Nits - Detecting head lice
NHS Choices Medical Reference
It is very difficult to identify head lice simply by inspecting the head. Detection combing is a more reliable method of finding head lice.
Detection combing can be carried out on dry or wet hair. Less preparation is needed to comb dry hair, but wet combing is more accurate because lice remain motionless when they are wet.
Detection combing involves using a special fine-toothed head lice comb that you can buy from your local pharmacy. The comb has a tooth spacing of less than 0.3mm to trap the smallest lice.
Nit combs are not suitable for louse detection. Combs that are used to remove nits must have teeth that are less than the width of a nit apart. This is too close for detecting head lice because lice that are trapped between the teeth can remain unseen and be combed back onto the head unharmed.
Wet detection combing
For wet detection combing, follow the steps below.
- Wash the hair using ordinary shampoo and apply ample conditioner, before using a wide-toothed comb to straighten and untangle the hair.
- Once the comb moves freely through the hair without dragging, switch to the louse detection comb. Make sure that the teeth of the comb slot into the hair at the roots with the bevel-edge of the teeth lightly touching the scalp.
- Draw the comb down to the ends of the hair with every stroke, and check the comb for lice.
- Remove lice by wiping or rinsing the comb.
- Work methodically through the hair, section by section, so that the whole head of hair is combed through.
- Rinse out the conditioner and repeat the combing procedure in the wet hair.
Dry detection combing
For dry detection combing, follow the steps below.
- Straighten and untangle the hair using an ordinary comb.
- Once the comb moves freely through the hair without dragging, switch to the louse detection comb. Comb the hair from the scalp to the end of the hair, combing each section of hair three to four times before moving on to the next section.
- Look out for lice as the comb is drawn through the hair. If you see a louse, trap it against the face of the comb with your thumb. This helps to avoid the louse being repelled by static electricity as the comb is removed from the hair.
- Continue combing the hair, section by section, until the whole head of hair has been combed through.
If you discover head lice in your child's hair, check the rest of your family, and alert close friends and your child's school.
You can attach any head lice that you find to sticky tape and take it to your GP or practice nurse for confirmation and further advice. A diagnosis can only be confirmed if a live louse is found in the hair.
If live head lice are found, take appropriate steps to treat them immediately. See�Head lice - treatment for further details.
Treatment should only be carried out after live head lice have been found. Do not treat hair�'just in case'.