Lice in 25 States Resistant to Over-the-Counter Treatments

Scientists found in new research that head lice populations in 25 states are resistant to the active ingredient in many over-the-counter treatments recommended by doctors and schools.

Dr. Kyong Yoon, a researcher at Southern Illinois University at Edwardsville, in a press release said, “We are the first group to collect lice samples from a large number of populations across the U.S. What we found was that 104 out of the 109 lice populations we tested had high levels of gene mutations, which have been linked to resistance to pyrethroids.”

Yoon collected lice from 30 states, analyzing them for knock-down resistance, or kdr, mutations.