What are pubic lice?

Also known as crotch crickets, love bugs and snatch monsters, pubic lice (Phthirus pubis) are tiny tan/grey parasites that thrive in pubic hair and live off human blood. 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 are 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.

Pubic lice can be traced back as far as biblical times, as they were often referred to in the Bible as the third plague, although some scientists have argued that they evolved from a common ancestor found on gorillas almost four million years ago. How humans picked up public lice from gorillas remains a mystery. The scientists, however, have ruled out bestiality and believe it is because of humans consuming infested gorillas or sleeping in their nests.

More recently, pubic lice were passed around during the 'free love' movement of the late 1960s and infection rates are even higher today.

What are the symptoms of pubic lice?

Although it's possible to be infested and not experience any symptoms, the most common indication is itching - especially at night. This can range from a mild irritation to something you want to take a cheese grater to. 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, so by then, you'll know if you've caught a dose. Under a microscope they look like a miniature 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.

How are the lice treated?

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 (GP), and they will easily spot any infestation - even during the first stage. If it is diagnosed early enough, the eggs can be removed with a nit comb, but once the lice have hatched, you'll need to buy a lice shampoo over the counter (pediculicide), or by prescription (Lindane). 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 if I ignore them?

Pubic lice are hard to ignore. If the itching doesn't get to you, the embarrassment will. The symptoms 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 discolored.

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 can I protect myself from contracting lice?

Because the lice live on pubic hair, condoms offer no protection. In fact, no change in sexual behaviour will protect you. Even abstinence may not be enough as you can still pick up by lice by sharing towels, bedding and clothing of an infested partner.

How soon can I have sex again?

If you want to keep your girlfriend/boyfriend, don't have sex until you've got rid of every generation of the nasty little critters. If you are still unsure, your GP or a nurse will tell you if you are in the clear.

Updated: 14/06/2011