Head lice

The Facts of Lice

  • A head louse is an insect with six legs but without wings.
  • A head louse cannot fly, jump or swim.
  • An adult louse is 3-5 mm in size. Anything smaller is a baby head louse.
  • They live on the hair, close to the scalp and pass from one head to another during close contact.
  • When the baby louse hatches it leaves behind an empty white egg case - this is called a nit.
  • Nits are not real lice. There is no need to worry about them unless you find actual living moving lice.
Adult head lice spread easily among young children affecting boys and girls equally.

All family members and other close contacts can easily carry head lice without knowing.

It can be up to 3 months before symptoms such as itching occur.

How to detect head lice Use a fine tooth detector comb (available from pharmacy). Wash hair well and leave wet but not dripping. Apply a small amount of conditioner. Ensure there is good lighting - daylight is best.

First, comb the hair with an ordinary comb. Then using the detector comb, begin at the top of the head and making sure that the comb is touching the scalp, slowly draw the comb towards the end of the hair.

Wipe the comb with tissue paper after every stroke to check for lice. Repeat, working your way around the head from the top of the scalp to the ends of the hair. This should take 10-15 mins. Rinse the conditioner off after combing is finished.

If you are uncertain about what you find, stick it to a piece of Sellotape and take it to your pharmacist.

The best way to prevent infection is to perform detection combing regularly.

NEVER use insecticides to PREVENT infection or just in case.

How to treat head lice
Only start treatment if a living, moving louse has been found. Insecticide lotions are the usual recommended treatment. DO NOT use head louse shampoo.

  • Apply lotions or liquids to dry hair in a well-ventilated room.
  • Part the hair near the top of the head. Put a few drops of the lotion or liquid on to the scalp and rub it in. Part the hair again a bit further down the scalp and rub in some more of the lotion or liquid. Repeat this until the whole head is wet. You don't need to apply the lotion or liquid beyond where you would put a pony tail band. Take care not to get the lotion or liquid in the eyes or on the face.
  • Let the lotion or liquid dry naturally. Keep well away from naked flames, cigarettes or other sources of heat. Do NOT use a hair dryer. Lotions and liquids must be left on the hair for 12 hours or overnight. Then, wash and rinse hair as normal.
  • You will need at least one small bottle of lotion or liquid per head, more if the hair is thick.
  • Repeat the entire treatment 7 days later, using a second bottle of the same lotion or liquid.
  • Check the head 2-3 days later. If you still find living, moving lice ask you pharmacist or nurse for advice.
Contact Tracing To stop you from being re-infected, it is important to find out where you caught the lice from and also to find out who you may have given them to. You probably caught them from a family member or a close friend, who does not know that they have lice. Inform the school or nursery if your child has head lice, but you do not need to keep them off school. Get in touch with everyone who has been in close (head to head) contact with the infected person. They should all check themselves for head lice using detection combing. Anyone who is infected with living, moving lice should be treated straight away. The Problem won't go away? - Did you....
  • use enough lotion or liquid?
  • apply it correctly?
  • let it dry naturally?
  • leave the lotion or liquid on for 12 hours?
  • use a second bottle 7 days after the first?
  • check all your close family and friends?
  • check adults as well as children?
  • treat all infected contacts at the same time?
Remember: It doesn't matter how many nits you have, or how itchy your scalp is - if you can't find a living, moving louse, you don't have head lice.

Further information

This article published on
28 November 2005

Next review date 11/1/2013


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