Head Lice - Medicated Treatment

Anti-lice lotions and sprays usually work well to clear head lice.

What are the treatment options for head lice?

Currently, there are five main recommended options for clearing head lice:

  • Dimeticone 4% lotion (trade name: Hedrin®).
  • Isopropyl myristate and cyclomethicone solution (trade name: Full Marks Solution®).
  • Coconut, anise, and ylang ylang spray (trade name: Lyclear SprayAway®).
  • Malathion 0.5% aqueous liquid (has various trade names).
  • Wet combing using the Bug Buster® comb and method.

The treatment chosen may depend on your personal preference, and what you have tried before (if appropriate). Each treatment has a good chance of clearing head lice if applied or done correctly and if all affected people in the household are treated at the same time.

Each treatment is now briefly discussed but for details of how to use each treatment, read the instructions that come with the packaging. (Wet combing treatment is discussed in a separate leaflet called 'Head Lice - Wet Combing Treatment'.)

Dimeticone lotion

Dimeticone is a silicone-based product. It is classed as a physical insecticide and is not classed as a chemical insecticide. Dimeticone has a good safety record and is widely used in cosmetics and toiletries. You should apply the lotion twice - seven days apart. Each application is left on for at least eight hours (overnight) and then washed off with shampoo and water.

Dimeticone is thought to kill lice by a physical process rather than by any chemical effect. It is thought to work by blocking the tubes used by the lice to breathe and by blocking the way the lice pass out water, which kills them. However, it is not thought to kill unhatched eggs. This is why two applications are needed, seven days apart. The second application makes sure that any lice that hatch from eggs which survived the first application will be killed before they are old enough to lay further eggs.

Dimeticone is suitable for all ages, those with skin conditions, and those with asthma. It is available on prescription. You can also buy dimeticone over-the-counter (although not for children younger than six months old).

Isopropyl myristate and cyclomethicone solution

This is classed as a physical insecticide and is not classed as a chemical insecticide. It works in a similar way to dimeticone. You apply the solution to the scalp and leave in place for 10 minutes. The hair is then combed with a fine-toothed comb to remove lice. Then wash using shampoo to remove the solution. Treatment should then be repeated in seven days' time. The second application makes sure that any lice that hatch from eggs which survived the first application will be killed before they are old enough to lay further eggs.

This treatment is suitable for those with asthma. It is not suitable for children younger than two years of age or people with skin conditions. It is available on prescription and also to buy over-the-counter

Coconut, anise, and ylang ylang (CAY) spray

This too is a physical insecticide and works in a similar way to dimeticone. You apply the spray to the hair and scalp and leave in place for 15 minutes. The hair is then combed with a fine-toothed comb to remove lice. Then wash using shampoo to remove the spray. Treatment should then be repeated in seven days time. The second application makes sure that any lice that hatch from eggs which survived the first application will be killed before they are old enough to lay further eggs.

This treatment is not suitable for children younger than two years old, people with skin conditions, or those with asthma. It is available on prescription and also to buy over-the-counter.

Malathion 0.5% aqueous liquid

Malathion is a chemical insecticide that has been used for many years to treat head lice. The malathion kills the lice. There are various brands.

It is suitable for all ages and for those with skin conditions. It is available on prescription. You can also buy malathion over-the-counter (although not for children younger than six months old). You should apply the lotion twice - seven days apart. Each application is left on for at least 12 hours (overnight) and then washed off with shampoo and water. The second application makes sure that any lice that hatch from eggs which survived the first application will be killed before they are old enough to lay further eggs.

(Note: shampoo, mousse and creme rinse preparations of malathion or other insecticides are not recommended as they do not work as well as lotions or liquids.)

What about other treatments?

Various other insecticides have been used in the past. For example, permethrin is no longer recommended because there are concerns that many lice are now resistant to it. Phenothrin and carbaryl are no longer available in the UK.

There are various other treatments that are said by some people to work. For example, tea tree oil, quassia, other essential oils, herbal remedies, electric combs. However, there is a lack of research studies to confirm that they work well in most cases. Therefore, until more research is done, these other methods cannot be recommended.

Do family and friends need treatment?

Only if they have head lice. All people in the same home, and other close head-to-head contacts of the previous 4-6 weeks should be contacted. Tell them to look for lice and treat if necessary. (It used to be advised to treat all close contacts even if they had no symptoms. This has changed to just treating people who have head lice.)

All people with head lice in the same home should be treated at the same time. This stops lice being passed around again.

What about school?

Children with head lice should carry on going to school. Contrary to popular belief, head lice do not spread quickly through schools. Alarming head lice letters from schools are usually unhelpful. You need close head-to-head contact to pass lice on to others. Young children who play closely together may pass lice on. If your child has head lice, a common-sense approach is to tell the parents of their close friends to look out for lice in their children.

Can head lice be prevented?

There is no good way of preventing head lice. Lice repellent sprays do not work very well. If you do detection combing of children's hair every week or so, you will detect head lice soon after they have affected the hair. You can then start treatment quickly and reduce the risk of passing them on to others.

Some other points about head lice

  • Use an anti-lice treatment only when you are sure that you have, or your child has, head lice. Do not use them to prevent head lice.
  • A common reason for head lice to recur in one person is because close contacts (family and close friends) are not checked for head lice, and not treated if they have head lice. The treated person is then likely to get head lice back again from untreated family or friends.
  • After treatment and when the lice have gone, it may take 2-3 weeks for the itch to go fully.
  • Nits may remain after lice have gone. They are empty eggshells and stick strongly to hair. They will eventually fall out. If you prefer, a fine-toothed 'nit comb' can remove them.