Pubic lice, commonly called crabs, are treatable with over-the-counter medicated lotions or shampoos that kill the lice on contact. Most people can clear an infestation at home within one to two weeks using products available at any pharmacy, though a second application is usually needed to catch any newly hatched lice. Here’s what works, what doesn’t, and how to make sure they don’t come back.
Over-the-Counter Treatments
Two types of medicated products are the standard first-line treatment. One contains 1% permethrin as a cream rinse. The other is a mousse or shampoo combining pyrethrins with piperonyl butoxide. Both are applied to the affected area and washed off after 10 minutes. You can find either at most drugstores without a prescription.
Apply the product to all areas with coarse body hair where lice or eggs might be hiding, not just the pubic region. That can include the thighs, lower abdomen, chest, armpits, and even beards. Follow the product’s instructions closely, especially the timing. Washing it off too early reduces effectiveness, and leaving it on longer than directed won’t help and may irritate your skin.
A single treatment won’t always finish the job. Female lice lay around 30 eggs over their three- to four-week lifespan, and those eggs hatch in about a week. Because these products have limited ability to kill unhatched eggs, you should plan on a second treatment 7 to 10 days after the first. This catches any lice that hatched from surviving eggs before they’re old enough to lay new ones.
When OTC Products Don’t Work
Resistance to permethrin and pyrethrins has been increasing and is now widespread. If you’ve followed the instructions carefully, completed the second treatment, and still see live lice, you’re likely dealing with a resistant strain. At that point, a prescription option is the next step.
Malathion lotion (0.5%) is a prescription alternative. It’s applied to affected areas and washed off after 8 to 12 hours, a much longer contact time than the OTC options. It can kill some eggs in addition to adult lice, which gives it a slight edge in stubborn cases.
Oral ivermectin is another prescription option. It’s taken by mouth with food (eating increases how well your body absorbs it) and repeated in 7 to 14 days. Like the OTC treatments, it has limited ability to kill eggs, so that second dose matters. Your doctor can help decide which prescription route makes the most sense for your situation.
Shaving and Home Remedies Don’t Work
Shaving the affected area is one of the most common things people try first, and it doesn’t work. Lice and their eggs (called nits) attach firmly to hair shafts close to the skin, and a razor won’t reliably remove them all. Hot baths don’t kill them either. Cleveland Clinic is direct on this point: medicated lice-killing products are the only treatments that reliably eliminate an infestation.
Cleaning Your Environment
Pubic lice can survive for a short time on fabrics, so treating your body alone isn’t enough. Machine-wash and machine-dry all clothing, towels, and bedding you used in the two to three days before treatment. The water needs to be at least 130°F, and you should use the hot dryer cycle. This combination kills both lice and their eggs.
For items that can’t be washed, seal them in a plastic bag for 72 hours. Pubic lice can’t survive more than a day or two without a human host, so bagging items for a few days is enough to kill any stragglers. You don’t need to fumigate your home or use pesticide sprays on furniture.
Treating Partners
Crabs spread primarily through close body-to-body contact, especially sexual contact. Any sexual partners you’ve had recently should be notified and treated at the same time, even if they don’t have symptoms yet. If only one partner is treated, reinfection is almost guaranteed. Avoid sexual contact until both you and your partner have completed treatment and confirmed the lice are gone.
Because pubic lice share a transmission route with other sexually transmitted infections, getting screened for STIs after a diagnosis is a reasonable precaution.
Lice on Eyelashes or Eyebrows
Pubic lice occasionally spread to eyelashes or eyebrows. The standard medicated rinses cannot be used near the eyes. Instead, the treatment involves applying a thin layer of petroleum jelly (like Vaseline) to the lashes or brows with a cotton swab each night, then washing it off in the morning. The petroleum jelly smothers the lice. This process typically needs to be repeated nightly for several weeks. Be careful not to get it directly in your eyes.
How to Know the Treatment Worked
After completing both rounds of treatment, check the affected areas carefully. You’re looking for live, moving lice. Dead nits may remain attached to hair shafts for a while even after successful treatment, so the presence of eggs alone doesn’t mean you still have an active infestation. A fine-toothed nit comb can help remove leftover eggs.
If you still see live lice a week after your second treatment, the infestation hasn’t cleared and you’ll need to move to a prescription option. Itching can linger for a few days after lice are gone because of residual skin irritation, so persistent itching alone isn’t necessarily a sign of treatment failure.