One of the quickest ways to make your skin crawl is to hear that your child has head lice.  While head lice are an annoyance, these little bugs do not carry any diseases and do not pose a serious health risk.  

What Are Head Lice?

Head lice, or pediculus humanus capitis, are tiny little pale grey bugs that are about the size of a sesame seed.  They live close to the scalp, and feed on small amounts of blood.  

Head lice lay their eggs (nits) close to the scalp.  The nits can easily be mistaken for dandruff.  It takes about 9-10 days for the eggs to hatch.  The baby lice become adult lice within about 14 days – then they start laying eggs again.  The cycle keeps repeating itself until they lice are treated.  

Signs and Symptoms of Head Lice

Head lice are most common in preschool and elementary aged children.  The most common method of spread is from direct head-to-head contact.  Head lice cannot jump or fly.  There is a chance that they can spread by sharing of brushes or hats.  You cannot get head lice from animals. 

The most common symptom is an itchy scalp.  The most common itchy areas are the behind the ears and at the back of the neck.  

Having head lice doesn’t mean your hair is dirty.  Head lice doesn’t discriminate!  Anyone can get head lice.  

How to Check for Head Lice

You need to check for both live lice and also the nits.  If you can find only nits, your child may not have head lice.  Make sure you are in a brightly lit room and have a comb or even a magnifying glass with you.

• Part the hair and look for live lice and nits in one section at a time
• Live lice will avoid the bright lights and they move quickly
• Pay close attention to behind the ears and at the back of the neck
• Nits are small yellow or whitish specks and attach themselves firmly to the hair, whereas dandruff or dirt particles do not

Treatment of Head Lice

Check with your child’s doctor before beginning any treatment of head lice.  The most effective way of getting rid of head lice is with an over-the-counter treatment and the comb-out method combined. 

In Canada, the two most common head lice treatments are: 

• permethrin 1% (NixÒ or Kwellada-PÒ)
• pyrethrin (R&C ShampooÒ)

These products are acceptable treatments in children older than 2 months of age after discussion with your doctor.  Follow the package instructions exactly as written. Do not leave the treatment on longer than intended.  Rinse the hair with cool water over a sink instead of in the bathtub or shower. Sometimes these treatments can make the scalp irritated or itchy.  This doesn’t mean the lice are back.  Some treatments need to be repeated after 7 days.  

Avoid home remedies like mayonnaise, petroleum jelly, olive oil, or tea tree oil – there is no evidence that these work.  Never use gasoline or kerosene – these products are extremely dangerous. 

The Comb-Out Method

This is best done after a treatment with a head lice product as directed on the package.  

• Step 1: Wet your child’s hair. 
• Step 2: Use a fine-tooth comb and comb through your child’s hair in small sections. 
• Step 3: After each comb-through, wipe the comb on a wet paper towel. Examine the scalp, comb, and paper towel carefully. 
• Step 4: Repeat steps 2 and 3 until you’ve combed through all of your child’s hair.

What About The Rest Of The House or School?

Some tips for reducing spread of head lice in your household or at school:

• Wash hats, pillowcases, combs and brushes with hot soapy water and dry for at least 15 minutes, OR
• Store items in an airtight bag for 2 weeks
• Teach your child to avoid head-to-head contact
• Your child should be treated and attend school as normal

This post was co-authored by Erin Manchuk, BScPharm, BCGP and Stephanie Liu, MD, MSc, CCFP, BHSc.