Crab Lice

Overview

Definition

Crabs, also called pubic lice, are tiny blood sucking parasites. They are usually found in the pubic hair. They can also be found in other body areas with short hair, such as the eyelashes, eyebrows, armpit hair, and mustache hair.

Pubic lice are often called crabs because they look like tiny crabs.

Pubic Louse
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Causes

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 are:

  • Sex with someone who has crab lice
  • Contact with unclean items, such as:
    • Bedding
    • Towels
    • Clothing

SymptomsandDiagnosis

Symptoms

Problems may be:

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

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done. Your doctor will be able to diagnose crab lice by viewing lice and lice eggs.

Treatments

Treatment

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

Prevention

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.

a (Pubic Lice; Pediculosis Pubis)

RESOURCES

American Academy of Dermatology https://www.aad.org 

American Congress of Obstetrics and Gynecology http://www.acog.org 

CANADIAN RESOURCES

Health Canada https://www.canada.ca 

HealthLink BC http://www.healthlinkbc.ca 

References

Lindane shampoo and lindane lotion. Food and Drug Administration website. Available at: http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm110452.htm. Accessed October 16, 2020.

Medication guide lindane shampoo. Food and Drug Administration website. Available at: http://www.accessdata.fda.gov/drugsatfda%5Fdocs/label/2003/006309shampoolbl.pdf. Accessed October 16, 2020.

Parasites—lice. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/parasites/lice. Accessed October 16, 2020.

Pediculosis pubis. EBSCO DynaMed Plus website. https://www.dynamed.com/condition/pediculosis-pubis-and-pediculosis-corporis. Accessed October 16, 2020.

Workowski KA, Bolan GA, Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2015. MMWR Recomm Rep. 2015 Jun 5;64(RR-03):1-137.