Disease & Illness

Treatment-Resistant Head Lice Have Been Found In 48 States—Now What?

One study found nearly 100% of head lice collected were resistant to over-the-counter treatments.

If you’re a parent of elementary school-aged children, you’re going to want to read this: Evidence from a study published in 2016 shows that 98 percent of head lice in 42 U.S. states are now resistant to over-the-counter treatments like Rid and Nix.

Yep. Go ahead and shudder. As the parent of young kids, I’m right there with you.

Researchers tested lice collected from 48 states (the only states without testing sites: Alaska and West Virginia) over the course of a two-year period from 2013-2015. What they found was that nearly 100% of the head lice collected were resistant to over-the-counter treatments. Those states with samples not at 100% weren’t far behind: North Dakota and New Mexico had resistant lice in 50-99% of cases, and Michigan, New York and Oregon had “mixed results with some sites at 100 percent and others with less.”

Now here’s the big caveat: Yes, the lice have been found to be “resistant” to treatment, but no, that doesn’t mean the traditional over-the-counter treatments are completely ineffective. What this does mean is that it may take a second or more aggressive treatment to kill them.

As Dr. Robin Gehris, chief of pediatric dermatology at the University of Pittsburgh, told Today: “Treat the entire head and leave it on for a few hours and then repeat a week later.” If you still see evidence of lice after a second treatment, Gehris suggests calling your doctor. Many lice-killing treatments (technically called “pediculicides”) are meant to be removed after 10 minutes, so be sure to double-check with your own doctor before leaving it on for hours, as Gehris suggests.

There’s a second caveat to this story, too: A pharmaceutical company that makes prescription head lice treatment contributed funding to the research. While it’s unlikely this influenced the data collection and ensuing results—that lice have mutated to become more resistant to the insecticides traditionally used to eradicate them—it does mean some of the treatments the study participants suggest (to skip the OTC treatments and go straight to prescribed options instead) may be partially biased.

All that said, if hats are exchanged or brushes shared at school this year and my child ends up with head lice, I certainly will be calling our pediatrician to hear about her recommended course of action. And if there’s a prescription-strength treatment that will knock out the lice the first time we use it, consider me signed up for that.

Here are a few fast facts about treating head lice:

  • Lice are about the size of a sesame seed.
  • The most common places to find them are behind the ears and at the nape of the neck.
  • Lice should respond to treatment within 8-12 hours after application.
  • Continue to check your child’s head for 2-3 weeks after initial treatment to ensure no new eggs have hatched.
  • Symptoms of head lice include itching or experiencing a “ticklish” feeling on your scalp, though some people have no symptoms at all.
  • While a lice infestation is disturbing and can cause a sore, itchy scalp as well as extra work to get rid  of them—that’s generally about the worst of it.
  • Lice can’t jump or fly, so head-to-head contact or using an infested pillowcase, hat or brush are some of the common ways they migrate.
  • Lice can’t live for very long off of a scalp. If your child does have lice, it’s recommended to wash all bed sheets, clothing or stuffed animals that they’ve been in contact with within the last 48 hours. Items that can’t be washed can be dry cleaned or kept in a plastic bag for two weeks. Read more about treatment on the CDC’s website.

Photo by Gilles San Martin