The brown recluse spider lives inside houses as well as in its surroundings. Inside homes, the arachnid lives in dark places, such as cracks, corners, seldom used clothes, curtains and inside furniture. Yet, it is very common for a spider to get trapped in showers and bathtubs because of their smooth surface, and there have been lots of cases in which spiders bit the legs of a person who was having a bath. Outdoors, the BRS is usually located underneath rocks or within hollow woods. If you live in areas where the BRS lives, you must be careful when manipulating garden objects such as boxes, piles of wood, pots, etc.
In the United States, reports of severe envenomations by brown spiders began to appear in the late 1800s, and today, in endemic areas, brown spiders continue to be of significant clinical concern.
Of the 13 species of Loxosceles in the United States, at least 5 have been associated with necrotic arachnidism. Loxosceles reclusus, or the brown recluse spider, is the spider most commonly responsible for this injury.
Dermonecrotic arachnidism refers to the local skin and tissue injury noted with this envenomation. Loxoscelism is the term used to describe the systemic clinical syndrome caused by envenomation from the brown spiders.
Brown recluse spider bites can cause significant cutaneous injury with tissue loss and necrosis. Less frequently, more severe reactions develop, including systemic hemolysis, coagulopathy, renal failure, and, rarely, death.
Brown recluse venom, like many of the other brown spider venoms, is cytotoxic and hemolytic. It contains at least 8 components, including enzymes such as hyaluronidase, deoxyribonuclease, ribonuclease, alkaline phosphatase, and lipase. Sphingomyelinase D is thought to be the protein component responsible for most of the tissue destruction and hemolysis caused by brown recluse spider envenomation. The intense inflammatory response mediated by arachidonic...