Pubic ("crab") lice are not known to transmit any disease. Itching ("pruritus") in the pubic and groin area is the most common symptom of pubic lice infestation. As with other lice infestations, intense itching leads to scratching which can cause sores and secondary bacterial infection of the skin.

Visible lice eggs ("nits") or lice crawling or attached to pubic hair, or less commonly other hairy areas of the body (eyelashes, eyebrows, beard, mustache, armpits, chest, back) are other signs of pubic lice infestation.

Pubic lice on the head (eyelashes or eyebrows) of a child may be an indication of sexual exposure or abuse.

Persons infested with pubic lice should be evaluated for other sexually transmitted diseases (STDs).