Crabs are also most commonly known as ‘pubic lice’. Crabs appear like small flakes in the area and there may well be bluish spots on the skin where the lice have been feeding. Crabs are six-legged, parasitic insects often found in the genital area of humans. There are three stages in the life of a pubic louse: The nit, the nymph and the adult. Nits are the eggs of pubic lice. They are very difficult to see and firmly attach themselves to the hair shaft. They are about the same size as a mark at the end of an arrow. They are oval-shaped and vary in colour from yellow to white. Nits usually take about one week to hatch. The nit then hatches into a baby louse which is called a nymph. It looks very similar to an adult pubic louse but is smaller in size. The nymph must feed on blood in order for it to live. Nymphs usually mature into adults about seven days after hatching. The adult pubic louse resembles a miniature crab when it is viewed through a strong magnifying glass. Pubic lice have six legs but they have two larger front legs which resemble the pincer claws of a crab, hence the nickname. Public lice are tan to greyish-white in colour. Just like nymphs, adult pubic lice need to feed on blood to live. If they fall off a human, then pubic lice usually die within one to two days. Females lay nits and are usually larger than males. Finding a nymph or an adult can sometimes prove difficult, as there are usually very few of them and they can move quickly away from light. Non-prescription treatments for crabs include a 1% permethrin or pyrethrin lice shampoo, or you can obtain a prescription medicine called lindane from your doctor.
