|
Loxoscelism is a condition occasionally produced by the bite of the recluse spiders (genus ''Loxosceles''). The area becomes dusky and becomes a deep open sore as the skin around the bite dies (necrosis). It is the only proven type of necrotic arachnidism in humans. While there is no known therapy effective for loxoscelism, there has been research on antibiotics, surgical timing, hyperbaric oxygen, potential antivenoms and vaccines.〔 Because of the number of diseases that may mimic loxoscelism, it is frequently misdiagnosed by physicians. Loxoscelism was first described in the United States in 1879 in Tennessee. 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. ''Loxosceles reclusa'' has a limited habitat that includes the Southeast United States. In South America, ''L. laeta'', ''L. intermedia'' (found in Brazil and Argentina), and ''L. gaucho'' (Brazil) are the three species most often reported to cause necrotic bites.〔 ==Pathophysiology== Loxoscelism may present with local and whole-body symptoms: *Necrotic cutaneous loxoscelism is the medical term for the reaction most common in loxoscelism. It is characterized by a localized gangrenous slough at the site of bite. The majority of ''Loxosceles'' bites result in minor skin irritation that heals in one week. Severe reactions, while rare, may produce painful ulcerative lesions up to across.〔 Such lesions often heal within 6 to 8 weeks, and can leave lasting scars. *Viscerocutaneous loxoscelism refers to the combination of local and systemic manifestations that occur infrequently after ''Loxosceles'' bites. Symptoms include low energy, nausea and vomiting, and fever. Destruction of blood cells (hemolytic anemia) may require transfusion and injure the kidney. Consumption of clotting factors (so-called disseminated intravascular coagulation ()) and destruction of platelets (thrombocytopenia) is reported most often in children. DIC may lead to dangerous bleeding. Occasionally, acute kidney failure may develop from myonecrosis and rhabdomyolysis, leading to coma.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「loxoscelism」の詳細全文を読む スポンサード リンク
|