September 28, 2015

Head lice treatments

The kids are back in school, which means there's a chance you may soon be receiving that dreaded note — lice have been found in the classroom. Coupled with news reports that say scientists have found "super lice" resistant to treatment, it can seem rather frightening.

While we're still learning what the recent research means, the good news is that there are still treatments available. And while it can seem daunting at first — believe me, I've experienced it with my own family — lice can be treated successfully, it may just take a little patience and work. Let's start with the basics.

About lice

Lice are small gray to white insects that are specific to humans that affect the scalp and skin close to the scalp. While they cause itching which can be intense, they do not carry diseases and do not pose a health threat to humans. They crawl — they cannot jump or fly which means they can only be transmitted by very close scalp contact or by sharing "head gear," i.e. hats, combs, brushes, pillows, headphones.


The most common over-the-counter topical treatments are pyrethroids. These act as neurotoxins to the lice but are very safe for humans, which is why we have used them so extensively. The problem is that now we are facing a situation where a huge percentage of the lice now carry resistance genes for this medication. One group of scientist that has looked at lice from 30 states has found that all of the samples taken from 25 of these states carry two copies of the resistance gene (kdr) suggesting that they will not respond as well to pyrethroids. What we don't know yet is how this will play out clinically.


While treatments using pyrethroids may not be as effective as they once were, they certainly still work for some people. And, other medications are still very effective at killing lice, but we do need to be careful with how we use these alternatives so we don't end up with the same situation in terms of resistance. Alternatives to pyrethroids do require a prescription.  These include:

  • Malathione

  • Ivermectin

  • Spinosad

  • Benzoyl alcohol

One sure fire way to treat lice is to shave your hair — no hair, no lice!  However, this is not necessary and may not be practical for most people.

What does this mean for families?

If your child has lice, you will see live lice or nits within a quarter-inch from the scalp. When you see these signs, you can start with an over-the-counter product, but make sure you follow instructions carefully. General instructions for all topical anti-lice treatments:

  • Wash hair with shampoo (no conditioner) and towel dry

  • Saturate the scalp with the product — make sure you use enough!

  • Leave on for a full 10 minutes (or as instructed by product)

  • Rinse off well

  • If the product is not effective at killing eggs, repeat in seven to 10 days

  • Combing the hair with a nit comb helps to remove the nits and can be done daily to every other day after treatment

If this does not work, check with your doctor who can prescribe one of the other effective treatments.

At-home remedies

With a quick Internet search, you can find many at-home products that people use to treat lice such as olive or almond oil. With many of these methods, the idea is to suffocate lice, but the treatment may not be effective. In order to suffocate the lice, the product must be left on for eight to 12 hours and requires frequent applications and treatments. If I were going to go this route, I would try Cetaphil Cleanser or petroleum jelly.

You may also see products on the store shelves that claim to prevent lice infestations. One in particular is a product called Rosemary Repel shampoo and conditioner. It contains rosemary, citronella, tea tree and geranium oils. Similarly, you can also find recipes online for essential oil combinations to spray on the hair and scalp. Apparently, lice do not like these oils and theoretically will not make themselves at home in their presence.  While evidence supporting use of these essential oils is inconclusive, it certainly won't hurt. If you have questions or concerns, please talk to your primary care provider.