Pubic lice (Pthirus pubis), also called crab lice or crabs, are a parasitic infection of humans that is generally transmitted through sexual contact but may also be passed along by exposure to contaminated clothing, linens, or towels that have been used by an infected person. They do not actually transmit disease but create an itch sensation that may lead to a secondary bacterial infection through the breaks in the skin that were created by scratching.
Pubic lice are similar to head lice, but the pubic variety is much shorter in length. The life cycles of the two species are the same, and they both require human blood to survive. They will usually die within two days if they are unable to feed. Female lice will lay around 30 eggs during their lifespan, which lasts for around one month. When the eggs hatch after one week, they become nymphs, which then molt three different times before reaching adulthood. The eggs are attached to the shaft of hair for the week that they incubate.
Grooming and Shaving Reduces Risk for Pubic Lice
Men and women have begun to shave the hair from more of their body parts, and over the last several decades, fashion and hygiene have led more and more people to reduce or even completely remove their pubic hair. One study found that 74% of men and women groomed, with 66% of men and 84% of women grooming their pubic hair. The study defined extreme grooming as removal of all pubic hair more than eleven times per year and high-frequency grooming as trimming daily or weekly. They suggest that, as a result, pubic lice are more common in those who are low-frequency groomers (those who trimmed their pubic hair less than every week).
Similar to any species who does not have access to vital resources, pubic lice are unable to procreate when they have no hair on which they need to attach their eggs. It has been suggested that the removal of pubic hair in certain areas has led to dramatically reduced rates of infection. A research study demonstrated that there is a significant and strong correlation between high rates of pubic hair removal and reduced incidence of pubic lice infections, and they believe that the increased frequency of pubic hair removal may lead to the complete eradication of pubic lice infestation.
Treatment of Pubic Lice
The typical treatment for pubic lice is an over the counter topical lotion or mousse containing permethrin or pyrethrin/piperonyl butoxide. They are generally considered safe but are best avoided by patients who have known skin sensitivity. There have been reports of resistance to some of these topical treatments, so hair removal may even act as a simple and cheap form of treatment that has almost no side effects.
Condoms Do Not Protect Against Public Lice
Although condoms can help prevent the transmission of most forms of sexually transmitted infections, pubic lice cannot be prevented with condoms. Because this is a contagious infection, it is important that it is treated appropriately. If possible, all exposed partners must be found and properly treated so the infection does not potentially spread through a community.