Pubic lice (crabs)

Pubic lice (Crabs)

Image Source: By Doc. RNDr. Josef Reischig, CSc. - Author's archive, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31557499

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).

Egg

Image Source: By KostaMumcuoglu at the English language Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16506825

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. 

Head Lice - A Lousy Problem

Head Lice - A Lousy Problem

Image source:   By Gilles San Martin - originally posted to Flickr as Male human head louse, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=11208622

1. Three types of sucking lice infest humans: the body louse, the head louse and the crab louse or pubic louse.

2. The head louse and the body louse are physically indistinguishable, but are easily distinguished from the crab louse. Head lice (also known as "head louse") are small insects that live in people's hair and feed on their blood. 

3. Lice glue their eggs (also known as "nits") to hair so they cannot be brushed or shaken off easily. Lice eggs take about six to nine days to hatch. After they have hatched they take about seven or more days to become egg-laying adults. 

4. Lice die very quickly (usually about two days) without feeding and cannot live for very long away from a person's head.

5. They need blood to survive and can live up to 30 days on the head but will die within 1-2 days if they fall off the head.

6. Head lice is also called pediculosis.

Life cycle

Image Source: By CDC - Centers for Disease Control and Prevention. http://phil.cdc.gov/phil/home.asp ID# 6816, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3997380

7. Head lice are not a major public health concern because they do not spread illness or disease.

8. Head lice can be a bother because of the discomfort they can cause and how easily they are spread from person to person.

99. Head lice are not caused by being dirty. Anyone who has hair can get head lice. 

10. Head lice can move quickly on dry hair making them hard to see. 

11. Head lice do not jump or fly or swim. 

12. Head lice bites can make the scalp itchy but they do not cause disease. 

13. Adult head lice lay about 10 eggs (called nits) every day. These nits are stuck to the hair near the scalp. After the head lice hatch, the empty shell of the nit stays stuck to the hair.

Nit

Image Source: By English wikipedia, Fig.3.Louse_egg.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3945597

14. Head lice eggs hatch in seven to nine days into the first nymph stage, which looks like a miniature adult. The nymph takes a blood meal by biting the scalp soon after hatching and will feed every three to six hours. In about nine days, the louse will have passed through two more nymphal stages and reach the adult stage. The adult will stay on the head for its entire life.

15. You can find lice anywhere on the head. Look behind the ears and the back of the neck. 

16. Lice can vary in colour from tan, brown or gray. 

17. You cannot get rid of lice with a hair brush or with a hair dryer. 

18. You can get head lice by touching heads with someone who has head lice, or by sharing combs, brushes, hats, headsets or helmets. 

19. Head lice are common where children play or work closely together. 

20. The best way to find head lice is by using a fine toothed lice comb on hair that is dry, wet or wet with conditioner. 

21. Only treat when you find a live louse on the head.

22. Pets cannot get head lice and people cannot get head lice from pets.

23. Head to head contact with someone who has head lice.

24. Sharing things that are in direct contact with a person’s hair such as combs, brushes, barrettes, ribbons, caps, hats, scarves, helmets, towels, pillows and coats.

25. Children age 5 to 12 get lice more easily because their heads often touch when they play together.

26. Combing with a nit comb-A nit comb can sometimes be effective in removing viable nits and lice. Nits that are more than ¼ inch from the scalp are not likely to be viable and need not be removed. Comb daily until no live lice are discovered for 2 weeks. Recheck in 2-3 weeks after you think all lice are gone. 

27. Over-the-counter lice shampoo-As with all drugs, directions must be followed exactly. These products should be rinsed from the hair over a sink rather than shower or bath to limit exposure to the body. A second treatment may be required in about 10 days. 

288. Prescription lice shampoo medications-These products contain other insecticides that require greater care for treatments and should be used only under a physician’s care and only if live lice persist following treatment with the over-the-counter products. Parents should be advised to discuss with their health care provider specific instructions for use of these products, potential risks and benefits, and other possible treatment recommendations. 

29. A number of household products such as mayonnaise, petroleum jelly, olive oil, tea tree oil, hair gel and vinegar or wet combing have been suggested as a treatment. These products show little proof of killing head lice and are not as effective as head lice shampoo.

30.Wash clothing and bedding used in the last 3 days by the affected person in hot water and dry in a hot dryer. 

31. Place items that cannot be washed in a sealed bag for two weeks.

32. Put all combs, brushes and hair accessories in hot, soapy water.