Crabs STI guide

What are crabs? And how do you get rid of them?

We realise the thought of having lice crawling all over your pubes is the grossest thing ever, but luckily they’re easily zapped and, if treated early, harmless. Read our guide to the crabs STI to learn more.

What are crabs?

Officially called pubic lice, crabs are tiny tan/grey parasites that thrive in coarse pubic hair and live off human blood.

How do you catch crabs?

Unlike head lice, pubic lice don’t jump, but crawl from one person to another through skin-to-skin contact during sex. If you’re unlucky, you can also contract them if you share bedding, towels or clothing with an infested person.

Unlike most STIs, they’re not a virus or bacteria – they’re living creatures that start life as a nit (egg) that attaches itself to the hair shaft. It only takes about two weeks for a nit to hatch and mature into an adult louse, which means it doesn’t take long for the next generation to appear.

Crabs STI symptoms

Although it’s possible to be infested and not experience any symptoms, the most common symptom of public lice is itching – especially at night. This can range from a mild irritation to intense itching that can make you want to rip your bits off. It’s caused by the movement of the lice across your body and through your hair, and the body’s reaction to the proteins in their saliva.

What do pubic lice look like?

They begin life as white/yellow eggs about the size of a pinhead, but you may not be aware of their existence. A mature adult louse is about 2mm long, so by then you’ll know if you’ve caught a dose. Under a magnifying glass they resemble an actual crab, with a broad grey- or tan-coloured body, antennae and six legs. The first two legs are equipped with pincer claws, for hanging onto hair as they feed. Their droppings can also be seen as black dust on underwear.

Treatment for crabs

Although undesirable, a dose of pubic lice can be treated easily and quickly. Just go to your nearest genitourinary medicine (GUM) clinic or make an appointment to see your doctor. If it’s diagnosed early enough, the eggs can be removed with a nit comb, but once the lice have hatched you’ll need to use a lice shampoo, which is available by prescription or can be bought over the counter. Treatment may need to be repeated over seven to 10 days.

It’s important to wash all bedding, towels and clothing at a very high temperature to kill the lice and their eggs. Any sexual partners from the last month should also get themselves checked.

What do crabs do to you if you ignore them?

Pubic lice are hard to ignore. If the itching doesn’t get to you the embarrassment will. The symptoms will not only get worse, the lice may also spread to other hairy parts of the body, such as your armpits, chest, and face. The constant scratching not only raises eyebrows, it can also lead to a secondary bacterial infection, causing the infested area to become inflamed and discoloured.

Thanks to their prolific breeding it’s easy to become re-infected and pass them on, so unless you’re happy to have several generations of lice taking up residence in your intimate parts it’s essential you get rid of them as soon as possible.

How to prevent catching crabs

Because crabs live on pubic hair, condoms offer no protection. The best protection is to communicate with sexual partners and try to find out whether they might have lice or other STIs condoms can’t prevent, like genital warts or genital herpes. It’s not easy, and they might lie, but it’s your only option.

How soon can I have sex again after catching pubic lice?

If you have sex before you’ve got rid of every generation of the little blighters you’ll pass them on. Your GP or a nurse will tell you if you’re in the clear.

More safe sex advice

• Check out our safe sex resources here.
• Are you Getting Some? Get Tested! Search for a sexual health clinic near you
• Brook provides free sexual health and wellbeing services for young people in the UK. Brook’s services include local clinics and online digital sex and relationships tool.
• Chat about STIs on our Discussion Boards.