Pubic lice, also known as crabs, are very small insects that infest your genital area. There are three types of lice that infest humans:
- pediculus humanus capitis (head louse)
- pediculus humanus corporis (body louse)
- phthirus pubis (pubic louse)
Pubic lice are distinct from body and head lice, and are often smaller in size. Lice feed on human blood and cause intense itching in affected areas. Pubic lice usually live on pubic hair and are spread through sexual contact. In rare cases, they can be found in eyelashes, armpit, and facial hair.
Pubic lice are transmitted through intimate contact, usually sex. However, it’s possible to catch pubic lice from using the blankets, towels, sheets, or clothing of people contaminated with pubic lice.
The adult louse lays its eggs on the hair shaft, near the skin. These eggs are called nits. Seven to 10 days later, the nit hatches into a nymph. Then it starts feeding on your blood. The lice can live without feeding on blood for a day or two.
Contrary to common belief, you’re highly unlikely to catch them from a toilet seat or furniture, as pubic lice don’t usually fall off their host unless they’re dead. They aren’t carried by animals and cannot jump from one person to another like fleas.
If a parent is badly infested, a child sleeping in the same bed might catch pubic lice. In children, the lice usually dwell in their eyelashes or eyebrows. The presence of pubic lice in a child might also indicate sexual abuse.
Pubic lice infestations are more common in people who have sexually transmitted infections (Mayo, 2010).
While some people have no symptoms, it’s more likely that your genitals and/or anus will start itching about five days after the initial infestation. At night, the itching becomes more intense. Other common symptoms include:
- low-grade fever
- lack of energy
- pale bluish spots near bites
Excessive itching may cause wounds or infection in affected areas. Children with lice infestations on their eyelashes are also at risk of developing conjunctivitis (pink eye).
Diagnosis is done through a visual examination of the pubic area. People are often able to diagnose themselves. If you suspect an infestation and you can’t see well enough to be sure, use a magnifying glass to look for small, crab-shaped insects.
Lice are pale gray in color, but darken after drinking your blood. If you see something moving, you probably are infested.
Pubic lice eggs are another indicator of infestation. The eggs are tiny, white, and found around the roots of your pubic or other body hair.
If you suspect an infestation but can’t be sure, visit your doctor or health clinic for diagnosis.
Treatment consists of decontaminating yourself, your clothes, and your bedding. Removing pubic lice from your body usually involves topical, over-the-counter solutions, such as RID, Nix, or A-200. In stubborn cases, prescription medication might also be necessary.
Depending on the extent of your infestation, you might only need to wash your pubic hair. Read the instructions to find out exactly how long to leave a particular product on your skin.
Even after successful treatment, a few stubborn eggs might cling to your hairs. Remove any leftover nits with tweezers. According to Planned Parenthood, home remedies like shaving and hot baths don’t work. Lice can easily survive ordinary soap and water (Planned Parenthood).
If you are pregnant or breastfeeding, or are treating an infant for pubic lice, ask your doctor which products are safe for you to use. If several people in your household have contracted pubic lice, treat everybody at the same time. This helps prevent reinfection.
Vacuum the entire house and clean the bathroom with bleach solution. Wash all towels, bedding and clothing in hot water and machine dry using the highest setting for at least 20 minutes. If you can’t wash or dry-clean something, seal it in an airtight plastic sack for 72 hours to kill any lingering lice.
If the lice survive these efforts, you might need stronger medicine, such as:
- malathion (Ovide): a topical lotion that you leave on the affected areas for eight to 12 hours
- ivermectin (Stromectol): a two-pill dose taken orally. You might need a follow-up dose 10 days later.
- lindane: the strongest and most toxic of commonly prescribed pubic lice medicines. You only leave it on for four minutes before washing it off. Don’t use this on infants or on yourself if you’re breastfeeding or pregnant.
For pubic lice in eyelashes, apply petroleum jelly to the lashes and eyelids three times a day for a few days. Alternatively, you can pluck the nits and lice with tweezers. Your doctor might prescribe a special lice medicine suitable for the eye area. Do not use regular lice shampoos around the eyes.
Itching may persist for a week or two as your body works through its allergic reaction to the bites. Call your doctor if you notice swelling, skin discoloration, drainage from wounds, or if you get the medication in your eyes.
To prevent infestation, avoid sharing clothes, bedding, or towels with anyone who has public lice. Sexual contact should be avoided until treatment is complete and successful.
Once you’ve been diagnosed with pubic lice, you must inform all sex partners so that they can be treated as well.