The STI Files: Pubic Lice

Stat: There are about 3 million new cases of pubic lice treated in the United States each year.

What is it exactly? Pubic lice is also called "crabs." It's caused by very tiny insects that live in the pubic hair⁠ and feed on human blood. The scientific name for pubic lice is Pediculosis pubis. Pubic lice are not the same as body lice.

About how many people have it? There are about 3 million new cases of pubic lice treated in the United States each year. It's unknown how many people have it at any one time.

How is it spread? Pubic lice are often spread through sexual⁠ contact, though genital contact or sexual intercourse⁠ is not necessary for transmission. Sometimes pubic lice can be spread through contact with unwashed bed linens, towels, or clothes that were used by someone with pubic lice. Contrary to popular fears, it's pretty unlikely you'll get pubic lice from a toilet seat. Lice can't move around or hang out⁠ for long on smooth surfaces. Animals also do not get or spread pubic lice, and pubic lice (specifically) also don't spread to the scalp.

What are its symptoms? The primary symptom is itching in the pubic area. The itching is caused by an allergic reaction to the lice bites and usually starts within 5 days after infection⁠ . Some people also get blue spots where they were bitten.

Scratching can spread the lice to other body parts with coarse body hair, such as the legs, armpits, mustache, beard, eyebrows, and eyelashes.

How is it diagnosed? Self diagnosis is possible, but difficult. If you have unexplained itching, you can check in with your healthcare provider⁠ or go to a sexual health clinic. A healthcare provider will do a visual examination, and might use a magnifying glass to help see if there are lice or lice eggs. Sometimes diagnosis may need to be done through analyzing a skin scraping or biopsy.

Is it treatable? Yes. There are lotions and shampoos that kill pubic lice. You can get these with a prescription from a healthcare provider or over-the-counter at a drug store. If you're going the over-the-counter route, a pharmacist can advise you on which medication to use and how to use it.

Some of these medications should not be used by pregnant or breastfeeding people, nor by young children. Be sure to check with your healthcare provider or pharmacist if you have any questions.

You'll also need to clean⁠ everything that might have come into contact with the lice. You'll need to wash all dirty clothes, bed linens, and towels in very hot water. If something can't be washed, it needs to be put in a sealed plastic bag for 2 weeks to make sure the lice have died off.

You might still itch after treatment, because the skin takes time to heal from the bites. Something like calamine lotion may help keep you comfortable while you heal.

Is it curable? Yes, but you can get infected again. If you are infected, make sure all of your sexual partners are treated at the same time that you are treated.

Can it affect fertility⁠ ? There are no known effects of pubic lice on fertility.

Can it cause death? Pubic lice do not cause anything more than discomfort and inconvenience, though people who scratch the bites can get a secondary bacterial infection. This can be treated with antibiotics prescribed by your healthcare provider.

How can we protect against it? The vast majority of pubic lice cases occur from genital contact, so the best way to avoid pubic lice is to abstain from sexual or other kinds of genital contact. Unfortunately for people who do participate in genital contact, there are no known ways to protect from pubic lice.

Condoms do an ace⁠ job of lowering risk for getting or spreading other STIs, but they don't do a lot for preventing pubic lice because they don't cover the entire genital area.

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