What Are Crabs (Pubic Lice)?

What Are Crabs (Pubic Lice)?

“Crabs” is the common term for lice found in the pubic hair of humans. Officially known as Pediculosis pubis or pubic lice, these tiny parasites are barely the size of a pinhead and rely entirely on a host organism to survive. While thousands of lice species exist, some have evolved to thrive on humans. Pubic lice, scientifically named Pthirus pubis, are visible to the naked eye in affected areas. They typically attach to pubic hair but can also appear in other regions with coarse hair, such as the beard, chest, and armpits.

Morphology and Life Cycle

Pubic lice have a distinctive rounded shape with three pairs of legs on either side of the body, which gives them their descriptive name. Compared to head and body lice, pubic lice have a shorter female lifespan of about three weeks and produce fewer eggs per day (approximately three). Eggs attach to the base of pubic hair shafts for six to eight days before hatching.

Case Study: A Torrid Tale of Pubic Pediculosis

A recent case published in The New England Journal of Medicine describes a 65-year-old man who visited a dermatology clinic complaining of an itchy pubic area. Despite no visible rash or lesions, dermatologists used a hand-held dermoscope to examine the area. They discovered a nit firmly attached to a pubic hair shaft and observed a crab-shaped parasite, Pthirus pubis, moving between hairs.

The patient’s condition, known as pubic pediculosis, is typically sexually transmitted but can also occur through contact with contaminated fomites such as clothing, bedding, and towels. This condition most commonly affects teenagers and young adults. In this case, the patient reported no recent sexual contact, and no other sexually transmitted infections were identified during screening.

Treatment involved oral ivermectin, and within two weeks, the itching subsided. While effective treatment resolved the physical symptoms, the psychological impact of such an experience can linger.

Conclusion

Understanding pubic lice, their lifecycle, and transmission methods is crucial for effective treatment and prevention. You can learn more about them in another post titled, "Three Things You Probably Didn't Know About Pubic Lice." For more information on head lice treatment options, prevention tips, and professional lice removal services, visit our website, LargerThanLice.com.