Head lice: the key is in the comb

The Lice Problem – if you’re a parent you’ve probably had to deal with it at least once. And you dread having to do it again. Every school year, thousands children get head lice. More and more, parents are finding that chemical based lice shampoos just don’t work. Not knowing what else to do, many parents shampoo again with the same, or another, pesticide based lice shampoo, use pesticide based lice sprays on carpets or furniture, wash bedding and clothing over and over, in an attempt to solve the problem. The costs and frustrations mount – and so do the exposures to harmful chemicals. And often, the lice remain.

Head lice can be eliminated – and they can be eliminated without using toxic chemicals, and without spending lots of money. The key is in the comb. A recent study in the British Medical Journal found that finely combing wet hair with a comb specially designed for head lice was four times more effective in getting rid of head lice than malathion or permethrin based lice shampoos. The National Pediculosis (the scientific name for lice) Association agrees. This non-profit group has been working for years to help parents eliminate lice without exposing their children to harmful chemicals.

Their message is comb, comb, comb, but make sure you are using a comb that works. The right comb will be metal, have long teeth finely spaced, and the space between the handle and the teeth will be sealed, so that live lice can’t hide inside. Many combs sold with pesticide based shampoos are not fine enough or strong enough to be effective in removing all lice and nits, the lice eggs which attach to the hair shaft. This is one of the reasons that these products don’t work. Another reason is that many lice have become resistant to the most commonly used pesticides in lice shampoos. The NPA recommends combing hair wet and using the LiceMeister brand comb, which is the only comb which has met their standards for lice control.

Pesticide based lice shampoos are dangerous. They can have harmful immediate and long term effects ( see sidebar). The number of parents who choose not to use pesticide based shampoos is growing. These safety-conscious parents do not want to apply a pesticide to their child’s scalp, and have it absorbed into their blood and circulated throughout their bodies. Perhaps they also realize that lice appear to be developing resistance to the pesticides, just as many bacteria have developed resistance to the overused antibiotics. A side benefit is that these parents are also not sending these pesticides into our wastewater and thus eventually into our groundwater.

There are some non-pesticide based shampoos on the market including several using tea tree oil as the active ingredient. These ingredients are less hazardous than pesticide based shampoos, and lice have not developed resistance to them. However, tea tree oil products can create allergic sensitization, so should be used cautiously. Tea tree oil shampoos should be tested on a small area of skin to make sure the user isn’t allergic before applying to the scalp. Pure tea tree oil is a sensitizer and should not be used.

There are some home remedies which have had reported success, but haven’t been fully proven. These include covering the head with mayonnaise, olive oil or vaseline and leaving it on overnight. In all cases, effective combing needs to be done to remove nits. Some products advertise that they kill all lice and nits without combing, but there is no evidence so far that this is true.

The LiceMeister comb is not widely available in Atlantic Canada, but any pharmacy or individual can order the comb from CanCoast Holdings, 1-877-410-LICE. Stores which do stock the combs have usually brought them in when a relieved and satisfied parent who has used the product brings it to their attention. In southern Ontario, some schools have a comb loan program, where LiceMeister combs are lent to parents whose children have lice, and returned when the problem is solved.

Lice Control DOs and DON’Ts

DON’T: Use pesticide based shampoos.

DO: Shampoo hair with normal shampoo. Use clips to divide wet hair into small sections, and work with one section at a time. Comb from the scalp, depositing lice and eggs in a bowl of soapy water. Some people report using conditioner and leaving it in the hair makes the process easier. Use a fine toothed, good quality metal comb.

DON’T: Use environmental sprays for lice – they are unnecessary and a serious health risk.

Lice infect people, not the home. They are human parasites. Lice cannot live without human blood for more than 24 hours. Nits will not live unless they get a meal of human blood immediately when they hatch.

DO: Vacuum carpets and padded furniture to remove any lice which crawl off the infested person, or hairs with attached nits is enough.

DO: Put bed linens, pillows, stuffed animals and similar items in a dryer for 30 minutes on high heat to kill both live lice and nits.

Lice do not jump or hop. They do crawl and cling. If a louse comes off the head and is left behind on a pillow, head rest, or hat, the louse may infect another person who places their head in that area. Vacuuming will catch these escapees. Experts used to suggest bagging items such as stuffed animals for several weeks to help control infestations, but this is now recognized as unnecessary.

DON’T: Treat family members who don’t have head lice. Treat for head lice ONLY when a person has them.

DO: Check everyone in the family using a good quality lice removal comb.

DON’T: Treat family pets for lice with insecticidal shampoo. Its pointless and potentially harmful (to humans and pets both). Lice cannot live on pets, so there is no reason to fear that lice may be hiding on your dog, cat or guinea pig.

DO: There really is no do for pets and lice. So give your pet an extra hug and be thankful. DO: Consider exploring safe options for flea control for your pets (see www.environmentalhealth.ca/summer01flea.html)

DON’T: Use head lice treatments as a preventative measure. Head lice can’t be safely or effectively prevented by shampooing with either chemical or alternative treatments.

DO: Practice early detection, by making weekly head checks with a good quality comb. Early detection and removing any live lice or nits can keep head lice problems to a minimum. “It only takes a few minutes,” says Bonnie Byers, parent of four. “I check around the ears, the back of the neck, around the bangs and where hair is parted. Lice seem to like these areas best.”

DO: Visit www.headlice.org for a wealth of information on non-toxic lice control, including a video on effective combing methods, and pictures of lice and nits.

What’s wrong with chemical based lice shampoos

The scalp is one of the most absorbent parts of the body. Products applied to the scalp go directly to the blood, without being filtered in any way. Pesticide based lice shampoos contain ingredients which are known or suspected to cause cancer, affect the nervous system, and have other harmful effects. They can trigger asthma or allergic responses. Children, especially children with asthma and allergies, are more vulnerable than adults to these chemicals.

The most common pesticides used in lice treatment in Nova Scotia are permethrin, pyrethrum, and piperyl butoxide. Lindane based shampoos are still approved for use in Canada, and in most provinces are available “behind the counter.” In the US, malathion based shampoos are still common.

Permethrin – A pyrethroid insecticide, permethrin is a synthetic version of an extract from the chrysanthemum. Exposure to pyrethroids has resulted in contact dermatitis and asthma-like reactions. Children with a history of allergies or asthma are particularly sensitive. Permethrin is a suspected human carcinogen and neurotoxin which has been reported to cause temporary nervous disorders in the face and hands. It is also a suspected reproductive toxicant and endocrine toxicant.

Pyrethrum – This is a natural insecticide made from chrysanthemums. Pyrethrum insecticide formulations often contain piperonyl butoxide, a synthetic chemical that increases the potency of pyrethrum. Pyrethrum can trigger allergic responses like skin rashes, hives and asthma. It is a suspected carcinogen, immunotoxicant and reproductive toxicant. Piperonyl butoxide is a suspected carcinogen, neurotoxicant and respiratory toxicant.

Lindane – Lindane was once the lice treatment of choice. It is now recognized as highly toxic, although lindane based lice control products are still approved for use in Canada. Lindane is an organochloride insecticide in the same chemical class as DDT. A nerve poison, lindane is readily absorbed through the skin and is classed as a known cancer-causing chemical in California where it is banned. Documented health effects of exposure to lindane include hormone disruption, dizziness, seizures, nervous system damage, immune system damage and birth defects. Lindane, also an agricultural pesticide, has been found in breast milk and blood samples throughout the world and is banned in at least 14 countries.

Seizures, behavioral changes, attention deficit disorders, brain injury, skin diseases, and even death have been reported to the United States-based National Pediculosis Association’s registry by people who have used chemical treatments to get rid of head lice or scabies.

Toxicity information from www.scorecard.org.