A lot of what you think you know about head lice is probably wrong. That may be because, if you have school-age children, you learned these head lice “facts” during a phenomenon I call “head lice panic.
The panic happens after one child gets head lice, and the parents of that child’s classmates or playmates are notified. The first stage of head lice panic consists of the repeated checking of your child’s scalp for any tell-tale signs of a nascent infestation (a.k.a., “looking for bugs”). No harm done there. But the second stage is the sharing of “folk wisdom” about what causes head lice infestation, how to prevent it, and how to treat it. But you’d be wise to ignore those folks (and their wisdom).In the interest of replacing folklore with facts, I asked experts to weigh in on nine widely-held beliefs about head lice and kids.
Belief: Children with dirty hair are more likely to get head lice.False. “It is definitely a myth that children with dirty hair are more likely to get lice,” says Dr. Shelley Cathcart, a pediatric dermatology fellow at the University of North Carolina School of Medicine. “Lice infestations happen to everyone, regardless of cleanliness.”Belief: Children with curly hair are more likely to get head lice.False. “Lice cannot lay eggs if your hair is too curly” for them, Cathcart says, such as with African-American children, who have lower rates of head lice infestation.
Belief: Children with long hair are more likely to get head lice.False, unless you consider anything longer than stubble to be long hair. “Lice need about 1 centimeter of hair to lay an egg,” Cathcart says. “Any shorter than that and they are unlikely to infest a child. Shoulder-length versus chin-length [hair] should not make a difference.” And studies on hair length and head lice got mixed results – so don’t bother cutting off your daughter’s ponytail to protect her from head lice.
Belief: Children are more likely to get head lice during the summer.Probably false. “The incidence of diagnosing lice infestation goes up in the first months of school,” Cathcart says. However, she notes that this is likely because people are checking more closely.“Since lice can be spread through hats or jackets, the cooler months may bring along more lice,” says Dr. Debra Best, an assistant professor of pediatrics at Duke Children’s Primary Care. “However, they are unfortunately present throughout the year.”Belief: Head lice can spread disease.False. According to the U.S. Centers for Disease Control and Prevention, head lice are not vectors for disease or infection.
Belief: Rubbing tea tree oil in your child’s hair will prevent them from getting lice.Unclear, but you probably shouldn’t use it. While there is some evidence that tea tree oil may be effective at preventing lice infestation, “more research is needed before official recommendations can be made,” Best says. Should you try it anyway? “I would definitely not recommend it,” Cathcart says. “It is a common cause of contact allergy, [causing an] itchy rash, and more frequent applications of such substances could make it more likely that a child will develop the allergy.” Also, Best adds, “it should be avoided in those pregnant or breastfeeding.”Is there anything you can do? Yes. “The risk of getting lice can be decreased by not sharing hats, combs, brushes, and hair bows or clips,” Best says. “Keeping coats hanging separately from each other can help as well.”
Belief: You can treat head lice by washing your child’s hair with mayonnaise or Listerine.Mostly false. “Olive oil, butter, petroleum jelly, and mayonnaise have been used in the hopes of suffocating the lice. However, a small study showed that they did not help,” Best says. Lavender, hibiscus, and American paw paw are other popular folk remedies, but Best says that evidence for their effectiveness is insufficient.Cathcart notes that thick substances, such as mayonnaise or petroleum jelly, may suffocate adult lice. But because those substances wouldn’t kill the eggs, they aren’t a reliable way to treat an infestation.Wetting the child’s hair and using a lubricant such as olive oil or vinegar is often recommended for the “wet combing” technique for removing lice and eggs. But again, it’s not clear whether this is effective. “Studies looking at the effectiveness of wet combing have been equivocal,” Best says. One study found wet combing to be only half as effective as using a topical treatment to kill the lice while another study found that wet combing was more effective than the topical treatment.
Belief: The only medical treatment for head lice is lindane, which is extremely toxic.False. “Lindane is no longer commonly used because of neurotoxicity concerns,” Cathcart says, and Best agrees. “There are so many other treatments that I don’t really even consider lindane when I am deciding on therapy,” Best says.What are those other treatment options? Permethrin and pyrethroids with piperonol butoxide are available over the counter as topical rinses (for example, in the products Nix and Rid). Prescription treatments include malathion lotion, spinosad solution and ivermectin lotion. The prescription treatments are applied topically and should be repeated 7–10 days after the first treatment. But these treatment options “are safe if used as prescribed or suggested on the product label,” Cathcart says.
Belief: To prevent the head lice from coming back, you should fumigate or throw away your child’s pillowcase, stuffed animals, etc.False. “Any clothing – even jackets and hats – bed linens and towels used within two days before treatment should be washed in hot water (at least 130°F) and dried on the hottest setting possible,” Best says. “Lice cannot live off the body for more than two days, so items used prior to this time are unlikely to contain lice. Furniture, carpet, draperies and other things that cannot go in the washing machine can be vacuumed – and then throw the vacuum bag away. Items that cannot be washed should be sealed in an airtight container or plastic bag for two weeks. Combs, brushes, and hair clips can be washed in hot, soapy water.”But the most important thing is to notify your child’s school or daycare. “If your child has lice, then he or she most likely got it from another child at the school,” Cathcart says. “If you don’t tell the school for fear of embarrassment, then your child will continue to be reinfected by classmates whose infestation goes unrecognized and therefore untreated.”And don’t hide your newfound knowledge about head lice. Sharing accurate information can spare parents and children a lot of worry and wasted effort. Why rub mayonnaise into your child’s hair if you don’t have to?
[Matt Shipman is a freelance writer (and father of three) in Raleigh, NC. You can follow him on Twitter @ShipLives.]