Now that school is back in session, it’s time for this week’s subject. For a great many people, head lice rank high on the “idk” factor.
Some parents, when they discover these creatures in their children’s hair, have done some fairly risky things to get rid of them. Some have used household insecticides such as flea treatments, aerosol sprays. Needless to say, these products are not labeled for that use and would probably have little, if any, effect.
There have even been cases of parents using gasoline and coal tar. Some of the less riskier attempts have included using cooking oil, mayonnaise, Vasoline jelly, Vicks Vaporub and vinegar. Unfortunately, research has shown that these lice can survive quite well covered with these products, even when left on overnight. Regular shampooing won’t work either.
If you find head lice infecting your child, do not panic. Head lice are found in kids from every socioeconomic group. They are not a sign of poor housekeeping. However, they are very contagious (fortunately, they don’t carry any known pathogens). Just remain calm and take immediate action to get them under control.
Don’t start on a frantic cleaning binge. Brushes, combs, hats, helmets and headphones don’t spread lice. It’s the hair to hair contact that does it. The more social your child, the higher the probability they will get head lice. Cleaning your home, washing the bed linen and recently worn clothing won’t help either. Head lice die relatively quickly once off the head. They dehydrate in just a few hours.
Adult head lice are quite small (two to three millimeters). They are tan to white in color. They don’t jump and don’t fly. But, they can crawl very fast, traveling up to 25 centimeters in a minute. This rapid movement and their ability to move quickly away from areas of disturbance makes finding live lice difficult.
If you want to be successful in your search, use hair conditioners and a nit comb. Apply the conditioner to dry hair making certain that you get complete coverage. Use a regular comb to detangle the hair. Immediately, comb through the hair using the nit comb (metal ones are better than the plastic kind). Wipe the conditioner off of the comb with a tissue and look closely for eggs and live lice. Repeat this process at least five times for each area of the head.
Head lice live for a month or so with the adult females laying an average of six eggs per day. The eggs are usually white when laid but turn brown with age. They take around a week to hatch. Eggs are attached to the hair about 1.5 cm above the scalp. If you aren’t certain that what you’re seeing is an egg, try sliding it up the hair using your fingers.
Eggs are quite difficult to move. The glue the female louse uses to attach the egg is strong and similar chemically to the structure of the hair to which its attached, This makes it difficult to detach the egg without damaging the hair. They aren’t hard to see; just use a strong light.
Head lice crawl down the hair shaft to feed by sucking blood. Any treatments should be made to the hair and the scalp. A complete regimen consists of at least two treatments spaced seven days apart. The first treatment gets the adult and immature lice. The second treatment will get the juvenile lice that hatched during the intervening week. You can’t kill an egg until it hatches.
There are a number of treatments available for head lice. The most common of these are organophosphates (Ovide), synthetic pyrethroids (A-200, Clear, Nix, Rid) and chlorinated hydrocarbons (Kwell). If you think there might be some resistance to the product you used, try a new one that has a different class of active ingredient. There is a non-insecticidal treatment called Hair-Clean 1-2-3. This is a mixture of essential and herbal oils (anise, coconut and ylang ylang) suspended in isopropyl alcohol.
Combing is the oldest and safest method to control head lice. Nit combs have been found in Egyptian tombs and dead eggs have been found attached to the hair of 4,000 year old mummies.
Combing is safe. However, when done properly, it takes a lot of time and effort. Even if you use an insecticidal shampoo, you should still use a nit comb to remove eggs. It takes diligence to manage head lice. Don’t rely on itching, scratching or your child’s teacher to alert you. You should check your child periodically. Being a nit-picker can save you a lot of aggravation.
Tim Lockley, a specialist in entomology, is retired from a 30-year career as a research scientist for the U.S. Department of Agriculture. For answers to individual questions, please send a stamped, self-addressed envelope to Tim Lockley, c/o Sun Herald, P.O. Box 4567, Biloxi MS 39535.