Pubic lice (Crabs)

Pubic lice (Crabs)

1. Pubic lice are tiny parasitic insects that live in coarse body hair, such as pubic hair. They are yellow-grey and about 2mm long. They have a crab-like appearance so they are often known as crabs. The eggs appear as brownish dots fixed to coarse body hair. Pubic lice are different from the head lice which some people get on their scalp.

2. Parasitic lice belong to the insect order Phthiraptera and include two main groups. The group that includes the human lice is known collectively as "Anoplura", or the sucking lice. There are over 550 species in the world, all of which are blood-sucking parasites of mammals, including wildlife, livestock, and pets.

3. The second group contains the chewing lice, known collectively as "Mallophaga". This is a large and diverse assemblage of over 2,650 species in the world, none of which suck blood. Instead, they possess weak chewing mouth parts and feed on feathers, fur, and skin debris on their host.

4. Crab lice are very small (1.5-2 mm; 0.06-0.08 inch),wingless, flattened insects with mouth parts for sucking blood. Crab lice have a large claw at the end of the last two pairs of legs that fits snugly around a hair shaft, allowing them to cling securely to coarse hair on their host. The claws resemble those of an aquatic crab, hence the common name of 'crab lice'.

5. In all stages of their life cycle, crab lice feed frequently on human blood. The adult female lays about four eggs (nits) per day. These are glued to hairs. The young emerge 7-10 days later, after being incubated by body heat, and must feed on blood within about 24 hours in order to survive.

6. You can get pubic lice by having close body contact-such as sex with someone who already has them. It is also possible to get them by sharing towels, clothes or someone's bed. Condoms do not prevent the transmission of pubic lice.

7. Symptoms include itching in the genital area and visible nits (lice eggs) or crawling lice.

8. Tiny, brick-red specks (faeces) usually on underwear or sheets, but sometimes on skin as well. 

9. Tiny white, oval, shiny attachments stuck near the base of pubic hairs; these are the eggs, and are not to be confused with hair follicles.

10. A pubic lice infestation is diagnosed by finding a "crab" louse or egg (nit) on the hair in the pubic region or, less commonly, elsewhere on the body (eyebrows, eyelashes, beard, moustache, armpit, perianal area, groin, trunk or scalp).

11. Pubic lice may be difficult to find because there may only be a few. Pubic lice often attach themselves to more than one hair and generally do not crawl as quickly as head or body lice. If crawling lice are not seen, finding nits in the pubic area strongly suggests that a person is infested and should be treated.

12. Without treatment, public lice can remain present as long as there are adult female lice that can feed on blood and lay nits which will develop into adult lice.

13. Pubic lice will not go away without treatment. Treatments for pubic lice include using a special lotion or shampoo to kill the eggs and lice. These can be purchased without a prescription. Follow the directions carefully.

14. Machine wash all linens, stuffed animals, or any other items with which the lice may have come in contact. Wash in hot, soapy water. D ry all linens in a hot dryer for at least 30 minutes.

15. Items that can not be washed must be taken to the dry cleaner or wrapped and sealed in a plastic bag for 14 days.

16. Clean all hair accessories well.

17. Vacuum all furniture.

18. After shampooing as directed, make sure to remove each single nit from each shaft of hair. Any nits left in the hair will hatch and start the cycle over again.

19. If eyelashes are infested, use petrolatum ointment, applied twice daily for up to 8-10 days; nits should be removed mechanically from the eyelashes with a nit comb.