Head scratcher: The lowdown on lice

Grimacing young girl receiving a wet comb treatment for lice.

It’s a nuisance that carries a lot of stigma and often presents itself without warning. Head lice pose no threat to your physical health but the prospect of battling an infestation head on can seem like a difficult, tedious task.

Epidemiologist Wil Ng, North York General Hospital
Epidemiologist Wil Ng

While itching can be a classic symptom of head lice, there are other common signs, including inflammation on the scalp or near the hairline and small red bumps on the scalp, neck and shoulders.

Epidemiologist Wil Ng, part of the Infection Prevention and Control team at North York General Hospital, says once a lice infestation is identified, treatment should begin immediately.

“You’ll want to use a combination of pharmacological and non-pharmacological strategies (which include combing out lice and nits). First, treat those with active lice infestations, check anyone in your house and others in close contact, and treat everyone at the same time.”

Spotting lice

Arm yourself with a bright light for the best view of the scalp and hair. In and around bangs, behind the ears, and the nape of the neck are considered lice “hot spots.” While nits can be difficult to see with the naked eye, an adult louse can be spotted more easily, and is about the size of a sesame seed.

Treating lice can be tricky  lice eggs (nits) attach to the shaft of the hair about a quarter inch from the scalp and carry a glue-like substance, making it hard to rid hair of nits. And, some common lice solutions aren’t as effective as others, making lice more resistant to treatment.

“Some lice have gotten smarter and have developed a gene mutation that makes them resistant to some insecticides used for treatment,” says Wil. “However, it's important to understand that although some over-the-counter treatments may no longer be as effective as they once were, these first-line treatments still work the majority of the time when used correctly.”

Wil suggests buying a topical over the counter solution or contacting a lice removal company to treat head lice and advises against using natural alternatives like tea tree oil, mayonnaise, and hot air.

“There are a lot of misconceptions out there. There have been uncontrolled studies that look at unconventional treatments. The bottom line is there is no published evidence to show these are consistently effective, nor are there any trials on the safety of these home remedies.”

Lice prevention

Lice can survive on the head for up to 30 days and can stick to brushes, elastics, hair clips, towels and hats. Make sure no one in your home is sharing them with others. It’s also a good idea to keep longer hair tied back. Weekly checks can also help spot lice before they multiply (lice can lay close to 10 eggs a day)!

While they don’t carry or transmit disease, there’s still an "ick factor" associated with head lice. But it shouldn’t prevent individuals from carrying out day-to-day tasks.

If your child has lice, contact the school to notify them and learn about the policy for head lice.

5 myths about lice

1. Lice are attracted to dirty hair

Lice don’t discriminate and will latch onto both clean and not-so-clean hair, as long as they can hang on to and crawl along the hair.

2. Lice jump or fly

Lice are wingless insects and while they can’t fly or jump, they are fast crawlers and have the ability to travel 23 centimetres (or nine inches) per minute!

3. Washing or soaking your hair will kill lice

Lice are extremely resilient and according to some experts, can survive up to 24 hours under water.

4. Lice can be transferred to and/or from pets

Head lice thrive and survive on human blood, which is why pets aren’t at risk for catching, spreading, or transferring lice.

5. Cutting hair short is a quick fix

It may take longer to remove lice and nits on longer hair but cutting it won’t make a big difference. Lice prefer areas like the back of the neck or behind ears.

This article first appeared in the September 2019 issue of The Pulse.

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