When a child comes home with a case of head lice, most parents race to the drug store to buy an over-the-counter (OTC) lice-treatment product. These products go by many names, some of them catchy to the point of appearing benign. Many, however, contain some kind of insecticide. That’s right, insecticide. These products are asking parents to shampoo their child’s head with a substance developed to kill insects.
There are a few common insecticides used by one or more retail lice treatments. Most fall into the category of Pyrethroids, derived from Pyrethrum, a powder extracted from a species of chrysanthemum discovered by Chinese herbalists in the 19th century. Pyrethrin is a more refined version of Pyrethrum, and is the active ingredient of several lice treatments. Permethrin, used in other lice products, is a synthetic version of Pyrethrin.
No safe exposure level to Pyrethroids has been established by health regulators, nor has the Occupational Safety and Health Administration (OSHA) set an exposure limit. Though some Pyrethroids have been banned from use in food production, they’re still used in lice treatments.
When it comes to prescription lice medications—which are only to be used after less aggressive treatments have failed—the active ingredients in some prescription products can be even more troubling.
Lindane, a neurotoxin, is commonly used as a pesticide. Known to cause cancer and harm the human nervous, reproductive and hormonal systems,the U.S. has banned Lindane for some uses, and many countries have abandoned it altogether. Surprisingly, however, Lindane is still available in some prescription lice-treatment products.
Malathion, a nerve gas derivative often used for insect control, is also avialable as a prescription lice product and is considered to be safer than Lindane. Malathion is an organophosphate and kills by interfering with the nervous system. It is considered an “unclassifiable carcinogen,” neurotoxin, asthma trigger and suspected endocrine disruptor (meaning it affects normal hormone activity).
It should be said that prescription (and many OTC) lice-treatment products have been deemed safe by the FDA when used exactly as directed. The possible side effects listed on product labels should be noted. That said, one common real world problem is that parents routinely over dose their children and themselves with these products in desperation for a quick resolution of their lice outbreak; or they use the treatments again after the first attempts fails, also in violation of usage directions. Even if applied properly, there are few reasons to think twice before using these treatments as a first line of attack against head lice.
- As noted, these are insecticides. Chemicals manufactured to kill living organisms. You might be willing to put them on your lawn to kill weeds, but on your child’s head?
- They only kill live lice, not the eggs (nits). A single louse can lay over a hundreds eggs, which will hatch into live lice within a week or so. Eggs are the hard part of lice treatment, requiring meticulous, repeated combing, inspection, and combing again.
- Lice are developing immunity to some of the insecticides used in lice treatments. A 2015 study found that lice in at least 25 states have developed resistance to one or more ingredients found in many over-the-counter remedies.
So these are three knocks against chemical lice treatments—they may not be safe, they don’t save time, and they may not even work well.
Lice Clinics of America offers the world’s only FDA-cleared medical device-based lice treatment that kills both live lice and eggs. The AirAllé device uses carefully controlled heated air, and the entire treatment about 90 minutes, without the use of toxic insecticides.
Parents should understand their options when it comes to treating head lice. Often, parents are in a panic and reach for the most accessible option available. But beware—it may not be the best one.