‘Super Lice’ outbreak hits 25 states: Here’s what you need to know

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Lice populations in the states in pink have developed a high level of resistance to some of the most common treatments. Credit: Kyong Yoon, Ph.D.

Lice populations in the states in pink have developed a high level of resistance to some of the most common treatments. Credit: Kyong Yoon, Ph.D.

NEW YORK — An outbreak of “super lice” that is resistant to over-the-counter treatments has hit 25 states, including several surrounding New York.

Lice — and other insects — are increasingly becoming resistant to pyrethroids, the active ingredients in most over-the-counter treatments, according to Kyong Yoon, an assistant professor at Southern Illinois University—Edwardsville.

In the most recent study, the research team gathered lice from 30 states. Samples with all three genetic mutations came from 25 states, including California, Texas, Florida and Maine. Having all the mutations means these populations are the most resistant to pyrethroids.

Samples from four states—New York, New Jersey, New Mexico and Oregon—had one, two or three mutations. The only state with a population of lice still largely susceptible to the insecticide was Michigan.

The finding doesn’t mean you can’t kill lice with pyrethroids, Yoon said. But you will need a higher dose.

Here’s what you need to know:

What are super lice?
Same as regular lice, super lice are parasitic insects that can be found on the scalp, eyebrows and eyelashes of humans and feed on blood. Due to a genetic mutation, super lice are resistant to over-the-counter treatments used to kill regular lice.

What are the symptoms of super lice?
The symptoms of head lice include the feeling of something moving in the hair, an itchy scalp, irritability and difficulty sleeping. The difference between regular lice and super lice is the response to treatment. If you or your child still have lice after an over-the-counter treatment, they may have super lice.

How do super lice spread?
Super lice are spread by direct contact with the hair of an infested person, the CDC reports. Head lice move by crawling, but they cannot hop or fly. Lice can also spread by sharing clothing or hair accessories recently worn or used by a person with lice. Dogs, cats and other pets cannot spread head lice.

How can you treat lice and super lice?
The American Academy of Pediatrics recommends parents use over-the-counter treatments unless resistance has been confirmed in other cases in the community. All clothing, linens and toys should be washed in hot water. If the lice are treatment-resistant, a pediatrician can prescribe another form of treatment that has been proven effective against super lice.