Dr. Claire McCarthy is a primary care physician and the Medical Communications Editor at Boston Children’s Hospital. Along with her blogs here on Thriving, you can find her at the Huffington Post and Boston.com. Follow her on Twitter @drClaire.
Around 10 years ago, my family got head lice—and I thought we might have them forever.
I will never forget it. My head had been itchy for a while; I tried dandruff shampoo but it didn’t help. One day, desperate with itching, I asked a colleague at work if she’d check my scalp for me. “Claire,” she said, “you’ve got head lice.” I called home, and told my husband to check himself and the kids. They were infested too.
By the time I got home, my husband had bought permethrin cream rinse and treated everyone. I immediately globbed the stuff on my scalp for the allotted time and used the little plastic comb in the box, combing out some of the nits (and lots of creepy-crawly black bugs). We washed all the bedding and clothes, scrubbed all the brushes and combs, tossed the stuffed animals in the dryer. We were relieved—but within a day or two, it was clear that we were still infested. A week later, according to the instructions (and what I’d learned in medical school), we did it again—to no avail. Those bugs were undaunted; they had no intention of leaving our heads.
Our experience is becoming remarkably common. Head lice have been around for thousands of years (they’ve been found on Egyptian mummies); they are strong, resourceful little buggers, and develop resistance to chemicals used to get rid of them. Which doesn’t mean you shouldn’t try pyrethrin or permethrin, the treatments you can pick up at the drug store; it just means that you shouldn’t be surprised if they don’t work.
We get head lice from other people with head lice—head-to-head contact does it best, but they can also be spread by shared combs, brushes, hats, or other head accessories. They can hang out on bedding or upholstered furniture for a short time, so it’s easy for them to spread within a household. While they don’t fly or jump, kids at school (especially preschool or elementary school) often get close enough and share things enough that outbreaks are common. And until they are gone from everyone, they can keep spreading. Each female louse lays around 100 eggs, that hatch eight days later; once those lice start laying and hatching, well, you can imagine the math (I’m getting itchy again writing this!).
So it’s not surprising that people would go looking for stronger and better cures for head lice, and this month there was a study published about two of them: malathion, an insecticide, and ivermectin, an antiparasitic drug. The researchers used them on people who still had head lice two to six weeks after using permethrin or pyrethrin (my family would have qualified!), and found that 85 percent of the malathion group got rid of their lice, and 92.5 percent of the ivermectin group got rid of theirs.
Sounds great, right? Well, there are two problems to consider. First, as we’ve said, head lice are resourceful creatures. If we start using these treatments frequently, it’s likely that the lice will begin to be resistant to them (the researchers were careful to point out that these treatments should be reserved for cases where nothing else has worked). Second, and more importantly, both malathion and ivermectin can be toxic—usually just if used incorrectly, but even correct use could cause side effects in some people.
So what do you do if your child (or your family) has lice? There are lots of remedies out there, most of which don’t work or are dangerous (and some of which, like petroleum jelly, can be very messy). The Harvard School of Public Health has lots of great information on remedies (and on head lice in general), but what I recommend, and what ultimately did the trick for us, is the simplest treatment of all: combing. It’s not a quick fix, but it works. Here’s what you need to do:
- Buy a good lice comb, one with long, metal tines that are very close together (drug stores and pet stores sell them).
- Get out any tangles before you get started, or the lice comb will just get stuck. Detangling spray can help; if you do the whole thing in the tub, putting conditioner on the hair helps the comb go through (and you can rinse out the conditioner afterward).
- Separate the hair into sections. Start at the scalp where the bugs and live eggs are, and comb through to the end. Rinse or wipe the comb after each pass (check to see what you got first).
- Comb every day until you haven’t seen any eggs or live bugs for at least eight to 10 days (since that’s how long it takes an egg to hatch).
Not only is this approach completely non-toxic, if you go at it with the right attitude (i.e. a fun and patient one), it can be quality family time! Try telling stories (you can take turns adding to them) or making up songs—or just use it as a time to catch up and find out what’s going on in your child’s life. That’s what we did, and after two weeks of bonding—I mean combing—we were finally lice-free.