Head lice Health Article

Definition

Head lice are tiny insects that live on the scalp. They can be spread by close contact with other people.

These lice only live in hair and occasionally eyebrows and eyelashes.

See also:

• Body lice
• Pubic lice

Alternative Names

Lice - head; Nits; Pediculosis capitis - head lice

Causes, incidence, and risk factors

Head lice infect hair on the head. They are easiest to see on the neck and over the ears. Tiny eggs on the hair look like flakes of dandruff. However, instead of flaking off the scalp, they stay put.

Head lice can survive up to 30 days on a human. Their eggs can live for more than 2 weeks.

Head lice spread easily. You can get head lice when you come in close contact with a person who has lice, or by touching their clothing or bedding. Head lice are more common in close, overcrowded living conditions. Lice spread easily among school children.

Having head lice does NOT mean the person has poor hygiene or low social status.

Having head lice causes intense itching, but does not lead to serious medical problems. Unlike body lice, head lice never carry or spread diseases.

Symptoms

• Intense itching of the scalp
• Small, red bumps on the scalp, neck, and shoulders (bumps may become crusty and ooze)
• Tiny white specks (eggs, or nits) on the bottom of each hair that are hard to get off

Lice on scalp and clothing may be difficult to see, unless the infestation is heavy. If you see something moving, it's called a louse.

Signs and tests

To see head lice, you need to look closely. Use disposable gloves and look at the person's head under a bright light. Full sun or the brightest lights in your home during daylight hours work well. A magnifying glass can also help.

Part the hair all the way down to the scalp in very small sections, looking both for moving lice and eggs (nits). Look at the entire head this way. Look closely around the top of the neck and ears, the most common locations for eggs.

Treatment is recommended if even one egg is found.