Pubic Lice ("Crabs")

What are pubic lice?

Pubic lice are tiny, flat-bodied, wingless insects that live on the skin. They are also called crabs because they have "claws", which they use to hang on to hair. They are light brown and the size of a pinhead. Pubic lice feed on the blood of a humans, however, they can live up to 24 hours away from the person. Pubic lice infect hairy parts of the body, especially around the pubic area. They look like small scabs to the naked eye. Their eggs (called “nits”) can be seen on hair close to the skin as little white dots. The eggs hatch in six to eight days.

Am I at risk?

Anyone can get pubic lice. It is estimated that there are over 1 million cases each year. However, people with more sex partners have a greater risk of getting pubic lice.

How are pubic lice spread?

They are usually spread through sexual contact, but you can occasionally pick them up through close personal contact or by using the unwashed bed linen, clothes, or towels of an infected person.

What are the signs and symptoms of pubic lice?

If you have pubic lice, you may not have any symptoms. If you do get symptoms, they usually begin 5 days to several weeks after getting the lice. You may get lots of itching around the pubic hair or the genital area. The itching is because of an allergic reaction to the bites. If you scratch, you could get a skin infection.

How are pubic lice diagnosed?

Pubic lice are diagnosed by a careful examination of the infected area. Seeing your health care provider can help because pubic lice can be confused with other skin problems. Also you should be tested for other sexually transmitted diseases.

How are pubic lice treated?

There are several options for treatment that you can discuss with your health care provider. These include special creams, lotions, or shampoos that you can buy in a drug store, as well as prescription lice medicines. Things to know about treatment include:

• Treatments may need to be applied more than once. Make sure you follow the directions.
• You do not need to shave your hair to remove crabs.
• Even after you finish treatment, you could have itching for a while.
• If you scratch a lot, you may cause an infection to start.
• If you get an infection, you should see your health care provider.

How can I prevent spreading pubic lice?

If you have pubic lice:

• Avoid close body contact with others.
• You should get treatment right away to prevent spreading them to others.
• Make sure you wash your clothes and bed linens in hot water and dry them in a hot dryer. If you can’t wash them, either dry-clean them or place them in a sealed bag for 2 weeks.
• If you find out you have crabs, you need to tell your sex partner(s) or anyone you have had close contact with or has shared your bed linens, clothes, or towels. These people should be treated even if they don't have an itch or a rash.

How can I avoid getting pubic lice?

You have a much lower chance of getting pubic lice if you have only one sex partner. Condoms do not stop pubic lice, so make sure your sex partner does not have them. Also, try not to use other people's clothing or bedding. As soon as you think you have pubic lice, treat it right away.

Written by the CYWH Staff at Children's Hospital Boston

Updated: 10/1/2009

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