Pubic Lice (Crabs)

Pubic lice are diagnosed and treated by Premier Medical Group.

What are pubic lice?

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Pubic lice, known colloquially as “crabs,” are small but visible parasitic insects found in the pubic or genital area. Their presence is often indicated by general itching and visible nits or lice. Pubic lice are usually spread through sexual contact or by contact with certain articles, such as clothing, bed linens, or towels that have been used by somebody else with pubic lice.

As with all lice, pubic lice have three forms: the egg, or nit, the nymph, and the adult. Eggs, which are oval and yellow or white, are very difficult to see and are firmly attached to the hair shaft. Nymphs hatch from these eggs and become adults in two to three weeks, feeding on blood. Once the louse is matured, it will resemble a miniature crab when viewed through a small magnifying glass, though it will have only six legs. Treating pubic lice is simple but can take up to 2 weeks.

What causes pubic lice?

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Pubic lice are most often spread through skin-to-skin contact with an individual who is infected. This can, and often does, include sex, but it is not necessary for pubic lice to spread. Crabs can also end up in other types of coarse hair, such as eyelashes, eyebrows, chest hair, armpit hair, or facial hair.

Lice can also spread through shared clothing, bed sheets, and towels, but this is less common. Lice will only live for up to 48 hours when not attached to a host.

What are the symptoms of pubic lice?

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Symptoms of pubic lice often start around 5 days after contracting them. The most common symptom is an intense itching in the pubic area, which is caused by the body’s reaction to the lice bites. There may also be dark or blue spots on the skin where lice are living. In most cases, both eggs and adult lice may be visible toward the bottom of the pubic hair. Adult lice will get darker as they consume more blood, so they can appear to be tan, white, or brownish red.

Pubic lice may also cause a person to feel feverish, lethargic, or irritable, though this is a byproduct of a lice infestation. Scratching bites can cause sores, which can become infected with bacteria. This can cause fever symptoms.

How are pubic lice diagnosed?

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Diagnosing pubic lice is an easy process. Individuals can often see the small crabs in the genital area. A magnifying glass can help, or a doctor or nurse can look for them using a microscope.

Pubic lice may still be present even without a confirmed sighting. If an individual is experiencing extreme genital itching but cannot determine the source, it is important to see a nurse or doctor. If you can identify a recent sexual partner who might have transmitted pubic lice, it may also be a good idea to check with them.

Crabs are not dangerous, and they are very easily cured with over-the-counter treatments. However, it is important to secure a diagnosis as soon as symptoms appear. Pubic lice can spread easily and ridding yourself of the infestation is essential.

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Over-the-counter lotions and anti-lice shampoos are among the most popular treatments for pubic lice. This location will often contain 1% permethrin and/or piperonyl butoxide. You will not need a prescription to buy this at a pharmacy, and the medications are safe and effective when used exactly according to the instructions on the package or label. These treatments can last from one to two weeks, depending on the severity of the pubic lice. Additionally, topical ivermectin has been used successfully to treat lice.

Though the shampoo will kill nymphs and adult lice, nits, or eggs, may remain on the hair shaft. In addition to a shampoo, it is important to thoroughly search the pubic hair to remove nits. This can be done with fingernails, tweezers, or a fine-toothed comb. If you are conducting the inspection yourself, a magnifying glass, a mirror, and a bright light will make the process significantly easier.

Moreover, those with pubic lice will want to kill any lice or nits remaining on clothing, towels, or bedding. Machine-wash and machine-dry these items using hot water (at least 130 degrees Fahrenheit) and the hottest dryer setting. Items that cannot be laundered can be dry cleaned or stored in a sealed plastic bag for 2 weeks, at which point the lice will have died naturally.

When to see a doctor for pubic lice?

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In most cases, a doctor will prescribe an over-the-counter treatment for pubic lice. You should be able to secure this treatment without a clinical visit. However, if you are unsure of your diagnosis, or have not been able to identify the source of genital itching, it is a good idea to see a doctor. While pubic lice are a common source of genital discomfort, several other STDs may be to blame. A doctor can provide a definitive diagnosis through a range of tests, including microscopic evaluation, urine tests, and blood tests.

If you think you might have a different STD, check out our main resource page about sexually transmitted diseases.