Head lice (Pediculus humanus capitis)  are small, wingless parasites that live on & spend their entire life cycle on the human scalp, feeding off blood. They are most commonly found in school aged children although can infest anybody. Girls appear to get head lice more often than boys.

While often frustrating, head lice are not dangerous. Unlike some other parasites, head lice aren't known to be vectors of disease & they are not a sign of poor hygiene. Head lice can not live on pets, you can not pass head lice to your pets, nor can you catch head lice from your pet. It is human to human contact only.

Infestation with lice is known as pediculosis.

What's the difference between head lice & nits?

Head lice are the adult insects, nits are their eggs.

How long do lice live off the head?

Lice can survive between 1 - 2 days off the head.

How are head lice spread?

Head lice are wingless & have extremely short legs, making them unable to fly, jump or swim, but they can crawl very quickly from head to head. Head lice are spread with head to head contact, for example when hugging or playing closely.

Transmission may also occur via indirect contact such as sharing a hairbrush or hat.

What are the signs of head lice?

Many people with head lice have no symptoms at all. But common symptoms include;

• Itchy head. Although it should be noted that not everyone with head lice will itch. Therefore it is important you regularly check your child's hair for signs of head lice or nits.

• You may see either head lice or nits in the hair.

Many cases of head lice are discovered when lice or lice eggs (nits) are observed.

How do I check for head lice?

As has already been stated, head lice can move very fast. To check for head lice, do the following;

• Get under good light.

• Part hair in sections & apply conditioner to dry hair. This stuns the hair lice &  makes it difficult for them to run around.

• Comb each section with a head lice comb in each section, pay special attention close to the scalp, around the nape of the neck & behind the ears.

• Wipe the conditioner onto a tissue & inspect for signs of head lice & or eggs.

• Once you have combed the hair, clean the comb & immerse in hot water for 20 minutes.

Head lice treatment:

Which every method you choose, you must follow the instructions carefully. If you do not follow procedures carefully you will likely not kill or remove all nits & head lice & the cycle will continue.

Conditioner & lice comb - Apply any type of white conditioner to dry hair (a cheap brand will do). Section the hair & run the comb through from scalp to the end of the hair. Have a bowl of boiling water close by to rinse the comb out after each stroke. Look for brands containing "dimethicone" (for more information, see below).

Repeat this process every day for 14 days.

NB: Having tried a plastic lice comb & found it ineffective, I would recommend a metal comb.

Dimethicone is a silicone based product found in some head lice products & some hair conditioners (Pantene is one such brand). It has been found to be an effective method of killing head lice. It is a physical control method, not a chemical one, ie; it suffocates and/or dehydrates them. Apply to the hair, cover with a shower cap and leave overnight. Wash off the next morning. The egg cycle is every 7 days, so re-apply twice a week to ensure you kill any newly hatched head lice. Because this is a physical control method, resistance build up isn't likely to become a problem.

Insecticides - These are available over the counter from your chemist. They generally come in mousse or shampoo & are applied to dry hair & left on for a specified amount of time (this varies from brand to brand). They are then shampooed off. The insecticides don't always kill off every head louse & some nits may remain, only to hatch a few days later, so the product is generally re-applied 7 & 14 days after the first treatment. Resistance may be a problem with insecticides, so you may need to try a different products. It is extremely important you follow the manufacturers instructions when using insecticides.

These products shouldn't be used in children under 6 months, if you are pregnant, breastfeeding or suffer allergies. Check with your doctor if you are unsure.

Many people recommend using the shampoo/conditioner method between treatments.

Do not:

Use flea products designed for pets on to treat head lice.

Use kerosene.

Preventing head lice & avoiding re-infestation:

• When using an insecticide, always follow the manufacturers instructions.

• Frequently check for signs of re-infestation & if it does happen, switch to a different insecticide.

• Wash pillowcases, scarves & hats worn by anybody who has head lice. Tumble dry for 20 minutes.

• If you have items such as soft toys or cushions that can not be washed, place in a plastic bag, secure tightly & leave out in the sun for a few days.

• Check other household members thoroughly, treat if necessary.

• It is important to notify anybody you or your children have been in contact with if you have an outbreak of head lice. That includes friends & family, schools, daycare etc.

• Over time, head lice can develop resistance to products, therefore if you use a treatment & it has not worked, use a different treatment.

• Don't share combs, brushes, hats etc., with anybody.

• It doesn't hurt to use the conditioner/comb method on your children once a week just as a precaution.

• If you are using an insecticide, between treatments wash the hair in tea tree shampoo.

• Many people recommend spraying the hair with a solution of water & a few drops of tea tree oil. This can also be sprayed onto hats.

• After spraying the hair with the tea tree solution, tie long hair into plaits (braids), use hair pins to hold back any loose hairs and then apply hairspray.

Can you get lice from pets?

No, head lice are host specific. It is not possible to catch lice from a pet. Nor can you pass head lice onto your pet.

Also see:

How To Get Rid Of Nits

Please note:

The medical articles on this site have not been written by a medical professional & should not be considered a replacement for professional advise. The articles are provided for informative purposes only.

While great care has been made in the creation of these articles, we cannot guarantee the accuracy or omissions on these pages. If in any doubt whatsoever, seek professional medical advice.