How to (calmly) deal with head lice

A tiny, relatively harmless pest, head lice is greatly feared among parents of young children. It's understandable: something about creepy crawlies hiding in your hair is unsettling. By the time you're done with this article, you'll probably feel phantom tingling on your scalp and a sudden urge to scratch.

According to estimates from the Centers for Disease Control and Prevention, six to 12 million children ages three to 11 get lice every year. My own family has battled lice twice. Both times I became infected after a child climbed into my bed at night and shared my pillow. I spent hours dragging lice combs through my children's hair, visiting a local hair salon where the stylist was known – through quiet word of mouth – to comb out lice after hours, and even once paid for a home visit. All told, I spent over a thousand dollars delousing my family.

However, according to experts, this was not necessary. Although head lice are contagious, they are not hardy or resilient. You don't have to light a campfire of sheets and stuffed animals to rid your house of them.

Here's how to identify and treat an infestation.

How do you know it's head lice?

Lice can be easy to miss. Adults, which are grayish-white and the size of a sesame seed, are most active at night and hide from light. “A person with an active infestation may only have ten adult lice on their head, and they grow up quickly,” says Dr. Laura Melnick, assistant professor of clinical dermatology and pediatrics at Weill Cornell Medicine in New York. Nymphs, the baby lice, look similar but are smaller. Eggs or nits are what you usually find during a home inspection. “Imagine tying a knot in a thread – the nits are the size of that knot” and lie within an inch of the scalp, said Dr. Candace Johnson, assistant professor of pediatrics and hospital epidemiologist at Columbia University.

The best places to check for eggs are behind the ears or on the nape of the neck, where individual hairs are easier to isolate.

You can tell lice from dandruff or seborrheic dermatitis – an itchy skin condition – because dandruff flakes brush away (eggs don't) and dermatitis causes crusting on the scalp.

I found nits. What now?

Remember: lice are annoying but harmless. “They don't transmit disease,” said Dr. Johnson. “And it's a myth that they are linked to poor hygiene. They are just a nuisance.” Start by checking on everyone in the family. (Pets cannot get lice from people.) The pests are transmitted through direct contact. Therefore, young children who curl up on classroom carpets like puppies are most susceptible. They can spread through shared hats or hairbrushes, but that is less likely. “Lice don't fly or jump – they crawl,” said Dr. Johnson.

Then it is time for treatment. Over-the-counter products such as Nix and Rid that contain permethrin or pyrethrins can kill adult lice. Follow the instructions: Lice have a two-week life cycle, so you should apply the products twice, about a week apart.

These ingredients are approved by the Food and Drug Administration: permethrin for children 2 months and older, and pyrethrins for children two months and older. Another product, called Sklice and also sold under the generic name ivermectin, is approved for children 6 months and older.

For parents concerned about applying harsh chemicals to young heads, doctors have reassurances. You only use the products for a short time, and “they are researched and safe,” says Dr. Justine Fenner Biederman, assistant professor of dermatology and pediatrics at Mount Sinai Icahn School of Medicine.

Occlusives – thick, water-repellent substances such as mayonnaise or lotion – can kill lice, although doctors emphasize that these DIY treatments have not been well studied. If you choose this route, Dr. Melnick recommends 100 percent petroleum jelly (Vaseline), which does not cause allergic reactions.

What about combing?

Creams and shampoos cannot kill the eggs, so your child may still get nits between treatments. Combing is the only way to remove them. “There is no need to prevent the spread because nits don't move,” said Dr. Melnick. But waiting while you know there are still eggs can be nerve-wracking. And some schools won't let kids come back if they still have nits the CDC. and the American Academy of Pediatrics both recommend against a no-nit policy.

You will need a fine-toothed metal comb designed for removing lice. Start with wet hair and go through small sections. Repeat the process every two to three days for two weeks, remembering to still use medicated cream as directed. Any nits missed during combing can hatch, leaving you back at square one if left untreated.

For parents who want to leave it to the professionals, there are lice removal boutiques in some cities, where trained technicians will comb through your child's hair. This service typically costs hundreds of dollars.

How do I thoroughly clean my house?

Wash sheets, towels, hats, clothes and jackets in warm water and dry on high heat. Adult lice can't stay outside the human head for more than a day or two, so there's no need to wash T-shirts that haven't seen the light of day in a month. If your child's cuddly toys cannot go through the washing machine, put them in a plastic bag for two weeks. Be sure to vacuum couches, rugs, and car seat headrests.

Is there a magical way to prevent lice?

Preventative shampoos exist, but there's no research showing they work, and the essential oils in them can cause irritation, said Dr. Fenner Biederman. Braiding or tying up long hair that lice can crawl into can help and certainly can't hurt.

If there is a lice outbreak in your child's classroom, start checking, but again, don't panic.

“Most children exposed to head lice will not get it,” said Dr. Melnick. “It may not feel like it, but it's the truth.”