Your feeble weapons are no match for today’s mutating head lice

Generally considered a nuisance because they don’t carry disease, lice can still be controlled using different chemicals found in prescription treatments.

Parents could be implementing the feared “lice check” more than everyday this college 12 months as off-floor remedies seldomly look to be at the office, according to new research to be reflected for the National Meeting & Exposition along the American Chemical Society on Tuesday. The first such case of lice insecticide-resistance was reported in Israel in the late 1990s, for instance.

“We are the first group to collect lice samples from a large number of populations across the U.S.”, said Dr. Kyong Yoon, a researcher at Southern Illinois University at Edwardsville, in a press release.

Pyrethroids-a family of insecticides including permethrin, the active ingredient in common lice treatments-kill insects by latching onto receptors in their nervous systems.

Lice populations in the states in pink have developed a high level of resistance to some of the most common treatments.

Evidence of widespread pyrethroid-resistant lice has been building for years. The genetic mutations called kdr (“knock-down resistance”) had initially been identified in house flies in the late 1970’s after farmers began to use pyrethroids from DDT and other harsh insecticides. The samples that showed kdr came from California, Texas, Florida, Maine and 21 others.

Having all three genetic mutations means that these lice populations are the most resistant to pyrethroids. Samples from four states, including New York, New Jersey, New Mexico, and Oregon, had one, two, or three.

In the most recent study, Yoon gathered lice from 30 states with the help of public health workers.

“It’s a really, really serious problem right now in the U.S.”, Yoon says.

So what’s a parent to do?

These newer medications are sold as Natroba (spinosad 0.9% topical suspension) and Sklice (ivermectin lotion, 0.5%), respectively. But over the years, Yoon said, lice have evolved in such a way that the chemicals no longer fit neatly into the receptors, thereby squashing the chemical’s bug-killing ability.

With the return to school on the horizon, parents will be anxious to learn that new research suggests that head lice have developed a “high level” of resistance to some of the most popular treatments. (“My PhD entirely focused on head lice”, he says with a laugh.) Using the services of professional nitpickers across the country, Yoon decided to take an American lice census by collecting pest populations from every state.