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Infections
STIs Crab Lice
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How would I recognize them?
"Crabs" are members of the lice insect family. They are flat backed, wingless, have large, heavy curved claws and are grayish white in colour.
They are smaller and flatter than head and body lice (1.0 mm-1.2 mm). (This shape when magnified, gives them the appearance of crabs, and the nickname "crabs" or crab lice.)

Where are they found?

  • Primarily in the pubic region of the body where they attach to the short, coarse body pubic hair.
  • They may also infest underarms, mustaches, eyelashes and even eyelids. (Generally, crab lice move about less than head and body lice. If they do move, it is usually only short distances.)

How do crab lice live?

  • Crab lice, like other parasites, depend on their "host" for survival.
  • Their only source of nourishment is human blood.
  • They feed frequently and for lengthy periods of time, 35 to 45 minutes.
  • During this period, they swell up and change colour, a deep rust, which makes them easier to see.
  • Heat is also important to their survival (30o C). When the temperature of their environment rises or drops significantly, the crab lice will leave to seek a new host.

How do you get crab lice?

  • Usually through close physical contact, particularly sexual contact.
  • Can also be transmitted through the interchange of clothing, bedding, towels or contaminated toilet seats. (But this method is less frequent as lice that drop off the host are usually dead or dying and are of little danger. This also applies to crab lice recovered from combing the infested hairy area. They are usually injured and incapable of sustaining life.)

How do I know if I have crab lice?

  • Usually begins with persistent itching which is localized in the genital area. Continuous scratching can cause skin irritation and could lead to infection.
  • Tiny specks of dark brown waste materials are seen on underwear, bed sheet and body skin.
  • You can see the lice themselves which become visible after ingesting blood and may appear as rust brown spots in the genital area.
  • What may also appear like dandruff flakes at the base of pubic hair, are crab lice, eggs called mites, if not removed, they can hatch and start the cycle again.

How are "crabs" treated?
Medicated cream or lotion can be purchased without a prescription at your local drug store. Ask the pharmacist.

How to use these creams or lotions?
They should be applied to cool, dry skin only.

  1. Apply a thin layer of cream or lotion to the hair and skin of the affected and surrounding areas.
  2. Put on freshly cleaned clothing.
  3. After 8 to 12 hours take a bath or shower, washing thoroughly all areas of application.
  4. Again put on freshly cleaned clothing.

Note: Although one application is usually successful, the procedure may be repeated ONCE only, about 7 days after the first application.

All clothing, bed linen, towels, etc. that might have come in contact with the infested person, should be disinfected by washing in very hot water (60o C temperature) or dry cleaned.

When washing and dry cleaning is not possible, such items as upholstery, bedding, blankets, etc., a spray insecticide should be used to ensure total destruction of all crab lice to help prevent the infestation/reinfestation cycle. After the spray has been left on the article the proper length of time, vacuum the article to remove any dead lice/mite. Be sure, then, to remove the filter bag from the vacuum and put it out in the garbage.

Can I get "crabs" again?
Yes!.... There is no permanent prevention with a second infestation the symptoms show up much faster. You would probably begin to itch within a few hours.

To avoid another case of crab lice:

  • Put all clothes which have come in direct contact with the skin (underwear, trousers, shirts, socks, etc.) through a hot cycle in the washing machine. (It is not necessary to treat overcoats, winter jackets or hats.)
  • Do the same to towels and linens.
  • Be sure no members of the family use the same towels or linen, etc. until these items have been put through a hot wash cycle.
  • Wash your hands often, bathe or shower daily, wear clean clothes and do not exchange clothes with others. Sleep in a clean bed.

IT IS VERY IMPORTANT TO PREVENT REINFESTATION!

All members of the family and others who may have had contact with the infested person should be examined and if necessary undergo the same treatment to prevent reinfestation.

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