Family doctor



HEADLICE - a patient's guide


Headlice have been increasing since the 1970s. They can be hard to eradicate. This article includes some suggestions for treating the problem.



  •   Headlice have been increasing since the 1970s
  • They mainly affect school- age children .
  • Headlice can easily spread to other family members
  • Female lice lay eggs and live about 40 days
  • An itchy scalp can indicate infestation,but some get no symptoms
  • A special shampoo will usually kill the lice , although resistance is a growing problem
  • Prevent lice by not sharing brushes, hats or beds
  • Checking children's hair regularly may help detect lice early
  • Headlice are not a sign of poor hygiene and cleanliness

What are headlice?

 Headlice (pediculus capitus) are a common problem worldwide.

They are small flat insects about 2-3 mm long that live on the scalp and need to feed on their host's blood several times a day to survive.(ectoparasites)

Infestation is a common problem among primary school children,although they can affect any age group . Children are usually infected at school and then the lice spread to family members.

They are spread by direct (usually prolonged) head to head contact such as sitting very close to someone with lice or sharing beds, brushes, combs or hats. They cannot jump from head to head, but swing from hair to hair. They can survive underwater.

Female lice lay up to 10 eggs a night. The eggs can be found glued to the hair shafts close to the scalp. They will hatch in nine days and most live for about 40 days.

What are they symptoms?

People with headlice will have an itchy scalp and often scratch their heads. Scratch marks or a rash can be a sign. However, not all children will complain of itchy heads. Headline can also disturb sleep.

The itching is due to sensitization to the louse saliva, which may take up to three months to develop after initial infestation.

Secondary infection (with bacteria) due to scratching may develop and cause sores that discharge pus.

Finding the headlice is the only way to confirm an infection. The egg cases may persists after the lice have been killed and do not necessarily indicate active lice infestation.

Look for headlice around the hairline or at the back of the neck, behind the ears, and on the crown.

Parents are advised to check their children's hair once a week for signs of lice.


What is the treatment?

As most infestations have been present for some weeks when they are discovered, it is important to trace and check close contacts to see if they need treatment as well.

There are a number of different special shampoo preparations available, none which has been shown to be clearly superior to another. Resistance is a growing problem, and you doctor may be able to advise the best one to try in your area.

Wash the hair thoroughly and use as little water as possible as it dilutes the product. Leave the shampoo on the hair for five to 10 minutes. Use a watch to wait for the recommended length of time.

Repeat the shampoo a week later. The hair does not need to be cut if the treatment is successful.

The lice and eggs can be removed after treatment by combing the hair with a fine-tooth comb.

Other people in the household with visible headlice should be treated.

However, do not use the shampoo if your child does not have lice because the medicine may be less effective in the future.

It may pay to wash bedding clothes and hats to remove any stray hairs that have eggs on them. Wash brushes and hair things as well.

Special combs may be helpful to eliminate headlice, but good comparative studies of this method have not been done.

How can they be prevented?

Children should brush their hair everyday. Brush against the hair backwards because this will help kill any lice.

Do not share brushes or combs.

Children should keep their clothes and hats separate from other children's belongings.

Advise friends and contacts if your child gets headlice.

Future trends

Battery operated combs are becoming available to shock the lice and kill them, however, the use of medicated shampoos is still necessary.

Getting help

Do not delay getting help- there may be an unwarranted social stigma associated with having headlice Anyone can get headlice and it is not a sign of poor hygiene or uncleanliness.

Your doctor, pharmacist, or public health nurse will be able to help.


See also:

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