What are crabs (pubic lice)?
Crabs, also known as pubic lice, are tiny parasitic insects that infest coarse human hair, most commonly in the pubic region. An estimated 3 million Americans get pubic lice each year, though cases have been declining in recent decades due to changing grooming habits. Like scabies, crabs are a parasitic infestation spread through close physical contact.
However, they can also be found in other areas with coarse hair, such as the armpits, chest, beard, eyebrows, and eyelashes. Pubic lice feed on human blood and lay eggs, or nits, that attach to hair shafts. While crabs are annoying and cause discomfort, they do not transmit diseases.
Symptoms & Causes
The primary symptom of a pubic lice infestation is intense itching in the affected area. This itching is caused by an allergic reaction to the bites of the lice. The itching may not start immediately and can take from three days to several weeks to develop after the initial infestation.
Pubic lice symptoms in adults
Signs and symptoms include:
- Intense itching in the pubic area
- Visible nits (lice eggs) attached to the base of pubic hair
- Small, crab-like lice visible on the hair shafts
- Red or blue bite marks or sores in the pubic region caused by scratching
- Irritation or inflammation of the skin in the infested areas
Pubic lice can also infest other hairy areas of the body, such as the armpits, chest, beard, and eyelashes, leading to similar symptoms in those areas.
How do you get crabs?
Crabs are primarily spread through close skin-to-skin contact, most commonly during sexual activity. They can also be transmitted by sharing personal items, such as clothing, bed sheets, and towels, that have come into contact with an infested person. While rare, pubic lice can also spread through the use of an infested toilet seat immediately after use by an infected person.
It’s important to note that pubic lice cannot be spread by animals, as they only infest humans.
Testing & Treatment
Testing for crabs
Diagnosing a pubic lice infestation is usually straightforward and involves visually identifying the lice or their eggs in the affected area. This can often be done by the individual or by a healthcare provider. No special tests are typically required, but a magnifying glass may be helpful in identifying the lice or nits.
If you suspect you have crabs, it is also recommended to get tested for other sexually transmitted infections (STIs), as pubic lice can co-occur with other infections.
Treatment for crabs
Pubic lice infestations are treated using over-the-counter or prescription medications specifically designed to kill lice. These treatments typically include lice-killing lotions or shampoos containing 1% permethrin or pyrethrins with piperonyl butoxide.
Steps for treatment include:
- Apply the medication according to the instructions on the package or as directed by your healthcare provider.
- Wash all clothing, bedding, and towels used by the infested person in hot water (at least 130°F/60°C) and dry on a high heat setting.
- Avoid close physical contact with others until treatment is complete.
- Repeat the treatment after seven days to ensure that any newly hatched lice are also killed.
It’s important not to attempt to remove the lice manually or to use fumigant sprays, as these are not effective and can be harmful.
Preventing crabs
To prevent the spread of pubic lice:
- Avoid sharing personal items such as clothing, bedding, or towels.
- Practice safe sex and consider examining yourself and your partner for signs of lice before engaging in sexual activity.
- If you or your partner has been diagnosed with pubic lice, both should undergo treatment to prevent reinfestation.
Regular sexual health check-ups can also help detect and manage pubic lice and other sexually transmitted infections.
Telling your partner
If you have crabs, you should tell your current partners and anyone else that you’ve had sex with in the last 6 months. They can have crabs without knowing it, so they should get tested as well.
TellYourPartner.com helps you send an anonymous crabs text, so you can let partners know they’ve had contact with an infection without revealing your name.