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If you have young children in school, you’ve probably worried about them picking up lice. An estimated 6 to 12 million people deal with this itchy problem every year, according to the Centers for Disease Control and Prevention (CDC).
A new Consumer Reports nationally representative survey of 2,016 U.S. adults found that among those with children under the age of 18, 21 percent said that someone in their home has had lice within the past five years.
Head lice are sesame-seed-sized, wingless insects that feed on human blood. “As far as we know, [they] do not transmit any human disease,” says L. Paul Guillebeau, Ph.D., professor of entomology at the University of Georgia.
That means their presence on your child’s head doesn’t constitute a medical emergency. Still, lice are distressing, and their bites cause intense itching, which can lead to sores and possible secondary infections.
You may have heard the term “super lice” lately—super lice are just like regular lice except that they’ve acquired genetic mutations that make them resistant to plant-derived insecticides called pyrethrins and their synthetic cousins, pyrethroids. These are the active ingredients in many over-the-counter lice treatment shampoos. Research suggests that super lice are becoming almost ubiquitous, says Michael Hansen, Ph.D., CR's senior scientist.
That can make treating a head lice infestation tricky. Here, we explain how to protect your family from lice, plus what treatments you should turn to in case a family member picks up lice.
Protect Your Family
Lice can crawl from one head to another in seconds—for instance, when children touch their heads together during play or when they share a comb or a hat.
If a friend, a relative, or your child’s school reports a head lice infestation, inspect your child right away. A single female louse can lay up to six tiny, pearl-colored eggs, or nits, a day. They lay the eggs near the base of a hair shaft, especially behind the ears or on the back of the neck. A child's first-ever infection might not be detected for a month, because that’s how long it takes to develop a sensitivity to the lice saliva, which is what causes the itching. During that first month, you might mistake a lice infection for dandruff or eczema—but a lice infestation doesn't go away after shampooing.
If your child has head lice, all household members should be checked and treated, if necessary. You don’t need to go crazy with the housecleaning because head lice won’t survive long if they fall off a person and can’t feed. To prevent reinfestation, concentrate on cleaning the things that your child’s head came into direct contact with in the past few days.
Wash or dry clothing and bed linens at temperatures above 130° F. This will kill stray lice and nits. Seal clothing or other items that are not washable in a plastic bag for two weeks, or put them in the dryer. Soak combs and brushes in very hot water for 5 to 10 minutes.
Remind your children not to share combs, hair ornaments, or hats, and ask them to stuff their jackets into their backpacks at school, rather than hang them on a communal hook.
The Lowdown on Lice Treatment Products
To provide advice on lice treatments, members of CR’s product safety team and our senior scientist, Michael Hansen, Ph.D., reviewed existing evidence about lice treatment options. As we’ve done for several years, we recommend combing out lice from wet hair, without the use of any pesticide products, as a top choice for parents. Here, we offer more advice on how to perform combing, plus important information about a number of other available treatments.
If you do opt for a lice-fighting product, be sure to follow the directions carefully, and pay attention to whether or not a follow-up treatment is recommended. Because many products don’t kill nits (lice eggs), an additional treatment a few days later may be necessary to get rid of any newly hatched lice. Some products may also recommend combining treatment with combing.
And remember that even the most effective methods of tackling a lice infestation aren’t guaranteed—you may need to try more than one strategy.
Although products abound for getting rid of lice, to eliminate the pests, no special substances or pesticides are needed. Wet combing involves carefully combing with a nit comb to physically pick out nits and lice.
What to know: Our experts say that wet combing is a great approach to treating head lice. It can be time consuming and requires perseverance, but no pesticides or pricey products are involved. Here’s how to do it:
Coat your child’s hair and scalp with conditioner or a safe lubricant such as olive oil. Use a wide-tooth comb to separate hair into sections. Follow with a metal nit or flea comb, available at drug or pet stores, concentrating on the area close to the scalp. After each comb-through, wipe the comb on a paper towel and inspect for lice. Continue combing until no lice are found; a single session can take 15 to 60 minutes, depending on the length and thickness of hair.
Repeat every three to four days for several weeks, and continue regular combings for two weeks after any session where an adult louse is found.
You can also hire people to do the combing for you—a quarter of our survey respondents told us they’d hired a professional nit picker or “lice lady” to do the combing for them when their child had lice.
When we asked U.S. adults what products they used on their children to treat a lice infestation if they experienced one, the greatest proportion—35 percent—told us they used “natural shampoo,” such as the products Lice Shield or Hair Genies. These products claim they can prevent or reduce the risk of getting head lice.
What to know: These products aren’t labeled as treatments for an active lice infestation, though that’s how our survey respondents told us they’ve used them. We couldn’t find any evidence that suggests these products can treat an existing infestation.
And even as preventatives, these products may not be a great bet. In 2014, the Federal Trade Commission charged the manufacturer of one such product, Lice Shield, with false advertising for claiming that its product reduced the likelihood of a lice infestation. (The company, Lornamead, settled the complaint by paying $500,000 and was “prohibited from making further deceptive lice-prevention claims,” according to the FTC. We reached out to Lice Shield to find out what evidence they now have to back up their claims. We haven't yet heard back from them, but we'll update this story when we do.)
Using one of these preventative shampoos is likely to be a waste of money, says Jody Gangloff-Kaufmann, Ph.D., coordinator of community integrated pest management (IPM) at the New York State IPM Program. She doesn’t know of any substances that have been shown to repel lice effectively. “Lice are more compelled to eat than they are repelled by any smell,” she says.
As noted, over-the-counter products that contain pyrethrins or pyrethroids (like permethrin) are unlikely to offer much relief because many to most lice are now resistant to those chemicals. In one 2016 study published in the Journal of Medical Entomology, researchers collected lice from 138 different sites in 48 states. They found that 98 percent of those lice had genetic mutations that would make them resistant to permethrin and pyrethrin, the active ingredients in Nix and Rid.
What to know: The scientific evidence on pesticide resistance suggests that these products are unlikely to be effective. Our experts recommend skipping them. “These products can cause side effects, like burning or skin irritation,” notes CR’s Michael Hansen, Ph.D. “Given that they’re highly unlikely to do any good, they’re just not worth the risk.”
In fact, they could prolong a person’s suffering, because it takes a few days to know whether the product is working. If you do try one of these products and it fails, switch to another method. It can be dangerous to do the same pesticide treatments over and over, says Gangloff-Kaufmann.
Household Pesticide Products
You may think that pesticide fogs or “bug bombs” could be used to control a lice infestation in the home. But these chemicals can be toxic if inhaled, and they pose an explosion risk near a heat source.
What to know: The CDC recommends against these, and so do CR’s experts. They are unnecessary. As noted, lice can’t live for very long away from actual human heads, where they draw their blood meals. So most lice around the house will die anyway.
A variety of prescription treatments are available for head lice. The Food and Drug Administration has approved several of these in the past decade. One, topical spinosad (Natroba and generic), contains a chemical derived from bacteria that acts on the lice’s nervous systems (they become overexcited, then paralyzed, then die). Another, topical ivermectin (Sklice), works similarly (ivermectin is a common veterinary medicine, too).
A third non-pesticidal treatment that works by suffocating lice, benzyl alcohol lotion (Ulesfia), was recently discontinued by its manufacturer for business reasons. A post on the FDA’s website notes the discontinuation was not due to any problems with safety or efficacy. We reached out to the company for more information but have yet to hear back.
Two older prescription medications, malathion (Ovide and generic) and lindane (Scabene, Kwell, and generic) are also available.
What to know: According to clinical trials of the drugs, spinosad and ivermectin appear to work relatively well against lice. They act via different mechanisms than the pyrethrins or pyrethroids. But you'll need to go to the doctor, and these products are expensive—$100 or more for a single bottle.
Also, because young children have thinner skin, they are more susceptible to absorbing these chemicals through the scalp and to the side effects that they might cause, such as skin or eye irritation, burning, and dryness.
Skip products containing lindane and malathion, our experts say. Lindane is neurotoxic and carcinogenic to humans, and it has been linked to reports of seizures and even deaths from improper use. Malathion hasn’t been proved safe on children under 6 years. It’s also highly flammable and in some cases can cause stinging and chemical burns.
Non-Pesticide Over-the-Counter Products
To address the problem of pesticide resistance in super lice, some companies have introduced products that claim to get rid of lice without pesticides.
One such product, Nix Ultra, includes a lotion made with dimethicone, which smothers lice. Another product, which is available in Canada, Resultz, uses the ingredient isopropyl myristate, which dissolves the bugs’ exoskeletons and dehydrates them.
What to know: These products aren’t pesticides, so lice are unlikely to adapt to become resistant to them. The active ingredients are common in a variety of cosmetics, and they’re unlikely to pose major risks, so these are reasonable options for people to try—just remember that even with these products, combing is likely to be involved (in the U.S., dimethicone as a lice treatment is sold as part of a kit that also contains a lice comb).
You might have heard of home remedies for getting rid of lice, such as the application of mayonnaise, oil, or petroleum jelly. Some of these alternative treatments rely on suffocating or drowning lice.
What to know: The research on these options is slim, but some evidence suggests they may not be very effective. In one 2018 study, researchers subjected lice in a lab to suffocation and submersion in water. The scientists found that 100 percent of tested lice survived 8 hours in a sealed container without oxygen and 6 hours immersed in water. Many were able to survive under those conditions for much longer.
Gangloff-Kaufmann says that these types of treatment are often left on hair overnight, covered with a shower cap or plastic bag to keep the mayo or oil from getting everywhere. But this can pose a choking hazard, she notes.
Focusing your efforts on wet combing is likely to be a better bet.
Hot Air Treatment
At the lice treatment chain Lice Clinics of America, you can receive treatment with a hot air device called the AirAllé. The company guarantees elimination of nits and lice in one treatment.
What to know: We couldn’t find much evidence of the treatment’s effectiveness beyond the studies that the device’s inventors have published. Those studies do show promising results. Still, the treatment can be pricey—it varies by location, but we found clinics that list the price of this “signature” treatment as $175 to $199.
Additional reporting by Catherine Roberts.
Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Copyright © 2019, Consumer Reports, Inc.
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