Head Lice - your questions answered

What are head lice?

Head lice are tiny parasitic insects that can be found in some people's hair; they are also known as pediculus humanus capitis. It is very common to have head lice and most people will have it at some point in their lives. Head lice are most often found in children but can also be found in adult hair.

Who is at risk of head lice?

Any person who has close contact with somebody with head lice is at risk of having head lice. They are usually spread through head to head touching or contact with contaminated items such as hair brushes, hats and scarves. It is common for young children to have head lice and family members often find that they also get head lice. Girls and women are more likely to have head lice than boys and men. In most cases, personal hygiene has naught to do with having head lice.

What do they look like?

There are three different types of head lice:

  • Eggs (also known as nits): nits are the eggs of head lice; they are small and difficult to see, especially in blonde or white hair, as they are usually white or yellow in colour. Eggs are often mistaken for dandruff and they are laid by adult head lice, usually at the foot of the scalp. Eggs are connected to the hair shaft and usually hatch after around seven days.
  • Nymph: nits hatch and become nymphs, which are baby lice. Nymphs look the same as lice but they are smaller. Nymphs feed on blood to survive and develop into adult lice after seven days.
  • Lice: adult lice are a similar size to sesame seeds, have six legs and are usually tan or grey in colour. Female lice are typically larger than male lice and lay eggs, which hatch after around seven days. Lice can survive for up to thirty days but they need blood during this time. If they fall out of the hair they usually die within forty-eight hours.

Where are head lice found?

Head lice are normally found around the hair line at the rear of the neck and around the ears. Head lice hold onto the hair with their claws, which are found on their six legs. It is rare for head lice to be found on the eyelashes and eyebrows.

What are the symptoms and signs?

Common symptoms include:

  • Itching (brought on by an allergic response to the insect bites)
  • Feeling irritable
  • Feeling creatures in the hair and experiencing a ticklish sensation
  • Getting sores caused by itching and scratching which can become contaminated.

How did my child get head lice?

The main way of getting head lice is to come into contact with somebody else who already has the condition. Head lice can also be spread via contact with contaminated items such as hats and hair brushes, though this is less common. Head lice are spread very easily among children as a result of playing together and spending lots of time in close contact with other children.

How are head lice infestations diagnosed?

Head lice infestation is identified by examining the head and going through the hair using a fine comb. It can be difficult to see adult lice because they are small and move quickly, but the detection of eggs close to the scalp indicates infestation. Head lice infestations can usually be diagnosed by parents, but if you have any doubts or you want advice about treatment you can see your school nurse, pharmacist or family doctor.

How can a head lice infestation be treated?

The aim of head lice infestation treatment is to kill the lice. It is important that all members of the family with symptoms of an infestation are treated. It is also important to wash bedding, clothing and towels.

Treatment involves using prescription or over-the-counter medicine to kill the lice. You should follow these simple steps:

  • Remove clothes from the waist up to prevent clothes from getting wet.
  • Apply the medicine to the hair according to the instructions that come with the medication. If the child has very long hair an additional bottle of medication may be required. Leave the medication on the hair for as long as suggested in the instructions. Avoid using shampoo before using medication and do not wash the hair for at least 24 hours after the medication has been applied.
  • Wear clean clothing.
  • Comb the hair around 12 hours after treatment, and if there are a few live lice remaining but you notice that they are lethargic, comb them out along with the dead lice. If the lice are still active and there are no dead lice, it is likely that the medicine is not working and it is advisable to try a different medication.
  • Check the hair for dead lice every day for 2-3 weeks after treatment using a nit comb, and then continue to do this until there are no head lice or eggs.
  • Follow the medication instructions as some medicines should be re-used 7 days after to prevent recurrent infestations.

Treating the household

Head lice that fall out of the hair do not survive for long, but it is possible for them to be spread via contact with clothing and items worn or used by an infested person. It is worth spending a short time treating the household to prevent re-infestation, which involves:

  • Washing clothing, towels and bedding on a hot wash cycle to kill the lice and dry cleaning items that cannot be machine washed.
  • Soak nit combs and hair brushes in alcohol or hot soapy water for one hour.
  • Hoover the house, including the floors and sofas; although the risk of infestation from lice that have fallen onto the floor or sofa is small, there is still a possibility.

Preventing re-infestation

Head lice are commonly spread via head to head touching, so if a child has head lice it is advisable to treat them as quickly as possible. During treatment try to prevent children touching heads and avoid sharing of clothes, combs, hats or bedding.

My child has lice but I don't, should I treat myself?

You should not treat your head if you do not have head lice, but do check your hair every 2 to 3 days for signs of an infestation.

Is head lice medication sometimes ineffective?

In some cases, head lice can become resistant to medication in the way that bacteria can become resistant to antibiotics. If this is the case try using a different type of medication. Head lice medication can be ineffective for the following reasons:

  • Misdiagnosis: treatment is only recommended when lice or eggs are found within a quarter of an inch of the scalp. If they are only found far away from the scalp this indicates an old infestation and treatment is not required.
  • Not following instructions: it is important to follow the instructions that accompany the medication. Common problems include making hair too wet, not leaving the medication on for long enough, shampooing the hair before or shortly after using the medication, or not using enough medication and not combing the hair. Combing is important because it removes dead and active lice from the hair.
  • Resistance to the medication: if the medicine does not destroy any of the head lice within 48 hours of application, it is likely that the lice are resistant to that particular type of medication.
  • Treating eggs: medication is usually effective at killing live lice but it is very tricky to kill the eggs, and this is why it is important to re-treat the hair after a certain period of time and follow the instructions carefully.
  • New infection: it is possible to have recurrent head lice infestations. This is most common in children as infestations tend to be passed around classes and families. Treating all infested people at once will help to prevent re-infestation.

Should I treat my pets?

No, there is no need to treat pets as lice cannot live on pets.

Can I treat my child under 2 years old using over-the-counter medication?

Before you try medication comb the child's hair with a nit comb and remove any eggs or live lice. If there are still lice present ask your family doctor or nurse for advice about using medication.

Which over-the-counter medications treat head lice?

There are many different brands of head lice medication but all medicines contain one of these ingredients:

  • Pyrethrins (often combined with piperonyl butoxide): these are natural derivatives of the chrysanthemum flower and are used to eradicate active head lice, but they cannot be used to destroy un-hatched eggs. It is advisable to repeat the treatment after 7 days to exterminate newly hatched lice. Brand names include A-200 and Pronto.
  • Permethrin: these are similar to pyrethrins but are more effective in killing newly hatched lice. The treatment continues to work several days after the initial application, although repeat treatment is advised. Brand names include Nix.

Which prescription drugs treat head lice?

  • Malathion: when used properly this medication is very effective in treating head lice. Medication lingers on the hair and is able to eradicate recently hatched lice for up to seven days after first application. Malathion is suitable for children over the age of 6 and adults. Side-effects are rare but sores may sting if they come into contact with the medication.
  • Lindane: this medication is safe when used as instructed, but if the medication is not used as directed it can be toxic. For this reason, the drug is usually only used when other medications have been ineffective.

Which head lice medication is best?

If you need advice about choosing a medication, ask your pharmacist for advice or talk to your doctor or nurse about treatment options.

Notes for treating head lice

It is important to follow the instructions and use the recommended amount of medication. It is also important to avoid using the same type of medication more than three times if results are ineffective. If this is the case try another medication. It is also advisable to avoid mixing medications.

Are household sprays recommended to kill head lice?

It is not advisable to spray the house to try and treat head lice.

Should I arrange for a pest control firm to spray the house?

No, this is not required. Vacuuming the house, treating the affected individual and washin

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