How Can You Get Crabs?

Getting pubic lice, often called crabs, happens through direct skin-to-skin contact with someone who has them. This usually means sexual contact, but it can also occur through sharing infested bedding, towels, or clothing. The lice do not jump or fly; they crawl from one person to another when bodies are close together.

What Exactly Are Pubic Lice and How Do They Spread?

Pubic lice are tiny insects that live in coarse body hair. They are a different species from head lice or body lice. The medical name is Pthirus pubis. These parasites feed on human blood and lay eggs, called nits, at the base of hair shafts.

The most common way people get crabs is through sexual activity. This includes vaginal, anal, or oral sex. The lice move from one person’s pubic hair to another’s during close body contact. Condoms do not prevent the spread of crabs because the lice live on hair outside the area a condom covers.

Non-sexual transmission is less common but possible. Sharing a bed with an infested person can transfer lice through sheets or blankets. The same goes for sharing towels or underwear. The lice can survive away from a human body for about 24 to 48 hours, which gives them a short window to find a new host.

How Can You Get Crabs Without Sexual Contact?

Yes, it is possible but much less likely. The CDC reports that pubic lice are usually spread through sexual contact, but they acknowledge non-sexual routes exist. You might get crabs from sleeping in the same bed as someone who has them, especially if you share the same sheets night after night.

Sharing infested clothing or towels is another route. If someone with crabs uses a towel and you use it right after, the lice might crawl onto you. The same risk applies to borrowing underwear or pants from an infested person. The lice prefer coarse hair, so they are most often found in the pubic area, but they can also live on armpit hair, chest hair, eyebrows, or eyelashes in rare cases.

Children getting crabs is unusual and raises concern. If a child has pubic lice, it is often from sharing a bed or towels with an infested adult. In rare cases, it can be a sign of sexual abuse, so doctors take this finding seriously and investigate further.

What Are the First Signs You Have Crabs?

The main symptom is itching in the pubic area. This itching is caused by an allergic reaction to the lice bites. It usually starts about five days after the lice attach to you. The itching gets worse at night when the lice are most active.

You might also see visible signs. Look for tiny gray or brown bugs moving in your pubic hair. They are about the size of a pinhead. You may also see small white or yellow eggs glued to the base of your hair shafts. These eggs are called nits and are hard to remove.

Other symptoms include small blue spots on the skin where the lice have bitten. These are called maculae caeruleae. You might also see dark specks in your underwear, which are lice droppings. Scratching can lead to secondary skin infections, so it is important to treat the infestation quickly.

How Is a Pubic Lice Infestation Diagnosed?

Diagnosis is straightforward. A doctor or nurse can identify pubic lice by looking at your pubic hair with a magnifying glass or using a special light called a Wood’s lamp. The lice and nits are visible to the naked eye if you know what to look for.

You can also check yourself at home. Use a bright light and a magnifying mirror. Part your pubic hair and look for the small bugs moving around. Check the base of the hairs for nits. They look like tiny sesame seeds glued to the hair shaft.

If you find lice or nits, you do not always need to see a doctor. Over-the-counter treatments work well. But see a doctor if the itching is severe, if you have open sores from scratching, or if you are pregnant or breastfeeding and need guidance on safe treatments.

What Treatments Actually Work for Crabs?

Over-the-counter lotions and shampoos containing permethrin or pyrethrin are the first-line treatments. Permethrin 1% is available as a cream rinse. You apply it to affected areas, leave it on for 10 minutes, then wash it off. One treatment usually works, but a second application after seven days is recommended to kill any newly hatched lice.

Prescription treatments are available for resistant cases. Malathion lotion 0.5% is a stronger option. It is applied for 8 to 12 hours then washed off. Ivermectin pills are another prescription option for people who cannot use topical treatments.

Treatment is not just about the medicine. You also need to remove the nits. Use a fine-toothed comb or your fingernails to pull the eggs off your hair shafts. This step is tedious but important because the medicine kills live lice but may not kill all the eggs.

Here is a comparison of common treatments:

What Should You Do After Treatment to Prevent Reinfestation?

After treating yourself, you must clean your environment. Wash all bedding, towels, and clothing in hot water. Use the hottest water setting your fabrics can handle. Dry them on high heat for at least 20 minutes. The heat kills both lice and eggs.

Items that cannot be washed can be dry-cleaned or sealed in a plastic bag for two weeks. Lice cannot survive that long without a host. Vacuum your mattress and furniture thoroughly. Do not use insecticide sprays on your bed or furniture; they are not needed and can be harmful.

Sexual partners from the past month should also be treated. Even if they have no symptoms, they might be carrying lice. Treating everyone at the same time prevents passing the lice back and forth. You should avoid sexual contact until all partners have completed treatment and have no signs of lice.

Do not use home remedies like mayonnaise, petroleum jelly, or tea tree oil. Research shows these are not reliably effective. Some people report success with them, but strong evidence is limited. Stick with the proven medications.

Common Misconceptions About How You Get Crabs

A major myth is that getting crabs means you are unclean. This is false. Pubic lice do not discriminate based on hygiene. Anyone who has close contact with an infested person can get them. Showering frequently does not prevent or cure an infestation.

Another misconception is that crabs can spread through toilet seats. This is not true. The lice need body heat and close contact to move. They cannot survive on cold, hard surfaces like toilet seats long enough to transfer to another person.

Some people believe pets can carry crabs. This is also false. Pubic lice are species-specific to humans. Your dog or cat cannot get them or spread them to you. If you have an infestation, the source is another human.

Finally, do not assume that over-the-counter treatments are enough if you have a severe infestation. Some people need prescription treatments, especially if they have tried OTC products correctly and the lice are still there. Resistance to permethrin has been reported in some regions.