If you’ve heard the term “crabs” used in a medical context, it’s not referring to sea creatures. “Crabs” is the common nickname for pubic lice (Pthirus pubis). While the topic can be uncomfortable, pubic lice are a very common and treatable condition.
Here is everything you need to know about what they are, how they spread, and how to get rid of them.
1. What Exactly Are Pubic Lice?
Pubic lice are tiny, parasitic insects that infest the pelvic area. They are called “crabs” because, under a microscope, their rounded bodies and large front claws look very similar to miniature sea crabs.
These lice survive by feeding on human blood. While they are most commonly found in pubic hair, they can occasionally migrate to other areas with coarse body hair, such as:
- Armpits
- Chest hair
- Beards or mustaches
- Eyebrows or eyelashes (more common in children)
2. How Do You Get Crabs?
Contrary to popular belief, pubic lice do not jump or fly. They move by crawling.
- Sexual Contact: This is the most common way they are transmitted. Skin-to-skin contact during sexual activity allows the lice to crawl from one person to another.
- Physical Contact: Non-sexual close contact (like hugging) can occasionally spread them.
- Shared Items: It is possible—though less common—to catch crabs from sharing infested clothing, towels, or bed linens.
- Note: You cannot catch pubic lice from a toilet seat, as the lice cannot live long away from the warmth of a human body and their claws cannot grip smooth surfaces like plastic.
3. What Are the Symptoms?
The most common symptom of pubic lice is intense itching in the genital area. This usually starts about five days after the initial infestation.
Other signs include:
- Visible Lice: You may see small, tan, or grayish-white insects crawling in the hair.
- Nits (Eggs): Tiny white oval specks attached firmly to the hair shafts.
- Dark Spots: Small spots on your skin or underwear that are actually louse feces.
- Blue Spots: Small, pale blue bruises on the skin where the lice have been feeding.
- Irritation: Redness or inflammation caused by scratching.
4. Diagnosis and Treatment
The good news is that “crabs” are easily treatable.
Diagnosis
You can often diagnose pubic lice yourself by using a magnifying glass to look for lice or eggs. However, seeing a doctor is recommended to confirm the diagnosis and to screen for other STIs.
Treatment Steps
- OTC Lotions: Most cases can be treated with over-the-counter shampoos or lotions containing permethrin or pyrethrins. Follow the package instructions exactly.
- Prescription Medication: If OTC treatments don’t work, a doctor may prescribe stronger lotions (like Malathion) or oral medications (like Ivermectin).
- Clean Your Environment: Wash all clothes, bedding, and towels used in the last 48 hours in hot water (at least 130°F or 54°C) and dry them on high heat.
- Inform Partners: Notify any sexual partners from the last month so they can be checked and treated simultaneously to prevent “ping-pong” reinfection.
5. Prevention
- Limit Partners: Reducing the number of sexual partners can lower your risk.
- Avoid Sharing Personal Items: Don’t share towels or clothing with someone who has an active infestation.
- Check Regularly: If you experience unexplained itching, seek a medical evaluation immediately.
Important Note: Condoms are highly effective at preventing many STDs (like HIV or Chlamydia), but they do not fully protect against crabs because the lice live in the hair surrounding the genitals, not just the areas covered by a condom.
Summary
While “crabs” can be itchy and embarrassing, they are not dangerous and do not spread diseases. With the right medicated shampoo and a thorough cleaning of your environment, you can clear the infestation quickly and get back to your normal life.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional for diagnosis and treatment.