So your child has been sent home from school with head lice. Welcome to the annual back-to-school nightmare of millions of American parents. Believe it or not, head lice infestation is more common than all other communicable diseases and conditions added together.
What do you do? If you’re like most parents, you’ll probably head for the pharmacy. There you’ll be directed to shelves of over-the-counter treatments, most likely Nix, Rid, A-200, Pronto Plus, or generic versions of these.
Or you’ll call your doctor, who might tell you to use these over-the-counter medications but leave them on all night rather than the hour recommended by the instructions. Or she might suggest a prescription-only medication, most likely Ovide or Kwell.
But wait—before you douse your child’s head with this stuff, you might want to know what’s in it. The answer: neurotoxins, which kill lice by attacking the central nervous system. Rid, Pronto, and A-200 contain pyrethrins, and Nix contains permethrin, all used in common garden pesticides. Ovide contains an even stronger neurotoxin, malathion. (Yes, that’s the same pesticide many communities banned a decade ago.)
Needless to say, these pesticides aren’t something you’d normally want to expose your kids to. Pyrethrin exposure has been linked to asthma and other breathing problems in children, as well as skin rashes. They’re also probable endocrine disruptors and may raise breast cancer risk by elevating estrogen levels. Lindane, the oldest neurotoxin used for lice treatment and the active ingredient in Kwell, has been banned in 52 countries and restricted in 33 others for causing serious side effects, including seizures, stiff neck, lethargy, and slurred speech.
What you really might want to know, though, is that not only are these lice treatments potentially toxic—they don’t even work.
The manufacturers won’t tell you that, and your child’s doctor probably won’t either. But research published this spring in the Journal of Medical Entomology revealed that 99.6 percent of the lice found in the United States are "super lice" resistant to pyrethrins and permethrin. It makes sense: Just as bacteria mutate to make an end run around an antibiotic, so too do fast-reproducing head lice, which mutate to survive the neurotoxic onslaught.
So what do you do?
Let’s start with a few facts you need to know to understand just what you’re up against.
- Lice are minuscule. A full-grown louse is the size of a pinhead. During the nymph stage, which lasts seven to 10 days, they’re practically invisible.
- Lice are fast. Entomologists say they can crawl through hair at 12 miles a minute.
- Lice are fertile. A female head louse lays about 10 eggs—known as nits—a day and up to 200 during her life cycle. That’s 10 eggs a day from just one bug.
- Nits stick hard. Lice treatment products often promise to dissolve the “glue” that attaches each nit to the hair shaft. But honestly, it’s not glue—it’s more like cement. Try combing out every single nit, as you’re instructed to do, and you’ll see what I mean.
So how do you get rid of head lice—hopefully without poisoning your child or the environment? There’s a new pesticide product on the market: prescription-only Natroba, which contains spinosad. A “natural” chemical derived from a type of soil bacteria, spinosad is the ingredient used in many systemic flea treatments for dogs and cats. One big advantage of this treatment is that it’s a 10-minute application that supposedly doesn’t require nit combing.
There are also several disadvantages. One, it’s a pesticide. While the side effects found in clinical trials were mild (primarily eye irritation), spinosad is still a pesticide, and we all know how pesticide risks tend to turn up years after products are on the market.
Another disadvantage: In clinical trials, it was effective in just 86 percent of cases, and you don’t want to be in that 14 percent. It’s expensive: $220 if you can’t get your health insurance to cover it, which many don’t.
There’s another new prescription-only treatment that’s not a pesticide. The active ingredient in Ulesfia is a strong concentration of benzyl alcohol, which stops lice from breathing, so it’s a lot safer—the primary downside being risk of skin irritation, as with any alcohol product.
But Ulesfia has no effect on nits, so you still have to get those out with a nit comb, which any parent who has dealt with lice will tell you is difficult to do thoroughly. Treatment requires two applications, two weeks apart; the second application kills the lice that have hatched since the first application.
What else works? There are electronic combs, which zap lice as they scoop them up, and devices that kill them by blasting them with hot air. (Don’t try this with a home hair dryer; you can burn your scalp.) They don’t have much scientific evidence to back up their claims, but they are nontoxic, and many parents swear by them.
Some experts recommend suffocating lice with Vaseline, mayonnaise, Cetaphil lotion, or another gooey substance. The rub: Lice can hold their breath for up to 8 hours, so you have to leave the stuff on overnight, with your head wrapped in uncomfortable plastic. Nits don’t die from suffocation, so to make this work you have to repeat it to kill each new generation of nymphs as they hatch.
The products you’re least likely to hear about—and that I had the best luck with—are several all-natural solutions that dissolve the exoskeletons of lice and the shells of nits using enzymes, alcohol, and even salt. A second solution helps to weaken the cement holding the remaining nits to the hair so they come out when you comb.
Made and sold by mom-and-pop companies with little marketing clout, these products (ClearLice, Lice B Gone, Lice R Gone, HairClean 1-2-3) are more likely to be found in health food stores, by digging online, or by word of mouth from fellow parents weary of failure after trying traditional treatments.
Whatever treatment you choose, check your child’s head and comb out nits every day for at least two weeks. Some studies show good old nit-picking to be the most effective treatment of all.