|Head lice move across a nit comb. (Kevin Dyer/iStock)|
In the paper, North Carolina is among 25 states shown to have head louse populations that are resistant to the most commonly used head louse shampoo treatments, including pyrethrins and the pyrethroid insecticide permethrin. In 104 out of 109 lice populations already analyzed, the authors found high levels of gene mutations that make lice indifferent to these over-the-counter treatments. The team is still analyzing data from the other 25 states.
Researcher Kyong Sup Yoon, lead author of the study, points out that "Just one louse that manages to survive a pyrethroid treatment can live for up to a month and lay five eggs a day. Multiply that by an elementary school, a community, and soon you’ve got plenty of resistant lice.”
The good news is that there is no reason to panic. There are new, non-pyrethroid options available through your doctor. These products will likely be more expensive, however.
Regardless of what product you use, pay careful attention to head inspection and combing after treatment. Using two methods (insecticide plus combing) is almost always better than one method when it comes to controlling lice.