Lice - Topic Overview
What are lice?
Lice are tiny insects that live on
humans and feed on blood. When a large number of lice live and multiply on a
person, it is called an infestation.
Three different kinds of lice
live on humans:
Head lice are usually found in hair,
most often on the back of the neck and behind the ears. Head lice are common in
preschool and elementary school-age children. Adults can get them too,
especially adults who live with children.
Pubic lice , also called
crabs, are usually found in the pubic area. But they may also be found on
facial hair, on eyelashes, on eyebrows, in the armpits, on chest hair, and,
rarely, on the scalp.
Body lice live and lay eggs (nits) in
the seams of clothing. The lice are on the body only when they feed.
What causes a lice infestation?
Lice spread easily
from one person to another through close contact or through shared clothing or
personal items (such as hats or hairbrushes). A louse cannot jump or
What are the symptoms?
The most common symptom of
lice is itching. There are different symptoms, depending on which type of lice
- Head lice may not cause any symptoms at
first. Itching on the scalp may start weeks or even months after lice have
started to spread. Scratching can make the skin raw. The raw skin may ooze
clear fluid or crust over, and it may get infected.
- Pubic lice
cause severe itching. Their bites may cause small marks that look like bruises
on the torso, thighs, or upper arms. If pubic lice get on the eyelashes, the
edges of the eyelids may be crusted. You may see lice and their eggs at the
base of the eyelashes.
- Body lice cause very bad itching, especially
at night. Itchy sores appear in the armpits and on the waist, torso, and other
areas where the seams of clothes press against the skin. The lice and eggs may
be found in the seams of the person's clothing but are generally not seen on
Frequent scratching can cause a skin infection. In the
most severe cases of head lice, hair may fall out, and the skin may get darker
in the areas infested with lice.
How is a lice infestation diagnosed?
A doctor can
usually tell if you have lice by looking closely for live lice or eggs in your
hair. The doctor may also comb through your hair with a fine-toothed comb to help detect lice. He or she may look at the lice or eggs under a microscope.
Your doctor can also find pubic lice and body lice by
looking closely at your body or your clothing.
How is it treated?