Having head lice, also called nits, doesn’t mean you’re dirty. Children are most commonly affected, but anyone with hair can catch them.
Head lice are tiny insects that live in human hair. They’re very small (about the size of a sesame seed) and are browny-grey in colour. They have six legs, each with a claw on the end. They use these to cling on to hair, and they survive by biting the scalp and feeding on blood. This often causes itching, but not always.
The female head lice lay eggs in sacs which stick to individual hairs. A baby head louse then hatches seven to ten days later.
If your child has head lice, you might be able to spot the remains of the tiny white egg in their hair. This is called a ‘nit’. Some people also use the word ‘nit’ to mean ‘head louse’.
Ten to fourteen days later, the baby head louse is ready to have babies of its own.
Head lice crawl from head to head when you’re close to someone who has them. Children are particularly at risk, because they’re often in close contact with other children at school.
However, head lice can’t fly or jump, and it’s very rare to get head lice from a pillow or a towel as they can’t survive away from a human head for very long.
How to spot them!
Head lice can be difficult to detect, even when you closely inspect your child's head.
If you think your child may have head lice:
- Check your child's hair. The most common places for head lice to lurk are in the hair behind the ears and at the nape of the neck. If you still can’t spot any lice, comb the child's hair with a special ‘nit comb’. These are available from most chemists. It’s easier to spot head lice as they fall out if you comb the hair over a piece of white paper.
The wet combing method involves removing the head lice by systematically combing the hair using a special fine-toothed comb.
The comb's teeth should be spaced less than 0.3mm, but at least 0.2mm, apart. Lice can be trapped between the teeth of nit combs with a tooth spacing of less than 0.19mm and remain unseen.
Combs are available from pharmacies.
The use of medicated products is not necessary for wet combing. This is advantageous because head lice are becoming more resistant to the insecticides commonly used to remove them.
However, for wet combing to be effective, it involves regular and thorough combing which is time consuming. The wet combing method is described below.
- Wash the hair using ordinary shampoo and apply plenty of 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 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 conditioner and repeat the combing procedure in the wet hair. Repeat the procedure on days five, nine and 13 so that you clear young lice as they hatch, before they have time to reach maturity.
The length of time it will take to comb your child’s hair will depend on the type of hair your child has and how long it is. For example, short, straight hair can be quickly prepared and can be fine-toothed combed in a few minutes, whereas longer, curlier hair will take longer to comb.
Medicated lotion or spray
Using medicated lotion or spray is an alternative method of treating head lice. However, no medicated treatment is 100% effective. Your pharmacist will be able to recommend an over-the-counter lotion or spray.
Medicated treatments should only be used if a living (moving) head louse is found. Crème rinses and shampoos are not thought effective and are therefore not recommended.
Ensure you have enough lotion to treat everyone in your family who is affected. Use enough to coat the scalp and the length of the hair during each application.
Follow instructions that come with the medicated lotion or spray when applying it. Depending on the product you are using, the length of time it will need to be left on the head may vary from 10 minutes to 8 hours. The normal advice is to treat the hair and repeat the treatment after seven days. Some medicated products also supply a comb for removing dead lice and eggs.
Traditional insecticides must not be used more than once a week for three weeks in a row. Some products also carry a fire warning.
Some medicated products may be capable of killing eggs as well as lice, although there is no certainty of this. Check for baby lice hatching from eggs 3-5 five days after you use a product, and again 10-12 days afterwards.
A minimum of two applications of lotion are needed to kill lice over the hatching period because the lotions do not always kill louse eggs.
If the lice appear unaffected by the product (some lice may develop resistance to particular insecticides), or if the problem persists, seek advice from your school nurse, health visitor, pharmacist or GP.
Always seek the advice of a healthcare professional before using medicated head lice lotions on the following groups: young babies (under six months old), pregnant women, people with asthma or allergies It is recommended that pregnant women use either wet combing or 4% dimeticone lotion, which is licensed for use during pregnancy and breastfeeding. You should always carefully read instructions before using medicated head lice lotions.
Head lice and clothing
Healthy head lice do not deliberately transfer onto clothing, bedding or soft toys. Their life span is about three weeks and when they fall from the head they are dying and unable to breed. Hot washing or fumigation is not necessary to control head lice.
Lice that fall from the head during chemical treatment should be promptly disposed of. They may recover if they are resistant to the insecticide or have not been fully coated in the product.
Head lice on combs
Healthy lice that get caught on brushes or combs can re-establish if they get back onto a person's head. Inspect brushes and combs that are used during treatment and remove any lice before the next stroke.
While wet, head lice appear lifeless, but they mobilise as they become dry. However, these lice will die after a day or two if they are prevented from feeding on human blood. You should also be aware that head lice can be flicked from dry hair during vigorous combing. If they land on someone, they will try to climb up to the head.