Head lice

Head lice are small greyish insects that live on the scalp. They are parasites that feed on a person's blood. There are two things to look for when inspecting someone's scalp for head lice:

• Nits: Head lice lay small beige eggs (called nits) near the roots of the hair. Nits are the size of a grain of sand and hatch after 9-10 days.
• Lice: Adult lice are about the size of a sesame seed and can live up to 30 days on the scalp. Lice can't survive long away from the scalp. They are mostly found near the ears, the nape of the neck, and the forehead. They can also be found in a person's beard or eyebrows.

Head lice are unpleasant, but they aren't dangerous. They don't spread disease and are not a sign of poor hygiene. Head lice are a common problem among children, especially around the beginning of the school year. They can be spread easily in schools and childcare centres. It's not necessary to keep children with head lice home from school or childcare.

The main symptom of head lice is an itchy scalp. The itching is caused by an allergic reaction to the insect's bite. Some people don't have this reaction and therefore have no symptoms.

Causes and triggers

Head lice are usually spread through direct contact with an affected person's head. They can also be spread through contact with an object that's been in contact with an affected person's hair (e.g., hairbrush, comb, hat, scarf, pillowcase). Lice can't jump or fly, but they move very quickly.

Pets can't get or spread head lice.

Treatment

Checking for head lice involves carefully examining the scalp. This should be done in good light, preferably using a fine-toothed comb on wet hair. An affected person can have between 10 and 20 lice on their scalp, so it's important to be thorough. It's recommended to check your child's head for lice in the following cases:

• They complain that their scalp is itchy
• They've been in close contact with someone who has lice
• It's back-to-school season (check once a week at the start of the school year)

If your child has head lice, it's important to take the following steps:

• Apply head lice treatment as soon as possible
  • There are many different treatments for lice. Ask your health care provider for help finding the best product for you.
• Notify your child's school or childcare centre
• Check everyone in your home for lice
• Treatment should be applied only if you find live nits or lice on the scalp
  • It can be difficult to determine whether the nits are dead or alive. If in doubt, consult your health care professional before treating.
• All family members who have head lice should be treated at the same time
• Wash all personal belongings
  • Clean objects that the affected person uses frequently (e.g., pillowcases, bedding, hats, combs, hairbrushes) with hot, soapy water, and allow them to soak for 10 minutes
  • Items that can't be washed should be stored in an airtight bag for 10-14 days
  • You don't need to deep clean your home, as lice can't survive long away from the scalp

To prevent head lice, remind your child to avoid head-to-head contact and not to share items like hats and hairbrushes. It's also a good idea to keep long hair tied back and to check your child's scalp regularly.

When should I see a health care professional?

Speak with your health care provider in the following situations:

• You are pregnant or breastfeeding
• You are allergic to the lice treatment
• You are treating a child under the age of 2
• You need to treat your beard or eyebrows
• You can't get rid of the lice
• The affected scalp has wounds or sores

For more information:

• Caring for kids