INTRODUCTION
Head lice are tiny insects. They do not have wings, so they cannot fly. Head lice have strong claws and swing from hair to hair – they cannot jump. They live on the hair and suck blood from the scalp. Head lice can only be spread from one person to another by direct head-to-head contact.
Anyone can get head lice – they have no preferences for cleanliness, hair colour, hair type, ethnicity or age. Head lice are a nuisance but they do not cause disease or illness. Itching is often the first thing that raises concern about head lice, however it is not a reliable sign of head lice.
Head lice need to spend their entire life on human heads to survive. Head lice will die from dehydration within 6 – 24 hours when removed from the human head, depending upon humidity and when they last fed. Scientific research has shown:
• Sharing hats presents no risk. It does not increase the chance of getting head lice. Researchers examined hats worn by 1000 school children and found no head lice even when many head lice were found on the children’s heads.
• Placing hair grooming implements in a container of very hot water (60°C) for at least 30 seconds will kill any head lice caught in the comb after grooming. A domestic hot water service usually does not reach 60°C. If you do not have a thermometer, it may be easiest to use water shortly after it has gone off the boil.
• Research and examinations of 118 carpeted classroom floors found no head lice or eggs. When the students from those rooms were examined, they had a total of 14,563 live head lice on their heads.
Incubation Period
The head louse starts as a small egg about the size of a grain of salt which the female louse glues to the base of the hair shaft. Most often these eggs (nits) are found in the hair behind the ears, at the back of the neck, or around the crown and under the fringe.
The eggs hatch in 7–10 days. They mature into an adult louse, which is a wingless insect 2–3 mm long with a flat body and six legs. The adult louse is capable of laying eggs after 6-10 days.
Infectious Period
The infectious period starts as long as the eggs or lice are alive. Live eggs are glued to the hair shaft, usually within 1.5cm from the scalp. Head lice can only survive on human heads and they must feed every 6 hours or they will die from dehydration. Eggs need to be on the head to hatch.
Controlling the spread of infection
Educate staff, children and parents about head lice. Identification of an individual child with head lice is usually an indication of head lice in a much larger group and a group approach rather than an individual approach is needed.
Keep families informed if there is someone within the centre with head lice.
Recommend that staff and children tie back long hair to reduce the chance of transmission.
Detection
Itching is often the first thing that raises concern about head lice; however it is not a reliable sign of head lice. Most children who itch do not have head lice. You can have head lice and not know. Lice move fast in dry hair and are easy to miss. If you find head lice early, they are easier to treat.
Everyone (adults and children) in the family needs to be checked.
Check everyone’s head once a week. If a close contact has head lice, keep checking every 2 days until no lice are found for 10 consecutive days. If you find head lice, you need to decide on a treatment option. Using hair conditioner and combing is the most effective way of finding, and treating, head lice. Conditioner and combing can be used for detection and/or treatment. The conditioner stuns the lice for some minutes so they can be easily removed. Conditioner and combing are reasonably inexpensive.
It also avoids the use of head lice chemicals (pesticides).
Conditioner and combing technique
1. Untangle dry hair with an ordinary comb.
2. Apply hair conditioner to dry hair (use white conditioner as it makes it easier to see the nits). Use enough conditioner to thoroughly cover the whole scalp and all hair from roots to tips.
3. Use the ordinary comb to evenly distribute conditioner and divide the hair into four or more sections using hair clips. A mirror helps if combing yourself.
4. Change to a head lice comb.
5. Start with a section at the back of the head. Place the teeth of the head lice comb against the scalp. Comb the hair from the roots through to the tips.
6. Wipe the comb clean on a tissue after each stroke. In good light, check for head lice. Adult lice are easier to see – young lice are difficult to see. A magnifying glass will help. You may see some eggs.
7. Comb each section several times until you have combed the whole head. If the comb becomes clogged, use an old toothbrush, dental floss or safety pin to remove the head lice or eggs.
8. Repeat the conditioner and combing daily until you find no more head lice for at least 10 consecutive days.
Treatment Options
The two most important things to think about when choosing and using treatments are safety and effectiveness.
Conditioner and Combing Treatment
If you choose the conditioner and combing as a treatment, follow all the steps described in ‘Conditioner and combing technique’. Keep combing the whole head until all the hair conditioner is gone and there is no further lice, nympths or eggs appearing on the paper. Repeat the conditioner and combing daily until you find no more head lice for 10 consecutive days. It is important to continue for 10 days to remove all the adult lice and any young lice that hatch from the eggs before they can reproduce.
Chemical Treatment
When choosing a chemical treatment product, ensure you only choose chemical treatments that are designed specifically to treat head lice.
Choose only chemical treatments which have an ‘Aust. L’ or ‘Aust. R’ number on the label. These products are licensed or registered with the Therapeutic Goods Administration (TGA) in Australia. This means they are approved for safety. Be wary of chemical treatments which are not officially approved. Chemical treatments are divided into 4 groups according to the active ingredient.
These groups are: Pyrethrins, Synthetic Pyrethroids, Organophosphates and Herbal and Essential Oils.
If you use a chemical treatment and it does not kill the head lice, choose a product with a different active ingredient from a different group. Products from the same group will probably not work as the active ingredient is likely to be the same. Your pharmacist can help you choose a product.
There is no chemical treatment which will kill eggs. The eggs will continue to hatch after the treatment. Therefore it is essential to apply the second treatment one week later to kill any young lice that have hatched.
The conditioner and combing treatment can be used in between to help remove the lice that are hatching.
There is no chemical treatment that will work for everyone. Resistance to chemical treatments is a problem in Australia. Research into this problem is continuing. The only way of dealing with resistance is to check for effectiveness every time you use a chemical treatment.
Effectiveness of chemical treatments
It is essential to check for effectiveness after each application of a chemical product (refer to instructions above). Some head lice are resistant to some chemical treatments.
This means that this treatment will not be effective in killing head lice.
To check for effectiveness after treating for head lice, use a fine tooth head lice comb (preferably a metal comb) to comb all of the hairs from roots to tips. After each sweep, wipe the combings onto a tissue.
Repeat until all the hair has been combed at least twice. Wait for 5 minutes. Observe the lice for movement.
Effective: If all the lice are dead the treatment has been effective.
• Apply the same product every 7 days (maximum 3 times) to kill the lice hatching from the eggs. Use conditioner and combing every 2 days in between to improve the effectiveness of the treatment.
• After first application eggs will be present. In 7 days use conditioner and combing to detect lice. If lice are found, apply product again in 7 days.
• After third application, if lice are still present, continue using conditioner and combing only.
Ineffective: If some lice run around or wave their legs and antennae, the treatment has not been effective.
• If a treatment has not been effective, select a product with a different active ingredient. Show the pharmacist your current treatment and request advice on choosing an alternative treatment or consider using the conditioner and combing technique.
For more information please contact your local public health unit, community health centre, pharmacist or doctor.
Resources and Sources
Staying Healthy in Child Care, 4th Ed, NHMRC 2005 Retrieved 16 February 2011 from www.nhmrc.gov.au/publications/synopses/ch43syn.htm
Help! I don’t know what to do about Head Lice, Community Child Care Cooperative Retrieved 16 February 2011 from www.ccccnsw.org.au
NSW Health, Head Lice Information, Retrieved 16 February 2011 from www.health.nsw.gov.au/publichealth/environment/headlice/index.asp
Victoria Health Retrieved 16 February 2011 from www.health.vic.gov.au/headlice/