Pubic lice, also known as crabs, are tiny insects (about 2mm long) that live on coarse human body hair, such as pubic hair.
Pubic lice are not linked to poor personal hygiene.
How do you get pubic lice?
It can take up to 3 weeks after coming into contact with pubic lice before you notice any symptoms.
They are spread through close body contact with someone who has them, most commonly sexual contact.
The lice crawl from hair to hair but can’t fly or jump. They need human blood to survive, so generally only leave the body to move from one person to another.
Pubic lice don’t live on other animals such as cats or dogs.
It’s also possible for pubic lice to be spread through sharing clothes, towels and bedding.
Symptoms of pubic lice
The most common symptom of pubic lice is itchy red spots. The itching is caused by an allergy to the louse saliva or poo.
It can take 1 to 3 weeks for itching to develop after the first infestation, and it’ll usually be worse at night.
Adult pubic lice are tiny – smaller than a match head. They’re grey-brown in colour and have 6 legs. The 2 pairs of back legs are much larger and look like the pincer claws of a crab. They use these to grasp onto your hair.
Pubic lice eggs are tiny, yellow-white ovals, which are stuck firmly to the base of your hairs.
You may also notice the following symptoms:
- dark brown or black powder on your skin or in your underwear (this is louse droppings)
- blue spots on your skin where the lice have been, particularly on your thighs and lower stomach, caused by bites from the lice
- specks of blood in your underwear, if you have been scratching a lot
- nits (empty eggshells) that look like white oval dots attached to the base of your hairs
Testing for pubic lice
If you think you have pubic lice, make an appointment with your GP or local sexual health services.
There is no test for lice, but you may see the lice crawling in your body hair. Your GP or sexual health clinic will look for visible evidence of the lice.
Some sexual health clinics can find the lice and look at them under a microscope.
You can also buy treatment over the counter at your local pharmacist although they will not be able to diagnose the infestation.
Online appointment booking
You may be able to book an appointment for an STI test online using the online booking system. This varies for different NHS board areas.
Treatment for pubic lice
Pubic lice can be treated at home with (insecticidal) lotion or cream that will kill the lice. This will usually need to be applied once and repeated after 7 days.
Everyone that you’ve had close body contact with should be treated at the same time. This includes current sexual partners and may include members of your household.
Some pubic lice can be resistant to treatment. Resistance means that the lice will not be affected by a particular treatment. If your symptoms don’t settle, you may need to try more than one type of treatment. Your GP or sexual health clinic can advise you of suitable alternatives if your initial treatment doesn’t appear to have worked.
Pubic lice can also live on the eyelashes or eyebrows. This is because the thickness of these hairs is similar to pubic hair meaning that the lice can successfully grip on. Treatment of lice in the eye area is usually different to elsewhere as certain insecticidal creams or lotions are not safe for use near the eye area. Lice here can be removed with tweezers or Vaseline can be used to suffocate the lice prior to removal.
Avoiding passing on pubic lice to partners
If you or your partner has pubic lice, avoid having sex (vaginal, anal or oral) or close bodily contact until you both have finished the course of treatment, including any follow-up treatment.
This is to avoid re-infection or passing the infection on to someone else.
Reducing the risk of pubic lice
Pubic lice are easily spread, and condoms don’t protect against them.
The only thing that can reduce your risk of getting pubic lice is limiting the number of people with whom you have intimate or sexual contact.
If you have pubic lice it’s recommended you are tested for other STIs including: