In Battling Head Lice, Prevention Is Key, UF Researchers Say

Cindy Spence

Phil Koehler (352) 392-2484
Clay Scherer (352) 392-1901 ext. 119

GAINESVILLE—This is the season for reading, writing, arithmetic — and head lice.

University of Florida entomologists say the back-to-school time of year is when head lice are most commonly transmitted, and they urge parents to be on the lookout for the tiny hair hitchhikers.

What’s more, in research to test the effectiveness of many over-the- counter products that claim to kill head lice, scientists are finding that many such products are losing their effectiveness.

“Already we’ve seen that head lice are becoming much more difficult to control than they were several years ago with the products that are available,” said entomologist Phil Koehler, a researcher in UF’s Institute of Food and Agricultural Sciences.

“The concern is that the failures we’re seeing are due to head lice developing resistance to these products,” Koehler said. “Since they’ve been on the market for 20 years, that’s plenty of time for head lice to evolve and become resistant.”

If head lice shampoos and products fail, parents are left with manual removal of the tiny pests – and prevention – as the best means of keeping their children free of head lice, said Clay Scherer, a graduate researcher who works with Koehler and who consults with elementary school nurses.

From August to November, Scherer recommends, parents should inspect their children’s hair weekly because the head lice transmitted then result in widespread infestations by December and January. The National Pediculosis Association sponsors Head Lice Prevention Month in September to raise awareness about the issue.

Scherer says head lice are mostly a problem in school-age children because of their playful, affectionate behavior. That behavior provides opportunities for head-to- head contact, which head lice need to spread.

“Head lice don’t fly, hop, jump or run, so it takes head-to-head contact to get them,” Scherer says. “Small children touch, they bump, they take naps, they share baseball caps and combs, and that allows head lice to spread.” The legs of head lice end in claws that are very suited to grasping hair shafts and moving around. The tiny blood-suckers usually lay their eggs, called nits, near the root of the hair. The nits are about 1/16 inch long and an adult louse is about 1/8 inch long.

Scherer and Koehler say all the current over-the-counter products have the same active compound so if head lice are resistant to one of them, another brand won’t help. Some older head lice treatments have been taken off the market because of serious side-effects.

But while head lice are bothersome, researchers point out, they are not fatal. Their best advice to parents is to avoid dangerous, even deadly, home remedies. Scherer said one mother soaked her child’s hair in kerosene, combed out the lice and dipped the comb as she went into a pot of boiling water on a gas stove. The child’s hair caught fire leading to severe burns.

Other home remedies, such as coating a child’s hair with mayonnaise or Vaseline, simply don’t work.

“Head lice are not a public health issue; they tend to be more of a nuisance,” Scherer said.

Although head lice have never been shown to transmit disease, just the presence of head lice is considered a disease called pediculosis. As the head lice suck blood from the scalp, they inject their saliva into the wound. Repeated exposure to the saliva eventually causes an allergic reaction. A child with a persistent problem ends up with swollen glands and a lot of irritation caused by the infestation.

If children do get lice, Scherer says all clothing and bedding must be washed and dried on high heat to kill the lice and eggs. To guard against reinfestation from eggs that hatch later, toys such as stuffed animals should be sealed in plastic bags for two weeks.

And if lice make some parents want to tear their hair out, well, that may be the best cure. For boys, a shaved head will help and for girls, a very short haircut can help in locating and removing all the lice and nits.

Koehler recommends double-checking the instructions for over-the-counter creams, shampoos and lotions to be sure they are followed. But if the instructions are followed and the treatment seems not to work, Scherer suggests avoiding repeat treatments; the products are not mere shampoos but insecticides. Manual removal of lice and nits with a lice comb is time-consuming but effective.

Although head lice infest 10 million to 12 million people each year in the United States, there is still a social stigma attached to the problem, Koehler points out. In fact, the childhood slur, “you have cooties,” originally referred to head lice.

Parents, the two researchers say, are the key to detecting and preventing head lice.

“One of the concerns we have is that parents really don’t spend as much time looking for lice as they should. They expect the school to do that for them, and that’s really not going to happen,” Koehler said. “I’ve worked with several elementary schools, and they can have 600 kids coming back to school in September. The school health screening may or may not include a check for lice. So you just need to assume there will be children in your child’s class that are infested, and they will probably spread to your child.

“So checking your own child is the best precaution,” Koehler said.