Numerous (should be solitary), Occurrence (wrong geography) Timing (wrong season), Red Center (center should be black), Elevated (should be shallow depression), Chronic, Large (more than 10 cm), Ulcerates too quickly (less than a week), Swollen, Exudative (there should be no pus, it should be dry) The mnemonic " NOT RECLUSE" has been suggested as a tool to help professionals more objectively exclude skin lesions that were suspected to be loxosceles. Reports of presumptive brown recluse spider bites reinforce improbable diagnoses in regions of North America where the spider is not endemic such as Florida, Pennsylvania, and California. Several certified arachnologists are able to positively identify a brown recluse specimen on request. Because of this, other, non-necrotic species are frequently mistakenly identified as a brown recluse. The diagnosis is further complicated by the fact that no attempt is made to positively identify the suspected spider. A wound found one week later may be misattributed to the spider. Many suspected bites occurred in areas outside of its natural habitat. Skin wounds are common and infections will lead to necrotic wounds, thus many severe skin infections are attributed falsely to the brown recluse. Many necrotic lesions are erroneously attributed to the bite of the brown recluse. There is no commercial chemical test to determine if the venom is from a brown recluse. Thus many bites occur when a spider is trapped in a shirt or pant sleeve. The spider biting apparatus is short and bites are only possible in experimental animals with pressure on the spider's back. The area of destruction is limited to the presence of the enzyme which cannot reproduce. The toxin dissolves the structural components of the cell membrane generating ring forms that perhaps act as a trigger for cellular self-destruction. This toxin is present in only one other known spider genus ( Sicarius). It is present in all recluse species to varying degrees and not all are equivalent. Loxosceles venom has several toxins the most important for necrotic arachnidism is the enzyme sphingomyelinase D. Occasionally, acute kidney failure may develop from myonecrosis and rhabdomyolysis, leading to coma. : 455 Consumption of clotting factors (so-called disseminated intravascular coagulation ) and destruction of platelets ( thrombocytopenia) is reported most often in children. Destruction of blood cells ( hemolytic anemia) may require transfusion and injure the kidney. Symptoms include low energy, nausea and vomiting, and fever. This occurs infrequently after Loxosceles bites. Viscerocutaneous loxoscelism refers to the combination of skin and other organ manifestations.Other lesions often need 6 to 8 weeks to heal, and can leave lasting scars. The majority of Loxosceles bites result in minor skin irritation that heals in one week. It is characterized by a localized necrotic wound at the site of bite. Necrotic cutaneous loxoscelism is the medical term for the skin only reaction of loxoscelism.Loxoscelism may present with local and whole-body symptoms: gaucho (Brazil) are the three species most often reported to cause necrotic bites. intermedia (found in Brazil and Argentina), and L. reclusa has a limited habitat that includes the Southeast United States. Although there are up to 13 different Loxosceles species in North America (11 native and two nonnative), Loxosceles reclusa is the species most often involved in serious envenomation. Loxoscelism was first described in the United States in 1879 in Tennessee. Because of the number of diseases that may mimic loxoscelism, it is frequently misdiagnosed by physicians. While there is no known therapy effective for loxoscelism, there has been research on antibiotics, surgical timing, hyperbaric oxygen, potential antivenoms and vaccines. It is the only proven type of necrotic arachnidism in humans. The area becomes dusky and a shallow open sore forms as the skin around the bite dies ( necrosis). Loxoscelism ( / l ɒ k ˈ s ɒ s ɪ l ɪ z əm/) is a condition occasionally produced by the bite of the recluse spiders (genus Loxosceles). Scarring from a recluse bite after four months
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