Prevention and Treatment
What are head lice?
Head lice are small insects that live on the scalp.
Head lice are not dangerous and they do not spread disease, but they are contagious and can be a very pesky problem. Having dirty hair does not cause head lice. Head lice cannot fly or jump and you cannot get them from your pets.
While they may be found anywhere on the head, they prefer to live on the scalp along the neckline and behind the ears. When lice bite the scalp they cause itching.
How can I tell if my child has head lice?
Children may say they have a tickling feeling on their head or may be very itchy on their scalp.
The only way to be sure a person has an active case of lice is to find live lice. Children can have a few nits (lice eggs) without actually having an active case of head lice. Usually children have no more than 10 to 20 live lice.
Lice are not easy to see and can be hard to find. They are about the size of a sesame seed. They are usually greyish white or brown.
Nits are small, oval and blend into the color of the hair. Each nit is firmly attached to a hair. They cannot be washed out or flicked off like dandruff. Finding nits does not mean the individual has a current infestation and they should not be treated based on finding nits.
How do I check for lice?
What is the treatment for head lice?
Overtreatment and misdiagnosis are common.
Check everyone in the home for head lice.
There are a number of very effective treatments for head lice. Most contain an insecticide that kills the lice. They are pyrethrin (found in R&CTM shampoo/ conditioner), permethrin (Nix® or Kwellada-P®) and lindane (PMS-LindaneTM shampoo).
A non-insecticidal treatment called isopropyl myristate/cyclomethicone (ResultzTM) has been approved for use in Canada for individuals 4 years of age and older. It works by breaking down the waxy exoskeleton (‘skin') of lice. The lice get dehydrated and die.
All of the above products require a second application 7 to 10 days after the first treatment.
Tell the pharmacist if anyone needing treatment is pregnant, breastfeeding, under six years of age, has allergies or a serious health problem.
A pharmacist, doctor or public health nurse can help you choose the best product for you.
If live lice (not nits) are found in the hair 24 to 48 hours after a treatment with one product:
Examine all of the household members for head lice everyday for 3 weeks after the first treatment.
Do other treatments work?
Many home recipes and products sold in stores are based on mixtures of essential oils (eucalyptus, lavender, tea tree, etc), salts or other natural substances. Some people have used oils like mayonnaise, olive oil and Vaseline or hair gels to try to smother lice. There is no proof that any of these work.
How can I help the treatment be more effective?
Each product is different and has detailed directions for use. For example one product might say it should be put on dry hair while another should be put on wet hair. Each will say how long it should be left on the hair before rinsing out.
It is very important to read and follow the package directions carefully.
Home treatments, such as vinegar rinses, should not be used as they may make the treatment less effective.
Avoid unnecessary contact with the product since it can be absorbed through the skin.
Children with head lice should be treated and can attend school or child care as usual.
‘No-nit' policies that keep children with head lice away from school are not necessary because:
How can you prevent the spread of head lice?
What cleaning needs to be done?
Lice cannot live for more than 2-3 days away from the scalp so excessive cleaning is not necessary.
Choose the best method to clean the following items (washing in hot water for 15 minutes or running through a drier on the hottest setting):
For items that cannot be washed they should be placed in a sealed plastic bag for two weeks or for 48 hours at -10° C.
There is no need to vacuum or wash floors, carpets or furniture.
Do not use household sprays or lice sprays. They do not work and may be harmful to people.
For more information contact:
See HealthLine Online for more information about head lice.