Lice can cause excessive itchiness on your scalp.
Kevin Dyer/Getty Images

  • Lice are mainly spread through head-to-head contact with other humans.
  • Children most commonly get lice, through activities like sleepovers, playing sports or on a playground, and sharing hats, hair accessories, or other clothes.
  • This article was medically reviewed by Sharleen St. Surin-Lord, MD, a board-certified dermatologist at Visage Dermatology and assistant professor of dermatology at Howard University.
  • For more stories go to www.BusinessInsider.co.za.

Lice are tiny, parasitic insects that often live on human scalps. They're not harmful to humans and they don't spread disease, but they can be itchy and annoying.

Children - especially preschool and elementary school ages - are most likely to get lice, says Richard Chung, MD, a pediatrician at the Duke University School of Medicine.

In fact, it's estimated that lice affect up to 6 to 12 million US children between the ages of 3 and 11 years old, according to the Centers for Diseases Control and Prevention (CDC).

Here's what you should know about how lice spreads and what you can do to prevent it.

How do lice spread?

Lice cannot fly or jump, so they must crawl between hosts. That's why social children who participate in sports, have sleepovers, or play on a playground are more susceptible.

Lice can also spread through:

  • Sharing clothes - like hats, scarves, or coats - with someone who has lice
  • Sharing hair accessories like bows and ribbons
  • Lying on a couch, bed, pillow, or carpet near someone who has lice

"The general belief is that the vast majority of cases are direct head-to-head contact and close contact," says Chung.

Chung adds that a person can have lice for four to six weeks without showing symptoms, so they can easily spread it to others without knowing.

How to know if you have lice

Lice are very small and difficult to spot. They have three different stages in their life cycle, which repeats itself about every three weeks:

  • Eggs (nits)
  • Babies (nymphs)
  • Adult (louse)

What do lice look like?

Lice eggs are easiest to spot.
hirun/Getty Images
Finding adult lice may be difficult, as they move quickly and avoid light, so locating the eggs fused to hair follicles may be easier.

Unhatched eggs will look yellow, tan, or brown, and hatched eggs will look white or clear. Hatched eggs are easier to spot than live ones - especially when hair grows longer and the egg case moves away from the scalp.

However, Chung says that your eyes aren't always reliable at spotting lice. In fact, the eggs are often mistaken for dandruff. The following symptoms can help you differentiate between lice and dandruff.

Symptoms of lice

The main symptoms of lice include:

  • Itchy scalp
  • Feeling something tickle, or like something is moving on your head
  • Difficulty sleeping due to head discomfort
  • Sores on the head caused by scratching

Although not everyone will experience these symptoms, scalp itchiness is one of the most common signs of head lice.

Lice can be itchy because our body has a slight allergic reaction when they bite our scalp. The louse injects their saliva under the scalp as they bite, which can cause irritation and thus the allergic reaction.

According to the CDC, scratches from lice can become infected with bacteria normally found on someone's skin, but it's not more common than usual rate of infections caused by broken skin.

How to prevent lice

To prevent lice, you should follow these practices:

  • Avoid head-to-head or hair-to-hair contact. Since lice cannot jump or fly, they spread from direct head contact such as hugs, group selfies, or sharing the same pillow.
  • Don't share clothing. Hats, scarves, sports uniforms, ribbons, or any clothing that might touch hair can spread lice.
  • Wash and dry clothes on high heat. Temperatures above 130°F (54 degrees Celsius) kill lice. You should use this high heat to wash and dry clothes, bedding, stuffed animals, or anything else that may have been shared with someone who has lice.
  • Clean shared spaces. You should vacuum the floor and any furniture where someone with lice has been around or on, including couches or chairs.

How to treat lice

If you do suspect that your child has lice, it is important to treat it immediately to prevent spreading the parasite.

Common head lice treatments include physical removal with specialised lice combs, as well as lice-killing medications like insecticidal shampoos. You'll need to talk with your doctor to confirm the presence of lice and determine the most effective course of treatment for your child.

If you're interested in purchasing some of these treatments, our colleagues at Insider Reviews have compiled the best products to get rid of lice.

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