Crab Lice



Crab lice are parasites. They are insects that need to live off of a host. Crab lice are spread by contact with a person, usually during sex. Less often, crab lice may also spread by sharing items like bedding, towels, and clothing.

Risk Factors

Things that may raise the risk of crab lice are:

  • Sex with someone who has crab lice
  • Contact with items that have crab lice on them, such as:
    • Bedding
    • Towels
    • Clothing



Symptoms of crab lice may be:

  • Intense itching
  • Lice or eggs on body hair
  • Tiny blue bumps on the skin


The doctor will ask about symptoms and past health. A physical exam will be done. The doctor will diagnose crab lice by viewing lice and lice eggs.



Pubic lice can be treated with an over the counter shampoo or cream rinse. A prescription may be given if these medicines do not kill the lice.


Avoid close physical or sexual contact with anyone who has crab lice.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.