproduce.
After treatment checklist
- Wash all bedding, towels and clothes used in the past two to three days in hot water, including those worn during treatment.
- Launder all washable clothing, bedding, and towels in small loads with hot water and/or put in hot dryer for 20 minutes.
- Wash hair brushes, combs and hair accessories (barrettes, ribbons, etc) with hot soapy water.
- Anything that can't be washed (such as blankets, coats, headwear, stuffed toys) can be treated by placing in a closed plastic bag for 10 days or putting in a hot dryer for 20 minutes or putting in the freezer for 48 hours or ironing it.
- There is no evidence that a major cleaning of the house is needed to get rid of head lice. Only items that have been in direct contact with the affected person(s) need to be washed.
- Repeat treatment according to option chosen.
- Notify those in contact with child that lice/nits were found, such as school, Brownies, Scouts, sports teams, friends.
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Option B: Wet-combing
Option B: Wet combing method: Remove the lice
Wet combing is based on the life cycle of lice. It focuses on removing the live lice and does not require removing nits from the head. Combing treatments are done every 3-4 days over a two week period to break the life cycle of the lice by removing them before they are fully grown and able to spread or lay eggs.
This option is safe for infants and pregnant women. Re-infestation can occur so consult your local health unit if you need more options.
Steps to follow
Do
Remember
Wash hair with ordinary shampoo and rinse.
Note: on average, a wet combing session takes about hour per person.
Apply a generous amount of conditioner (any brand) all over head and scalp. Do not rinse out the conditioner.
Untangle hair with a regular wide toothed comb. Wet conditioner will immobilize the lice.
Comb sections of hair using a metal nit comb. Divide the hair into small sections and firmly draw the comb from the scalp to the end of the hair. After each stroke rinse the comb in a sink or bowl of warm water and wipe dry. Do the entire head making sure the head stays very wet.
Metal nit combs are available at your local pharmacy. If it tugs the hair it may be upside down.
Rinse hair. Leave the hair dripping wet. Repeat step 3 combing without conditioner until no lice are found.
Check the comb and your fingernails for lice (you don't want to give them a ride back to your head).
Repeat steps 1 through 4 every 3 to 4 days for two weeks (for example, wet comb on day 1, day 5, day 9, day 13).
Use a wide tooth comb to untangle and then use the fine tooth metal nit comb again.
If you find any lice following treatment, this is a new infestation of lice and you will need to wet comb the hair for another two weeks.
This breaks the life cycle of the louse by removing the lice before they are fully grown and able to spread or lay eggs.
After treatment checklist
- Wash in hot water, all bedding, towels and clothes used in the past two to three days including those worn during treatment.
- Launder all washable clothing, bedding, and towels in small loads with hot water and/or put in hot dryer for 20 minutes.
- Wash hair brushes, combs and hair accessories (barrettes, ribbons, etc) with hot soapy water.
- Anything that can't be washed (such as blankets, coats, headwear, stuffed toys) can be treated by: placing in a closed plastic bag for 10 days or putting in a hot dryer for 20 minutes or putting in the freezer for 48 hours or ironing it.
- There is no evidence that a major cleaning of the house is needed to get rid of head lice. Only items that have been in direct contact with the affected person(s) need to be washed.
- Repeat treatment according to option chosen.
- Notify those in contact with child that lice/nits were found, such as school, Brownies, Scouts, sports teams, friends.
What treatments should I not use because they are ineffective against head lice?
The following treatments are either ineffective or unsafe (or both):
- Insect sprays (such as Raid)
- Dyes
- Oil (such as WD40)
- Bleaches
- Gasoline
- Chinese chalk
- Flea soap
- Heat directly on scalp
- Alcohol
- Enzyme reactions
- Shaving gel
- Kerosene
- Shaving the head
- Garlic
Note: essential oils (such as pine, tea tree, thyme, rosemary, eucalyptus, etc.) are not recommended at this time due to limited data and possible toxicity concerns.
Resources
- HealthLink BC: Guide to head lice
- Canadian Paediatric Society: Head lice