Brown Recluse Spider

     The Brown Recluse Spider is a venomous spider. It can cause significant cutaneous injury with tissue loss and necrosis. You can find the Brown Recluse in the United States from the east to west coast, and sometimes in the south. The Black Recluse is different from most spiders because instead of having 8 eyes, it only has 6 eyes that are arranged in pairs. One pair is on front and another pair on either side. It usually has a shy and nonaggressive behavior, but occasionally bites humans because they share the same habitat. It usually just bites when it is being disturbed. They roam at night and hide during they day. They can survive six months without food or water. It bites when it is caught between a part of the body and another surface like when children are playing under house furniture, while a person is sleeping and rolls on to where it is, or when getting dressed with clothes or shoes where the spider has hidden itself.
     The Brown Recluse Spider's venom in extremely poisonous, even more than a rattlesnake, but when they bite, they cause less disease than rattlesnakes. The venom from this spider is toxic to cells and tissues. There are some secondary results that are very rare, but can still happen. The destruction of red blood cells, low platelet count, blood clots in the capillaries and loss of ability to form clots where needed, acute renal failure (kidney damage), coma, and death.  The  symptoms of Brown Recluse spider bites are severe pain at the bite about 4 hours later, severe itching, nausea, vomiting, fever, and muscle pain. The bite is usually red upon close inspection and may reveal fang marks. Most commonly, the bite will become hard and heal with a little scaring over the next few weeks or days. Occasionally, the local reaction will be more severe with erythema and blistering, sometimes leading to blue discoloration, and ultimately leading to a necrotic lesion and scarring. Signs that may be present are blistering, death of skin and subcutaneous fat, and severe destructive necrotic lesions with deep wide borders.
    So researching the Brown Recluse Spider, i can conclude that this spider isn't very common where we live, but if you get bit by one, it can be very serious and dangerous.

http://www.emedicinehealth.com/spider_bite_brown_recluse_spider_bite/page3_em.htm