Also known as pubic lice, or the crab, the crab lice are a parasite that infects the course hairs of the human body. Normally this means pubic hair, but they can also infect armpit hair, chest hair, eyelashes, and other coarse hair. Most countries don’t require incidences crab lice to be reported, so there is no reliable statistics on how common they are. The best available estimate is that they infect approximately 2% of people worldwide.
Prevention: Not having intimate contact with people who are infected is the best protection. As life can be transmitted through bedding, towels, and other fabrics this is not 100% protection, but it’s definitely your best bet. Several sources recommend practicing safer sex to prevent transmission. I can only assume that this is a default recommendation for all STD/STI’s, as the only barrier method which might provide some protection against lice is female condoms. Basically, unless you are wrapping the entire general area in a plastic bag and having no direct contact, crabs can be transmitted. I do not know of any commercially available protection which actually does cover the entire genital area. And that doesn’t even count the possibility of infection being transmitted from someone’s armpit hairs or sheets.
Treatment: Lice can be gotten rid of with an over-the-counter or prescription shampoo. Eggs are removed by combing with a fine toothed comb. In order to prevent possible reinfection, bedding and towels and any clothing which comes into contact with the infected area should be washed in hot water.
Symptoms: The main symptom of crab lice is a persistent itching in the pubic area, which is usually worse at night. Itching is caused by a reaction to the crab lice saliva. Sometimes, though not always, the skin around the bites will turn blue-gray. A careful examination will find eggs, small white dots, attached to the hair.
Diagnosis: Crab lice are one of the few STD/STIs that don’t require an official diagnosis. If you see the eggs on your pubic hair, you can go down to the drug store and get an over-the-counter treatment. If you do go to a doctor, they will diagnose based on the presence of eggs, itching and if necessary they will look at your hair under a microscope to see the crabs themselves.
Complications: The main complication of a lice infection is scratching yourself or on developing an infection in the scratches. The US National Health Institute recommends that anyone who has crabs be tested for other STD/STI’s, as apparently they are often transmitted together.
Overall, crab lice are more of an annoyance than a serious concern, but I still wouldn’t want to play host to them. For more on STD/STIs, check out the Long List of STD/STIs.