Crabs (pubic pediculosis) is an infestation of the pubic hair with the lice (parasitic insect) Phthirus pubis, which lives by sucking blood from the soft pubic skin. Caught by being in close bodily contact with someone who already has an infestation (eg. during sex), but as the lice can survive away from humans for a time, they can also be caught from borrowed clothing, towels or bedding.
Often there are no symptoms and many people are unaware of the presence of lice. In others the lice cause an itchy rash in the pubic area, which may be raw and bleeding from constant scratching. Secondary skin infections may develop in these sores, and this infection can cause further symptoms including a fever and enlarged glands in the groin. Lice may be seen by examining the pubic hair through a magnifying glass.
A number of lotions are available to kill the crabs. The affected individual, and all sex partners, must be treated simultaneously to prevent reinfestations occurring. All clothing and bedding must be thoroughly washed in hot water. A repeat treatment after 24 hours and again after seven days is advisable in order to kill any lice that have hatched in the interim. Antibiotics may be required to treat secondary infections.
Correct treatment should result in a complete cure.