Pubic Lice Or Crab Lice

What Is It?

Published: May, 2017

Pubic lice or crab lice are tiny insects that infest a person's pubic hair, although they also can be found on facial hair, armpit hair and eyelashes. The insects look like crabs, and a person with these lice often is said to have "crabs." Their claws let them grasp hairs so they can both move around and remain on their human host. Crab lice, like all lice, feed only on their host's blood. Female lice produce eggs, which are cemented to the hair shaft close to the skin. It takes about 7 to 10 days for an egg to hatch. Most people who are infested with crab lice will have about a dozen or fewer active lice on them at any one time, and the hairs may bear many live and hatched eggs.


Crab lice usually cause intense itching, due mainly to an allergic reaction to the saliva of the louse. There also may be tiny red or blue marks where the insect has been biting, and the eggs, or nits, may be seen attached to the pubic hair close to the skin. Sometimes, more severe reactions occur, such as the development of pustules or intense skin reactions where the insects have been feeding. Scratching the area may cause skin infection. Crab lice, themselves, do not transmit infections.

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