Head Lice

Children and Lice – What to Know

Anyone who has children in school or in daycare can identify with the panic that parents feel when that call comes from the school nurse or the note comes home in their child’s backpack that their son or daughter has head lice. Head lice has always been more common in situations where people are grouped together, including schools and summer camps, but lately there has been increasing attention in the media warning about “resistant” head lice, which makes this routine problem seem more serious.

In fact, there are increasing numbers of reports of head lice that have become resistant to some of the first-line, over the counter products that are available to families. The good news, however, is that there are also several prescription products which can circumvent this issue and should still be effective even against resistant head lice.

One of the biggest challenges in the treatment of head lice is distinguishing between an active case and old, fully treated infections where the lice’s empty egg cases, also known as “nits”, remain stuck to the hair shaft but are no longer living or contagious.

How are lice spread from one person to another?

The most common route of spread is through direct head-to-head contact; less commonly it can also occur when children share hats, pillows, combs, or hair brushes. The American Academy of Pediatrics does NOT suggest avoiding important head protection like helmets due to concerns of head lice, however.

How can I prevent my child from getting lice?

It may be impractical to believe that lice is 100 percent preventable in young children who play closely with one another, but ways to minimize your child’s chances of contracting lice include teaching your child not to share combs, brushes, or hats with others and checking your child’s scalp regularly to rule out any problems. When cases do occur within a school or camp, prompt treatment can decrease spread to others.

How do I know if my child might have head lice?

Inspect the “high-yield” areas, which are the scalp at the nape of the neck and behind the ears within 1 or 2 mm of the scalp, to look for white flecks that are moving. Children usually develop itching, especially after several days of infestation, but if it’s the very first case of head lice they may not become allergic to the lice’s saliva for a full 6 weeks, so the absence of itching does NOT fully rule out a live infestation. Beware, because other common skin problems such as dandruff or dried hairspray droplets can appear similar to lice, these do not move.

How can I tell if my child has an active case of head lice or just leftover nits?

An easy rule of thumb is that if the nit is much more than 4 mm away from the scalp, it is less likely to be alive. This is because most living head lice lay their eggs within 1 to 2 mm of the scalp, since they depend on both the warmth and the blood supply of the scalp to remain alive.

What should I try first-line to treat head lice?

First, ensure that what you are considering treating is truly an active case of head lice and not dandruff or empty egg casings from a previously successfully treated case of lice. The following is a list of over the counter first-line agents for treating head lice:

• Permethrin 1%
• Pyrethrins Plus Piperonyl Butoxide

Are there any non-medical or “natural” approaches I can try to treat my child’s head lice?

No well-done studies have properly evaluated the efficacy of products such as mayonnaise, butter, or olive oil for treating or “suffocating” head lice. The safety and efficacy of herbal products is unknown, as they are not currently regulated by the Food and Drug Administration (FDA), so these agents should be avoided in children due to unknown risks.

If your child does not respond to one of the over the counter products and your doctor determines that an FDA-approved prescription product is indicated, options include:

• Malathion 0.5%. Please note this agent is flammable so avoid an open flame when applied. This is FDA-approved for children over 24 months.
• Benzyl alcohol 5%. This is FDA-approved for children over 6 months.
• Ivermectin 0.5%

Are there any products I should absolutely avoid in treating my child’s head lice?

Lindane 1% is no longer recommended for treating children’s head lice due to concerns of absorption and potential neurotoxicity, including seizures.

Products that we NEVER recommend include gasoline or kerosene.

What should I do if it doesn’t seem to be getting better? Does it automatically mean my child has “resistant” head lice?!

The first things to consider in a case of head lice that seems like it isn’t getting better is whether there could be another diagnosis, such as dandruff or psoriasis, that could explain the findings. Consult your pediatrician or pediatric dermatologist to help with this consideration.

Make sure if you are treating active head lice that you have used enough of the medication and fully saturated the hair. Also, make sure that your child isn’t getting re-exposed to someone else who may be re-infecting him or her.

Lastly, you can entertain the possibility that the head lice may be resistant to one of the first-line over the counter therapies and may require a prescription therapy from your doctor.

For more information or to schedule an appointment with one of our pediatric dermatologists at UPMC Children's Hospital of Pittsburgh, please visit www.chp.edu/our-services/dermatology.