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Crabs (pubic lice)

How common are crabs?

Once the most common sexually transmitted infection, crabs are no longer so high profile. Changing modern grooming habits, together with the fact that most people treat themselves at home, means crabs have slunk out of the sexual health limelight.

Crabs are also called pubic lice.

What causes crabs?

Crabs are easy to pick up. The lice are small, crab-shaped insects that are the size of a pin-head when fully grown. They live on body hair and feed on blood (but they cannot pass on HIV or other STIs).

The lice are found:

  • in the hair around your balls, arse and cock
  • on underarm hair, hairy legs and chests
  • sometimes in eyebrows and hair on the face.

They aren’t found in hair on your head as it’s not warm enough there.

The lice can live away from the body for about 24 hours, so can survive on clothes, bedding and towels.

What are the symptoms of crabs?

You could have crabs and not notice them. But two to three weeks after infection the lice usually cause itching, especially at night, and sometimes cause a rash.

You can often see fully-grown lice on the hair, but probably not if you’ve just been infected.

How are crabs passed on?

Crabs are passed on by:

  • body contact during sex
  • using towels, bedding or clothes of someone with crabs (this isn’t common but it can happen).

So if someone has crabs, it doesn’t necessarily mean they got them by having sex with someone else.

How are crabs prevented?

There’s no way of stopping yourself getting crabs. But if you have them you can prevent them spreading by:

  • making sure people who’ve shared your bed, towels or clothes are also treated
  • washing your bedding, towels and clothes on a hot wash which kills the lice and their eggs
  • dry-cleaning leather clothing or sealing it in a plastic bag for two weeks.

No one’s immune to crabs. If you’ve had them before, you can get them again.

How are crabs treated?

Treating crabs is cheap and easy, and can be done at home using a lotion such as Quellada, Derbac, Prioderm and Lyclear. These can be bought from a chemist without a prescription or you can get lotions free at a sexual health clinic. You put the lotion over your whole body (but not on your head or face), leave it on for 24 hours and pick off any lice you see left on your body.

If the treatment doesn’t work, see your GP or clinic.

Shaving off pubic hair will not get rid of crabs.

Last review: 15/11/2018
Next review: 15/11/2021