Pubic Crabs and Sexual Transmission

Pubic lice (Pthirus pubis), commonly known as “crabs,” are tiny, blood-feeding parasites that sometimes live and lay their eggs in body hair, especially pubic hair. Infestations of pubic lice, or pediculosis pubis, are usually transmitted through sexual contact.

While pediculosis pubis is often a sexually transmitted infection (STI) (sometimes called a sexually transmitted disease, or STD), pubic lice can also spread through other forms of close contact, including sharing personal items such as towels.

This article goes over how people get crabs, as well as how to identify crab eggs and bites, prevention tips, and treatment options.

How People Get Crabs

Most of the time, pubic lice spread through sexual contact. They crawl, rather than flying or hopping, and don’t live long on their own, so they can usually only move from person to person through some form of intimacy.

Intimacy and Sex

Usually, pubic lice are transmitted via sexual contact, especially any kind of sexual activity that involves genital-to-genital contact. That’s why pediculosis pubis, or crabs, is often referred to as an STI.

Most cases of crabs occur in adults. According to the Centers for Disease Control and Prevention (CDC), people who have pubic lice should also be tested for other STIs. If a child has pubic lice, it may be a sign of sexual abuse.

Non-Intimate Transmission

In rare cases, you can get crabs from nonsexual contact with someone else’s personal items. For example, some people get crabs from using or sleeping on infested towels, bedsheets, clothing, sleeping bags, razors, or blankets.

Despite common misconceptions, pubic lice aren’t transmitted through contact with pets, such as cats or dogs. They technically can be spread through toilet seats, but this is exceedingly rare.

Identifying Crab Eggs and Bites on Genitals

Crabs look distinctively different from other kinds of lice, such as body or head lice. The pubic louse gets its name from its crab-like appearance, with a round, short body and noticeable pincers, which resemble claws. They reach up to 1.8 millimeters (mm) in length as adults.

Pubic lice are almost always found in the hair on or around the vagina or penis. However, they can also be found in your:

• Armpit hair
• Chest hair
• Beard
• Mustache
• Perianal hair
• Eyebrows
• Eyelashes

Crabs typically don’t prefer living in the hair on your head, so they are unlikely to end up on your scalp.

Pubic lice go through the following three stages of development:

• Nits: Nits, or lice eggs, are yellow or white and oval-shaped. They are typically found at the root of a coarse hair. You may not be able to see them with the naked eye.
• Nymphs: Think of nymphs as juvenile or “adolescent” pubic lice. These small parasites feed on blood and hatch within about three weeks.
• Lice: In their final stage of growth, pubic lice are gray-white or beige, have six legs, and develop their characteristic pincers.

Sometimes, you can see pubic lice crawling in their pubic hair when the lice reach maturity. Usually, though, the primary sign that you have crabs is severe itching around your genitals. You may also notice signs of lice feces, which appear as red or brown spots in your underwear.

Lice bites on your skin may appear, which usually show up as tiny blue or red marks. If your eyelashes are affected, they may crust over or stick together.

What Waxing and Shaving Doesn’t Do for Crabs

There is some evidence that pubic lice are becoming less widespread across the world due to the growing popularity of pubic hair removal methods, such as waxing and shaving, which remove the natural habitat of crabs.

However, simply waxing or shaving off your pubic hair is not an effective treatment method if you already have pubic lice. It’s also not a foolproof prevention method. Pubic lice can live on even small amounts of hair. Instead, it’s important to treat your lice with a medicated shampoo or topical lotion.

Medicated Shampoos for Crabs

Typical cleansers won’t get rid of crabs on their own. Instead, you’ll need to use over-the-counter (OTC) or prescription shampoos or topical treatments that contain specially formulated insecticide.

Lotions, cream rinses, and mousses that contain 1% permethrin as the active ingredient are typically the first-line treatment option. If this doesn’t work, your healthcare provider might recommend that you take Ovide, a lotion containing 0.5% malathion.

Shampoos that contain lindane are sometimes prescribed to kill pubic lice and is rarely recommended. However, lindane shampoo has severe potential neurological side effects. It is unsuitable for many groups of people, including those who are breastfeeding or pregnant, babies, children, and older adults.

To get rid of crabs, wash and dry your genital area or any other affected parts of your body. Then, use the medicated shampoo or lotion exactly as directed. You can pick off any visible nits with your hands or a comb. After treating the affected area, wear fresh clothes and change your bedding and towels.

You can also use OTC anti-itch creams, such as hydrocortisone, to relieve intense itching. However, it’s important to remember that relieving your symptoms won’t kill your pubic lice.

If you have lice or nits on your eyelashes and/or eyebrows, your healthcare provider may prescribe a 10-day course of ophthalmic-grade petrolatum ointment to be applied to the edges of your eyelids.

Crabs Treatment Timeline

After your first treatment for crabs, it could take over a week for all the pubic lice to be killed off. If you can still see lice, you should undergo a second treatment nine to 10 days after the first one.

During treatment, it’s best to avoid prolonged physical contact with others and share items like bedding and clothing. Your sexual partner(s) and anyone you regularly share personal items with should be informed, tested, and treated for crabs.

Cleaning Bedding, Towels, and Other Fabrics

If you have pubic lice, it’s crucial that you prevent reinfestation by thoroughly cleaning your bedding, towels, blankets, clothing, and any other fabrics that you used up to three days before your first treatment.

In a washing machine, clean your fabrics in hot water (130 degrees F or hotter) and dry them on a high-heat cycle. Another option is professional dry cleaning. Any clothing and other fabrics that you can’t dry clean or wash in hot water should be sealed in a plastic bag for at least two weeks.

It’s also a good idea to vacuum your mattress and rugs. Some people think you should have your home fumigated or call an exterminator, but that isn’t necessary when it comes to pubic lice.

How to Tell a Sexual Partner About Crabs

Talking to a sexual partner or potential sexual partner about having crabs or any other STI may seem daunting. However, it’s the right thing to do for your personal well-being, your partner’s safety, and your mutual intimacy. Here are a few tips:

• Plan ahead: Think about what you’ll say ahead of time, as well as how your partner might respond. You might also prepare resources or educational information ahead of time. This may help you feel a little less nervous about the conversation.
• Get comfortable: Make sure you have plenty of time and space to have a private conversation in a safe and comfortable place for both of you.
• Be open and honest: Be as straightforward as possible without missing crucial information. Be open to answering your partner’s questions and hearing out their concerns, as long as they are relevant and respectful.
• Discuss what to do next: Plan out the next steps together – such as one or both of you getting tested for STIs, setting up a meeting with a healthcare provider, or learning more about safe sex methods.

Summary

Pubic lice, also known as crabs, are blood-sucking parasitic insects that often get transmitted from person to person through sexual intercourse and other forms of sexual contact. They can also spread when people share infested clothing, bedding, and other fabrics.

The main symptom of crabs is genital itchiness. You may also know you have crabs if you see nits (lice eggs) or adult lice in your pubic hair.

If you think you may have crabs, talk to your healthcare provider about assessment and effective treatment options. Medicated shampoos and lotions can kill the pubic lice. After treatment, you should wash your clothes and other fabrics with hot water and dry them thoroughly.