Responding to Increasing Treatment Resistance in Head Lice

In March of 2016, researchers from the University of Massachusetts–Amherst published a study that drew widespread attention from both the medical and parenting communities. The study found that sites in 42 of 48 states in the US had head lice with an average of three or more mutations that made the lice resistant to a popular type of head-lice treatment. The results imply that the vast majority of head lice in the United States can no longer be treated by conventional means, but what does that mean for you or your child with lice? Thankfully, you should still have options with the help of head-lice treatment experts. 

How Do Lice Develop Resistance? 

All organisms change and adapt to their environments over the course of many generations, with the most successful genetic traits tending to be passed down to more offspring. Although this process can be difficult to notice among long-lived humans, lice have many more opportunities to mutate and test out new genetic combinations within the same period of time. Because of this, short-lived creatures like bacteria and insects are able to develop resistances to specific substances in as little as a few years or decades, with the most resistant organisms surviving to pass on the trait to their children. It appears that lice have finally adapted to resist one of the most common over-the-counter lice treatments in use today. 

What Are the Lice Resistant to? 

The treatments in question use chemicals called permethrins and pyrethroids, which work by attacking the brains of insects and similar animals. Many insects have already developed a resistance to these chemicals, a phenomenon known as knockdown resistance. As the effectiveness of permethrins and pyrethroids diminish over time, medical professionals and parents will need to find new ways to combat lice that they are not so well prepared for. 

How Can You Treat Resistant Lice? 

The good news is that these particular insecticides are not the only way to kill lice. You can still find success with several different treatment methods, including prescription treatments that are controlled more carefully to prevent lice adaptations. Other treatments are more physically based, such as making the hair more slippery to facilitate combing lice out by hand. If you have been trying to get rid of your child's lice with grocery-store products to no avail, try contacting head-lice treatment experts to get recommendations on more effective treatments to try instead. The only way to stay ahead of lice is to adapt faster, so make sure you are staying at the cutting edge of head-lice treatments.