Lice are tiny wingless insects that live in the hairy parts of the human body. They are less than 1/8 inch long (2 to 3 millimeters), or about the size of a sesame seed. Lice that live in the pubic hairs of the genital area are called pubic lice or crab lice.
Lice bite through the skin to suck blood. They attach their eggs, called nits, to hairs. The nits hatch after several days, making more lice.
Lice are not dangerous and don’t spread disease. However, their bites can cause itching and skin irritation.
Pubic lice can be passed from person to person through close body or sexual contact. The lice can live up to 3 days away from the body, so you can get lice from things like bed sheets, towels, and sleeping bags if someone infected with lice has used them recently.
The most common symptom is itching. The more lice you have, the more severe the itching. If there are only a few lice, you may have no symptoms.
Your skin may get red and irritated, especially if you are scratching your skin. You may have small, red, itchy bumps. Sometimes the areas that you have scratched can get infected.
You may see lice or nits in your pubic hair. The nits look like tiny white dots attached to a hair, similar to dandruff. Unlike dandruff, the nits cannot be brushed or flicked off. They must be pulled off the hair with a fine-tooth comb or your fingers.
Lice sometimes live in other hairy areas, such as the chest, belly, and underarms. They may be in beards, eyebrows, and eyelashes. Children of parents who have pubic lice may get lice in the eyebrows or eyelashes causing itching, burning, or redness. This may be a sign of sexual activity or abuse.
Your healthcare provider will ask about your symptoms and medical history and examine you.
Lice will not go away without proper treatment. Anti-lice products can be bought without a prescription and used to treat lice. Follow the directions on the package. Some products require a second treatment in 7 to 10 days, while others recommend repeating the treatment only if live lice are still found in the hair.
If a nonprescription product does not kill the lice, you may need a shampoo prescribed by your healthcare provider. Prescription shampoos contain medicines that may cause side effects. It’s usually better to try one of the nonprescription products first.
If you are pregnant or breast-feeding, check with your healthcare provider before you use any type of anti-lice product.
After treatment with anti-lice medicine, the nits (eggs) will still be on your hair. You must remove all of the nits. Use a fine-tooth comb, tweezers, or your fingers to remove the nits. If you don't remove all of the nits, it may be hard to tell if the treatment worked.
Don’t have sex until you and your partner have completed the treatment and the lice and nits are all gone. If you have pubic lice, which is a sexually transmitted disease, you should be tested for other sexually transmitted diseases.
You need to remove lice from your clothing, towels, and bedding. Machine wash all items that you used in the last 3 days before you started treatment. Use hot water to wash the items. After washing, use the hot setting on your dryer for at least 20 minutes. Anything that cannot be washed this way needs to be dry cleaned. Clothing or other things, like stuffed animals or pillows, that may have lice but cannot be washed or dry cleaned should be sealed in a plastic bag for 2 weeks to kill the nits. Pets don’t need to be treated.
Vacuuming the floor and the furniture used by anyone who had lice may help keep the lice from spreading. Since lice can spread easily, everyone in your home should be examined carefully. Anyone who has lice or nits should be treated right away to avoid spreading the lice to others.
Tell anyone who you had sex with in the last month that they may need to be treated for pubic lice.
The best way to prevent pubic lice is to avoid sexual contact or to have just one sexual partner who is not having sex with anyone else. Condoms are part of safe sex practices but are not good protection against crab lice because condoms don’t cover the hairy areas where the lice live. Also avoid any clothing or bedding that someone who might have lice has worn or used unless it has been properly washed.