How can head lice be treated?

The best way to comb out lice is as follows:

• First, wet the hair or wash it. To avoid pulling the hair while combing it, you can also use conditioner.
• Start combing right at the roots of the hair and then carefully pull the comb all the way through to the ends at least twice, strand by strand.
• Wipe the comb on a paper towel or cloth after combing through each strand so it's easier to see any lice.

The lice usually can't survive on the comb. But to make sure, you can clean it in 60 degree Celsius (140 degrees Fahrenheit) water after combing.

Combing out allows you to check for lice and can help get rid of some of the lice, but it's not a sure way to remove all of them.

Insecticides have been effectively used to treat head lice for decades. But because they have been used so much, lice have become resistant to them in some European countries. Recent studies have shown that insecticides are now far less effective in France, Great Britain, Denmark and the Czech Republic. There is no research on whether resistance has developed in Germany, too.

The following treatments are considered to be effective and are available on prescription in Germany:

• Allethrin (trade name: Jacutin Pedicul Spray)
• Permethrin (trade name: e.g. InfectoPedicul, Ambush, Nix)
• Pyrethrins (trade name: e.g. Goldgeist, R&C Shampoo)

Each of these products is applied differently, so it's important to read the package insert.

Many parents would prefer to treat the lice without using insecticides. Non-insecticide products mainly contain a silicone oil known as dimethicone. Dimethicone is also found in many cosmetics and used in the production of food.

Products containing dimethicone kill head lice and their eggs by coating them in a thick layer of oil that suffocates them. One advantage of these products is that the lice can't become resistant to them.

Several studies have tested lice treatments containing dimethicone. They show that more than 70 out of 100 children no longer have head lice after the treatment. There is no research comparing the different products to find out which is the most effective one.

Several dimethicone products are available in Germany, most of which can be prescribed by a doctor and are considered to be effective:

• EtoPril
• NYDA
• Dimet 20
• Hedrin Once
• Jacutin Pedicul Fluid

Mosquito Med 10 can also be prescribed. It is made out of thick paraffin instead of silicone oil.

These products differ in terms of the active ingredients in them and the total time they need to stay on. Some of them need to stay on overnight, while others just need to be put on for ten minutes.

Plant-based products contain plant oils. The different products work in different ways. Some aim to suffocate the lice, others act like a kind of neurotoxin (nerve poison). Only one of the plant-based products available in Germany has been tested in studies: a spray made from coconut oil, anise oil and ylang ylang oil (trade name: Paranix), which can also be prescribed. Products made of mineral oil or neem oil are available, too.

Because there's not enough research on these plant-based treatments, it's not possible to say anything about their effectiveness or possible side effects. The same is true for home remedies like vinegar, cooking oil or mayonnaise.

All head lice products can irritate the skin or cause itching for a while. Particularly products containing alcohol can cause a burning feeling. One disadvantage of sprays is that they may cause an allergic reaction if breathed in. Especially if a child has asthma or another respiratory disease, it's a good idea to use a liquid product that can be put on with a comb, for instance.

Regardless of which product you choose, it's important to follow the instructions in the package insert so that the product can work. Some treatments aren’t recommended for very young children or pregnant women. You can ask a doctor if you’re not sure.

Most of the treatments need to be applied again after 7 to 10 days because the lice eggs (nits) can survive the first treatment. The second treatment kills the lice that hatch during the week after the first treatment.

For the treatment to be able to work, it's important to

• apply enough of the product to the scalp and hair,
• spread it evenly,
• leave it on long enough, and
• use it on dry hair (wet hair can dilute the active ingredient).

The treatment is very likely to kill the lice. But it's still important to use a lice or nit comb every three days for about two weeks after the treatment, to check whether all the lice are really gone. Some children may need another treatment, possibly with a different product.

Because some products easily catch fire, the hair must be kept away from candles and other flames while using them. Head lice products should be kept away from your eyes, nose and mouth. If there is contact, it's best to rinse them out with water right away.

According to German law, children who have head lice can only return to kindergarten, day care or school after they've had a treatment that is known to be effective. Effective treatments include the insecticides and silicone-based products mentioned above.

You only need to use the treatment once at first. In other words, you don't need to wait a week until the second treatment is complete. A doctor or pharmacist can also give you advice. Most institutions only ask for a spoken or written statement from parents confirming that their child has been treated. Some ask for a note from the doctor, though.