Head Lice

What are head lice?

  • Head lice are small insects (no larger than a sesame seed when fully grown) with moving legs. They live very close to the scalp.
  • Nits are not the same as lice. They are the empty dead egg cases which stick to the hair, and look like specks of dandruff.
  • You only have head lice if you find a moving louse (not a nit). Your head does not have to be itchy to have head lice.

How do you get head lice?

  • Because of children’s play activity and close contact, head lice are usually found on children, but can also spread to adults.
  • Head lice infections are caught from close family and friends in the home and community, as well as at school.
  • Head lice live in all types of hair – dirty or clean, short or long.
  • Head lice walk from one head to another, when heads are close together – they do not fly, jump or swim.

How can you prevent head lice?

  • Regular brushing and combing of the hair will help to spot lice early.
  • The best way to stop the spread of head lice is for families to check their heads by regular wet combing using a detector comb.
  • Human head lice are not found on animals or household pets and are not transmitted from pets to humans.

What are the side effects of head lice?

The reaction of individuals to louse bites can vary enormously from person to person. When you have head lice for the first time, you will probably not even realise they are there. However, after a short time (up to a few weeks), you start to itch, and react to the bites. Once you have had this initial reaction, you will experience itching and redness within 24-48 hours, each time you become re-infested. However, some individuals never exhibit symptoms. Itching from large numbers of bites may make the infested individual feel tired, irritable and feverish, hence the term ‘feeling lousy’.

How do you detect head lice?

YOU WILL NEED: A DETECTOR COMB (These can be bought from your pharmacist – ask for help if there are none on display).

1. Wash the hair well and towel dry until damp, but not dripping.

2. Ensure that there is good lighting – daylight is best.

3. You could use a hand lens or magnifying glass (10x). Magnification may help detect nits and lice.

4. Comb the hair with an ordinary comb.

5. 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 ends of the hair. The use of conditioner may ease the process. Pay particular attention to the nape of the neck and behind the ears.

6. Check the teeth of the comb carefully for lice after each stroke. Wipe the comb on a white cloth/towel/kitchen roll to help you to see the lice.

7. Repeat steps (5) and (6) working your way around the head from the top of the scalp to the ends of the hair. If there are head lice, you will find one or more on the teeth of the comb. Once you have finished clean the comb under the tap with water.

8. If one member of the family has lice, check the rest of the family, including adults, as there is a good chance others are infected.

How do you treat head lice?


1. Check and treat all infected members of the family.

2. Ask your GP or Pharmacist which head lice treatment to use. Do not use head lice shampoo. The Pharmacist can advise on any evidence of resistance to treatment and therefore the most appropriate treatment to purchase. Also, the Pharmacist can advise on treatments suitable for people with asthma and other respiratory conditions.

3. Always read and follow the instructions in the treatment pack.

4. Apply the treatment carefully. The usual methods are: Lotions and Liquids In a well ventilated room (open a window), and away from all sources of heat (fi res, cigarettes, hairdryers, lighters or matches). i. Apply the lotion or liquid to dry hair ii. Part the hair near the top of the head, put a few drops of the lotion or liquid on to the scalp and rub in. Part the hair again a bit further down the scalp and rub in some of the lotion or liquid. Do this again and again until the whole scalp is wet.

If you are treating long hair, ensure that you cover the hair down to where the ponytail band would be, UNLESS you are using Dimeticone (Hedrin) which should fully cover the hair. Ensure that you use enough lotion – do not dilute head lice treatments. Take care not to get the lotion or liquid in the eyes or on the face. iii. Let the lotion or liquid dry on the hair naturally. Keep well away from naked flames, cigarettes or other lighted objects.

Do NOT use a hair dryer.

iv. Leave on the hair for the amount of time stated in the instructions. Then wash and rinse in the normal manner.

5. REPEAT THE ENTIRE TREATMENT SEVEN DAYS LATER, using a second bottle of the same lotion or liquid. This should kill any lice which may have hatched since the initial treatment.

6. Check the head two days after the second treatment. If you still find moving lice ask your pharmacist or GP for advice. You should use at least one small bottle of lotion or liquid per head, more if the hair is thick.

How can you carry out contact tracing?

Head lice are likely to have been picked up the lice from a close contact, usually a family member or close friend, who probably doesn’t know they have lice. There should be no reason to feel embarrassed and it is best to inform likely contacts as soon as possible to prevent further spread.

What if the problem won’t go away?

Did You … – use enough lotion/liquid? – apply it correctly? – let it dry naturally? – leave it on for the correct time? – use a second bottle 7 days after the first? – check all your family and friends? – check adults as well as children? – treat all infected contacts at the same time?

Why do we no longer have a nit nurse?

It has been recognised that routine inspections at school by a school nurse are not only ineffective at tackling head lice in the long term, but can lead to a false sense of security. The responsibility for frequent checks must lie with the individual parent/s (who is best placed to detect infestation). In order to encourage this method the Parent Teacher Associations of some schools organise family health promotion sessions with health 755_inside_e.indd 6 2/7/08 9:35:52 am professionals. Many schools will participate in National Bug Busting Days (31 January, 15 June and 31 October) which aim to ensure children and parents know how to detect and treat head lice and stop their circulation.

Where can you go for further help and advice?

Contact the local GP, Pharmacist or Health Protection Nurse

Do those infected with head lice need to stay indoors until the head lice are gone?

There is no need to keep those suffering from head lice indoors, or children from attending school.

Should a child be excluded from school if they have head lice?

No. Exclusion is a disciplinary measure that should be used in exceptional circumstances and as a last resort and should not be used to manage head lice infection.

Do pets get head lice?

Head lice cannot be “caught” from pets and cannot survive on pets. They are human parasites and require human blood for survival.

Do I need to spray my bedding and furniture?

Head lice are human parasites and require human blood to survive. They are not environmental pests so pesticide sprays for furniture and bedding are unnecessary and a serious risk to health. Vacuuming is the safest and best way to remove lice or fallen hairs with attached nits from upholstered furniture, rugs, stuffed animals and cars.

Are lice shampoos potentially hazardous?

There are possible side effects/hazards from using lice shampoos e.g. those with respiratory conditions such as asthma, epilepsy, pregnant women etc. Advice should be sought from your local GP or Pharmacist who will be able to advice further

Should other parents be notified if a child is infected with head lice in their child’s school?

Despite popular belief, letters notifying other parents of cases of head lice do not have any effect in stopping the spread of lice amongst children. However, letters of this kind often have the effect of causing itching and anxiety as a purely psychological response.

Do head lice spread diseases?

No, head lice are not known to transmit any disease agents. However, if the skin is broken by repeated scratching, other infections can be introduced by organisms under the nails, but this is extremely uncommon.

REMEMBER It doesn’t matter how many nits you have, or how itchy your scalp is – if you can’t find a moving louse you don’t have lice.

This information was taken from the Welsh Government’s ‘Facts about Head Lice’ booklet which can be downloaded here.

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