Head Lice Getting Ahead of Treatments, Officials Fear

To parents recoiling from the discovery of lice on their child’s scalp--which is dismayingly common and getting more so, health officials say--the latest word from the medical front offers little comfort.

Ordinary head lice may be turning into “super lice,” developing immunity to over-the-counter treatments that are parents’ chief weapon.

The California Department of Health Services warned in a 1996 report that there is “circumstantial evidence” of increased head lice resistance. This could explain why some public health officials are seeing a dramatic rise in lice outbreaks.

“I’d say we have a 20% to 30% increase in the number of calls in the last year,” said Dr. Vicki Kramer of the Department of Health Services, who works with public schools and health departments on head lice.

“If the lice are harder to get rid of, people are carrying them for longer periods of time. And that increases the chance they will infest someone else.”

Neither school districts nor federal and local health officials keep statistics on head lice, regarded by medical officials as a nuisance rather than a disease.

Scientific studies on the possibility of immunity have not been completed in this country, and some health officials blame increased infestations on improper use of remedies. A group of Israeli researchers, however, say their tests have proved that head lice, which medical historians trace back 9,000 years, are overpowering over-the-counter treatments.

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Some parents do not need to be convinced. “We tried everything we were supposed to do and we still could not get rid of them,” said Robin Fried of Agoura Hills, whose 6-year-old-daughter was sent home from school with head lice in November.

“We tried the shampoos the school nurse told us we could find in the drugstore. We would think we got rid of all the eggs, but then we would take her back to school and they would examine her and say there were more.

“I was hysterical. I thought we would never get back in,” said Fried, whose daughter missed five days of school.

Colleen Baum, whose daughter attends kindergarten at a private school in Encino, is a veteran of the head lice wars. The girl has been sent home twice with lice.

“I’ve become the neighborhood expert,” says Baum, who adds that she knows other parents who repeatedly use lice treatments, ignoring instructions not to do so.

“Other parents are bringing their kids to me. I tell them the only thing you can do is to make sure you manually pick out every single egg. The treatments might not get them all; then they can hatch and you start all over again.”

School and health officials said the childhood infestations are chronic in California and around the nation, especially at the start of school terms.

“It happens to everyone,” said Dr. Carol Peterson, a medical epidemiologist with the Los Angeles County Department of Health Services. “It’s an old myth that head lice is related to socioeconomic status.”

In Irvine, a lice outbreak at one elementary school infected 37 students and one teacher last fall, said Irvine Unified School District nurse Sally Valentine.

One student’s problem was so severe he missed 25 days of school.

“Some kids keep coming back with lice,” Valentine said, “and their parents are apparently religiously trying to treat the situation.”

A couple of years ago, public health offices started receiving complaints from school health workers that widely used remedies--pesticides approved for scalp use--weren’t working as effectively anymore.

“We’ve been getting reports from school nurses from all over the country,” said Terri Meinking, a University of Miami researcher who co-wrote a landmark 1986 report on head lice treatment. “When they say it doesn’t work the way it used to, we have to take that seriously.”

Los Angeles County health officials also suspect that resistant lice are to blame for persistent infestations.

“We have heard from reliable, apparently educated parents who describe to us how they are using the products,” Peterson said. “Their children are still having a problem with the lice after they do the treatments. But because we weren’t there, we can’t know for sure if directions were followed. It’s going to take a scientific study to nail this down.”

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Just such a study is underway at Harvard University. Dr. Andrew Spielman, a professor of tropical public health overseeing the project, said he hopes research into head lice resistance will be completed this fall.

In Israel, researchers found that head lice had developed a resistance to pyrethroids--the family of chemicals used in common remedies.

Pyrethroids are derived from chrysanthemum flowers, in which they act as natural insecticides. In 1986, a synthetic form, called permethrin, was approved by the U.S.Food and Drug Administration for head lice treatment.

Permethrin is the active ingredient in Nix, which drug industry officials say is the most widely used brand in the United States.

Israeli scientists blamed permethrin, in particular, for the resistance they found. “The results suggest that resistance to pyrethroids has developed rapidly among head lice since permethrin was introduced [in Israel] in 1991,” the researchers wrote in a report published in the British journal Medical and Veterinary Entomology in 1995.

The drug industry giant Warner Lambert, which makes Nix, disputed the Israeli findings.

The Israeli study tested only permethrin, the key active ingredient in Nix, but not the entire formula, which contains several substances, said Dr. Judith Sills, senior director of product safety surveillance and information at Warner Lambert.

When Nix doesn’t work, it’s because parents aren’t using it correctly, she said. “I don’t believe they demonstrated true resistance.”

But Spielman, whose research at Harvard also focuses on permethrin, said the Israeli work “looks like a reasonable study.”

Enough evidence has surfaced that at least one drug industry figure conceded that resistance is probably real.

“We have to assume there is growing resistance out there,” said Harry Upton, president of Care Technologies, which produces the Clear line of head lice treatments, “or at least an awful lot of misapplications.”

Like other public health agencies, the national Centers for Disease Control and Prevention has never tracked head lice outbreaks, said spokesman Tom Skinner. Though repugnant insects that feed on human blood, lice are not known to spread disease or cause serious injury. And for researchers, there is little glory to be found here.

“This is a non-glamorous, non-sexy field,” and few young scientists enter it, said Dr. Christine Hahn, Idaho’s state epidemiologist, who is working on the Harvard study.

“Researchers know they will get noticed if they make a breakthrough in cancer or AIDS. You could do the best research in the world on head lice, and you are not going to wind up with the Nobel Prize.”

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The drug industry has been more motivated to take head lice seriously. Last year, sales of Nix grew by 52% to reach $42 million, said Leslie Hare, a Warner Lambert spokeswoman. Hare said the increase is largely because of increased distribution and a successful marketing campaign.

That campaign has reached local school districts, including Los Angeles Unified. District officials say they don’t recommend products, but brochures sent home with students were donated by Warner Lambert and contain a Nix ad.

The head of a nonprofit group that distributes lice awareness information said she is concerned about aggressive marketing.

“The industry from the beginning has put out information that has caused confusion and the abuse of the chemicals commercially available for children who get lice,” said Deborah Alschuler, founder of the National Pediculosis Assn. (the Latin name for head lice is Pediculus humanus capitis).

“People perceive these products to be shampoos and cream rinses,” she said. “That sounds nice, but these are pesticides.”

Adults are so repulsed by lice they sometimes take dangerous measures.

“We still get reports of parents using kerosene,” said Lori Nelson, a Los Angeles Unified nurse.

Far worse, an Oklahoma City man tried to treat a 6-year-old girl by washing her hair with Diazinon, an agricultural pesticide, police there reported last month. The girl went into cardiac arrest and doctors say she may have permanent injuries.

When treatments don’t work, some physicians prescribe stronger doses of permethrin, a 5% solution rather than the 1% in Nix. But if lice are becoming resistant to the weaker solution, it is likely they’ll resist the stronger dose eventually as well, researchers warn.

Meinking, in Miami, said there is hope for the future from new louse-killers.

“We are working on new treatments that will have active ingredients that are not pesticides,” she said. “We are on the road to some very exciting things.”

Times staff writers Tina Nguyen in Costa Mesa and Kate Folmar in Ventura contributed to this story.

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Facts and Treatment

* Latin name: Pediculus humanus capitis

* Size: 1/6 to 1/8 inch long

* Legs: Six

* How spread: Head-to-head contact

* Myth: That they fly or jump

* Food: Blood

* Eggs: Female lays up to 10 per day.

If someone in your home has head lice, experts recommend these steps:

1. Try over-the-counter treatments such as Nix, Rid, Clear and A200. A physician or pharmacist should be consulted if the patient is pregnant or nursing, or has asthma or epilepsy.

2. Follow directions carefully and don’t overuse, even if lice persist.

3. Use a lice comb, baby safety scissors or fingernails to remove a lice eggs, known as nits. Nits are the size of sesame seeds; school health clerks recommend using a strong light to help spot them.

4. Wash bedding and recently worn clothing in hot water and dry in a dryer. Combs and brushes should be soaked in hot water. Head lice feed on blood and cannot survive for more than about 48 hours on soft surfaces such as bed linens and movie theater seats.

Sources: National Pediculosis Association and health officials.