Pubic lice (termed medically as Phthirus pubis) are tiny yellow-grey parasitic insects about 2mm long that live in coarse body hair, such as pubic hair. They have a crab-like appearance hence the slang term ‘crabs’. Pubic lice are spread between people during close body contact, mostly via sexual contact.
Pubic lice lay eggs called nits and they appear as brownish dots attached to pubic hair. Pubic lice are not the same as the lice people get on their scalp.
- Itching affected area
- Black powder in underwear
- Small spots of blood on the skin caused by lice bites
- Inflammation caused by scratching
- Blue spots on the skin where the lice live (caused by lice bites)
Pubic lice are caught through close bodily (usually sexual) contact with someone who is infected. The lice cannot jump but instead crawl from the hair of one person to the hair of the other.
Unfortunately, condoms and other methods of contraception will not protect you from contracting pubic lice.
It’s also possible to get pubic lice from infected clothing, towels or bedding, although contamination in this way is quite rare.
If you think you are infected then go either to a sexual health clinic (also called a genitourinary medicine clinic or GUM clinic), or visit your GP or practice nurse. The health professional will usually be able to tell if you have pubic lice by examining the affected area.
Pubic lice live between one and three months. During their lifespan the female louse can lay up to 300 eggs. To survive the lice feed on human blood. They can only live for 24 hours when not on a human body. So they rarely leave the body they are on other than to move onto another person.
To treat them you’ll need to use an insecticide cream, lotion or shampoo. This normally needs to be applied once and repeated between three to seven days later. You’ll probably be advised to wash your whole body with the lotion, plus any facial hair.
You should also inform any recent sexual partners so that they can be treated at the same time, plus all other members of your household.
Insecticide creams are available on prescription or can be bought over the counter from your pharmacy. Before use, speak to your doctor or pharmacist to ensure you are using the treatment correctly.