The brown recluse spider is a venomous spider, Loxosceles reclusa, of the family Sicariidae (formerly of the family Loxoscelidae). It is usually between ¼ and ¾ inch (6-20mm) but may grow larger. It is brown and usually has markings on the dorsal side of its cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nickname 'fiddleback spider' or 'violin spider'. Coloring varies from light tan to brown and the violin marking may not be visible. Since the 'violin pattern' is not diagnostic, and other spiders may have similar marking (i.e. cellar spiders (Pholcidae family) and pirate spiders (Mimetidae family)), for purposes of identification it is far more important to examine the eyes. Differing from most spiders, which have 8 eyes, recluse spiders have 6 eyes arranged in pairs (dyads) with one median pair and 2 lateral pairs. Only a few other spiders have 3 pairs of eyes arranged this way (e.g., scytodids), and recluses can be distinguished from these as recluse abdomens have no coloration pattern nor do their legs, which also lack spines.[1] Recluse spiders build irregular webs that frequently include a shelter consisting of disorderly threads. These spiders frequently build their webs in woodpiles and sheds, closets, garages, and other places that are dry and generally undisturbed. Unlike most web weavers, they leave these webs at night to hunt. As indicated by its name, this spider is not aggressive and usually bites only when pressed against human skin, such as when tangled up within clothes, bath towels, or in bedding.[5]. In fact, many wounds that are necrotic and diagnosed as brown recluse bites can actually be methicillin resistant Staphylococcus aureus (MRSA). Actual brown recluse bites are rare. Brown recluse bites may produce a range of symptoms known as loxoscelism. There are two types of loxoscelism: cutaneous (skin) and systemic (viscerocutaneous). Most bites are minor with no necrosis. However, a small number of bites produce severe dermonecrotic lesions, and, sometimes, severe systemic symptoms, including organ damage. Rarely, the bite may also produce a systemic condition with occasional fatalities. (For a comparison of the toxicity of several kinds of spider bites, see the list of spiders having medically significant venom.) A minority of bites form a necrotizing ulcer that destroys soft tissue and may take months and very rarely years to heal, leaving deep scars. There have been no known cases of actual brown recluse bites sites taking years to heal and can usually be attributed to a systemic infection or disease such as diabetes. The damaged tissue will become gangrenous and eventually slough away. The initial bite frequently cannot be felt and there may be no pain, but over time the wound may grow to as large as 10 inches (25 cm) in extreme cases. Bites usually become painful and itchy within 2 to 8 hours, pain and other local effects worsen 12 to 36 hours after the bite with the necrosis developing over the next few days.[6] Serious systemic effects may occur before this time, as the venom spreads throughout the body in minutes. Mild symptoms include nausea, vomiting, fever, rashes, and muscle and joint pain. Rarely more severe symptoms occur including hemolysis, thrombocytopenia, and disseminated intravascular coagulation.[7] Debilitated patients, the elderly, and children may be more susceptible to systemic loxoscelism. Deaths have been reported for both the brown recluse and the related South American species L. laeta and L. intermedia. How to tell that you do NOT have a brown recluse spider bite is easy. If your wound is weeping or moist and red looking, it is not L. Reclusa because the venom actually seals off the capillaries and produces a dry wound. Secondly, if there is a lump or swelling involved, this is usually indicative of another arachnid or insect as the venom of a recluse produces no swelling (Cite-Vetter).