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Loxoscelism

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Loxoscelism
Dermonecrosis, a hallmark of loxoscelism
SpecialtyEmergency medicineEdit this on Wikidata
Scarring from a recluse bite after four months

Loxoscelism(/lɒkˈsɒsɪlɪzəm/) is a condition occasionally produced by thebiteof therecluse spiders(genusLoxosceles). The area becomes dusky and a shallow open sore forms as the skin around the bite dies (necrosis). It is the only proven type ofnecroticarachnidismin humans.[1][a]While there is no known therapy effective for loxoscelism, there has been research on antibiotics, surgical timing, hyperbaric oxygen, potentialantivenomsand vaccines.[1]Because of the number of diseases that may mimic loxoscelism, it is frequently misdiagnosed by physicians.[b]

Loxoscelism was first described in the United States in 1879 in Tennessee.[2]Although there are up to 13 differentLoxoscelesspecies in North America (11 native and two nonnative),Loxosceles reclusais the species most often involved in seriousenvenomation.L. reclusahas a limited habitat that includes the Southeast United States. In South America,L. laeta,L. intermedia(found in Brazil and Argentina), andL. gaucho(Brazil) are the three species most often reported to cause necrotic bites.

Pathophysiology

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Loxoscelism may present with local and whole-body symptoms:

  • Necrotic cutaneous loxoscelismis the medical term for the skin only reaction of loxoscelism. It is characterized by a localized necrotic wound at the site of bite. The majority ofLoxoscelesbites result in minor skin irritation that heals in one week.[1]Other lesions often need 6 to 8 weeks to heal, and can leave lasting scars.[citation needed]
  • Viscerocutaneous loxoscelismrefers to the combination of skin and other organ manifestations. This occurs infrequently afterLoxoscelesbites. Symptoms include low energy, nausea and vomiting, and fever. Destruction of blood cells (hemolytic anemia) may require transfusion and injure the kidney.[3]: 455 Consumption of clotting factors (so-calleddisseminated intravascular coagulation[ "DIC" ]) and destruction of platelets (thrombocytopenia) is reported most often in children. DIC may lead to dangerous bleeding. Occasionally,acute kidney failuremay develop frommyonecrosisandrhabdomyolysis,leading to coma.[1]

Loxosceles toxins

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Loxoscelesvenom has several toxins; the most important for necrotic arachnidism is the enzymesphingomyelinase D.It is present in all recluse species to varying degrees and not all are equivalent. This toxin is present in only one other known spider genus (Sicarius).[1]The toxin dissolves the structural components of the cell membrane generating ring forms that perhaps act as a trigger for cellular self-destruction.[4]The area of destruction is limited to the presence of the enzyme which cannot reproduce.[citation needed]

Diagnosis

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The spider biting apparatus is short and bites are only possible in experimental animals with pressure on the spider's back. Thus many bites occur when a spider is trapped in a shirt or pant sleeve. There is no commercial chemical test to determine if the venom is from abrown recluse.The bite itself is not usually painful. Manynecrotic lesionsare erroneously attributed to the bite of the brown recluse. (See Note). Skin wounds are common and infections will lead to necrotic wounds, thus many severe skin infections are attributed falsely to the brown recluse.[5]Many suspected bites occurred in areas outside of its natural habitat.[6]A wound found one week later may be misattributed to the spider. The diagnosis is further complicated by the fact that no attempt is made to positively identify the suspected spider. Because of this, other, non-necrotic species are often misidentified as a brown recluse.[7]Several certifiedarachnologistsare able to positively identify a brown recluse specimen on request.[8]

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.[9]

Themnemonic"NOT RECLUSE"has been suggested as a tool to help professionals more objectively exclude skin lesions that were suspected to be loxosceles.[10] 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)[11]

Systemic loxocelism, a rare but severe illness caused by a brown recluse bite, can be diagnosed through urinalysis. However, a blood test for elevated lactate dehydrogenase and total bilirubin have been shown to be a more sensitive test.[12]

Treatment

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Despite being one of the few medically important spider bites, there is no established treatment for the bite of a Loxosceles spider. Physicians wait for the body to heal itself, and assist with cosmetic appearance. There are, however, some remedies currently being researched.[13]

Anti-venoms

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Anti-venoms are commercially prepared antibodies to toxins in animal bites. They are specific for each bite. There are severalanti-venomscommercially available in Brazil, which have been shown to be effective in controlling the spread of necrosis in rabbits.[14]When administered immediately, they can almost entirely neutralize any ill effects. If too much time is allowed to pass, the treatment becomes ineffective. Most victims do not seek medical attention within the first twelve hours of being bitten, and these anti-venoms are largely ineffective after this point. Because of this, anti-venoms are not being developed more widely. They have, however, been proven to be very effective if administered in a timely manner and could be utilized in Brazil as a legitimate technique.[citation needed]

Surgical treatment

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In cases where a largedermonecrotic lesionhas developed, the dead tissue can be surgically removed. Skin grafting may ultimately be needed to cover this defect.[citation needed]

Species implicated

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Loxosceles

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It is suspected that most if not all species of the genusLoxosceleshave necrotic venom. Over fifty species have been identified in the genus, but significant research has only been conducted on species living in close proximity to humans.[15]

Loxosceles reclusa(Brown recluse spider)

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Among the spiders bearing necrotic venom, thebrown recluseis the most commonly encountered by humans. The range of the brown recluse spider extends from southeastern Nebraska to southernmost Ohio and south into Georgia and most of Texas. It can be distinguished by violin shaped markings on its back. The long spindly ( "haywire" ) legs have no spines or banding pattern. The brown recluse has six eyes, arranged in pairs, an uncommon arrangement but not exclusive. However, many lesser known species of the Loxosceles genus are believed to have similar venoms.L. reclusais a very non-aggressive species.[16]There have been documented cases of homes having very large populations of brown recluse spiders for many years without any of the human inhabitants being bitten. For this reason,L. reclusabites are relatively rare, but, because its range overlaps human habitation, its bite is the cause of loxoscelism in North America.[citation needed]

Loxosceles laeta(Chilean recluse spider)

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Loxosceles laeta,commonly known as the Chilean recluse spider, is widely distributed in South and Central America. Necrotic skin lesions and systemic loxoscelism are well described with this species. It can be transported by people, and populations in solitary buildings are noted in North America, Finland, and Australia.[17]L. laetahas been documented at elevations between 200m and 2340m.[18]Thelaetais cryptozoic, meaning it lives in dark concealed places. This can often mean piles of wood or brick.

Loxosceles deserta(Desert recluse)

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L. desertais found in the Southwest United States. Human interactions with it are rare, because it usually is only found in native vegetation. It is not usually found within heavily populated areas, but its range does come near these areas. It is considered medically unimportant due to the low likelihood of human-to-spider encounters.[19]

Other genera

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Lampona cylindrata(White-tailed spider)

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Thewhite-tailed spider,found principally in Australia, was formerly blamed for a series of illnesses including necrotic arachnidism. This used to be part of academic and popular belief, but several reviews of the data have demonstrated no necrosis.[20]

Cheiracanthium inclusum(Yellow sac spider)

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Cheiracanthium inclusum,also known as the black-footed yellow sac spider, has been implicated in necrotic skin lesions.C. inclusum'svenom has been claimed to be weakly necrotic, but arachnologists contest this assertion.[21]This spider can be found all over North, Central, and South America, as well as in The West Indies. It is often encountered by people indoors and outdoors alike.[citation needed]

Eratigena agrestis(Hobo spider)

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Many necrotic lesions in the northwestern United States have been attributed to spider bite. The Centers for Disease Control made a survey[22]as brown recluses are not found in the Pacific Northwest. However, there is a large population of theE. agrestis.[23]This fact has led many to believe that the bite of the hobo spider is also necrotic. Critics note that this evidence is only circumstantial.[5]The species is of European origin and never known to have caused such effects over the hundreds of years that it has been known by, interacted with, and bitten people. Claims of a medically significant bite should be regarded as a myth.[24][25]

Lycosaspp (Wolf spiders)

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One of the pioneers[who?]in antivenom studies in Brazil in the 1920s first focused onLycosaspecies as causes for illness and widespread necrotic lesions. This belief lasted for 50 years until the wolf spider was exonerated.[26]

See also

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Explanatory notes

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  1. ^The recluse spiders are the only genus definitively shown to cause necrotic bites in humans. The layers of skin die and slough away leaving an ulcer. Since at least 1872, the blanket termnecrotic arachnidismhas been used in the medical literature, often erroneously implicating spiders that do not cause dermal necrosis. Spider species blamed for necrosis in the past have includedwolf spiders,white-tailed spiders,black house spiders,yellow sac spiders,orb weavers,and funnel-weaving spiders such as thehobo spider.[1]
  2. ^Diseases that may cause symptoms similar to loxoscelism include: streptococcal orstaphylococcal infection(particularly bymethicillin-resistantStaphylococcus aureus), herpes simplex, herpes zoster, diabetic ulcer, fungal infection, pyoderma gangrenosum, lymphomatoid papulosis, chemical burn,Toxicodendrondermatitis, squamous cell carcinoma, neoplasia, localized vasculitis, syphilis, Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema nodosum, erythema multiforme, gonococcemia, purpura fulminans, sporotrichosis, Lyme disease, cowpox, and anthrax.[1]

References

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  1. ^abcdefgSwanson, David L.; Vetter, Richard S. (2006)."Loxoscelism"(PDF).Clinics in Dermatology.24(3): 213–21.doi:10.1016/j.clindermatol.2005.11.006.PMID16714202.Archived fromthe original(PDF)on 30 June 2019.Retrieved12 April2011.
  2. ^Appel, MH; Bertoni da Silveira, R; Gremksi, W; Veiga, SS (2005)."Insights into brown spider and loxoscelism"(PDF).Invertebrate Survival Journal.2(2). University of Modena and Reggio Emilia: 152–158.ISSN1824-307X.Archived fromthe original(PDF)on 22 July 2011.Retrieved12 April2011.
  3. ^James, William D.; Berger, Timothy G. (2006).Andrews' Diseases of the Skin: clinical Dermatology.Saunders Elsevier.ISBN0-7216-2921-0.
  4. ^Lajoie, Daniel M.; Zobel-Thropp, Pamela A.; Kumirov, Vlad K.; Bandarian, Vahe; Binford, Greta J.; Cordes, Matthew H. J.; Gasset, Maria (29 August 2013)."Phospholipase D Toxins of Brown Spider Venom Convert Lysophosphatidylcholine and Sphingomyelin to Cyclic Phosphates".PLOS ONE.8(8): e72372.Bibcode:2013PLoSO...872372L.doi:10.1371/journal.pone.0072372.PMC3756997.PMID24009677.
  5. ^abVetter Richard S (2000)."Medical Myth: Myth: idiopathic wounds are often due to brown recluse or other spider bites throughout the United States".Western Journal of Medicine.173(5): 357–358.doi:10.1136/ewjm.173.5.357.PMC1071166.PMID11069881.
  6. ^Vetter Richard S., Edwards G. B., James Louis F. (2004)."Reports of envenomation by brown recluse spiders (Araneae: Sicariidae) outnumber verifications of Loxosceles spiders in Florida".Journal of Medical Entomology.41(4): 593–597.doi:10.1603/0022-2585-41.4.593.PMID15311449.{{cite journal}}:CS1 maint: multiple names: authors list (link)
  7. ^Vetter Richard S (2009). "Arachnids misidentified as brown recluse spiders by medical personnel and other authorities in North America".Toxicon.54(4): 545–547.doi:10.1016/j.toxicon.2009.04.021.PMID19446575.
  8. ^Vetter, Rick."Myth of the Brown Recluse Fact, Fear, and Loathing".UCR Spiders Site.Archived fromthe originalon 10 April 2012.Retrieved10 March2014.
  9. ^Vetter, RS (15 September 2009). "Arachnids misidentified as brown recluse spiders by medical personnel and other authorities in North America".Toxicon.54(4): 545–7.doi:10.1016/j.toxicon.2009.04.021.PMID19446575.
  10. ^Stoecker, William V.; Vetter, Richard S.; Dyer, Jonathan A. (2017). "NOT RECLUSE—A Mnemonic Device to Avoid False Diagnoses of Brown Recluse Spider Bites".JAMA Dermatology.153(5): 377–378.doi:10.1001/jamadermatol.2016.5665.PMID28199453.
  11. ^Stoecker, William V.; Vetter, Richard S.; Dyer, Jonathan A. (1 May 2017). "NOT RECLUSE—A Mnemonic Device to Avoid False Diagnoses of Brown Recluse Spider Bites".JAMA Dermatology.153(5): 377–378.doi:10.1001/jamadermatol.2016.5665.PMID28199453.
  12. ^Jacobs, Jeremy; Bastarache, Richard S.; Thompson, Mary Ann (13 October 2021). "Laboratory Predictors of Hemolytic Anemia in Patients With Systemic Loxoscelism".Am J Clin Pathol.157(4): 566–572.doi:10.1093/ajcp/aqab169.PMID34643670.
  13. ^Streeper, Robert T.; Izbicka, Elzbieta (January 2022)."Diethyl Azelate for the Treatment of Brown Recluse Spider Bite, a Neglected Orphan Indication".In Vivo.36(1): 94–102.doi:10.21873/invivo.12679.PMC8765177.PMID34972703.
  14. ^Barbaro, K.C.; Knysak, I.; Martins, R.; Hogan, C.; Winkel, K. (2005). "Enzymatic Characterization, Antigenic Cross-Reactivity And Neutralization of Dermonecrotic Activity of Five Loxosceles Spider Venoms of Medical Importance in the Americas".Toxicon.45(4): 489–99.doi:10.1016/j.toxicon.2004.12.009.PMID15733571.
  15. ^Vetter, Richard S. (2015).The Brown Recluse Spider.Ithaca, NY.ISBN978-0801479854.{{cite book}}:CS1 maint: location missing publisher (link)
  16. ^Fisher, R. G.; Kelly, P.; Krober, M. S.; Weir, M. R.; Jones, R. (1994)."Necrotic Arachnidism".The Western Journal of Medicine.160(6): 570–2.ISSN0093-0415.PMC1022570.PMID8053187.
  17. ^https://www.researchgate.net/publication/284124826.{{cite journal}}:Cite journal requires|journal=(help);Missing or empty|title=(help)
  18. ^Gonçalves-de-Andrade, Rute M.; Tambourgi, Denise V. (2003)."First Record On Loxosceles Laeta (Nicolet, 1849) (Araneae, Sicariidae) In The West Zone Of São Paulo City, São Paulo, Brazil, And Considerations Regarding Its Geographic Distribution".Revista da Sociedade Brasileira de Medicina Tropical.36(3): 425–6.doi:10.1590/S0037-86822003000300019.PMID12908048.
  19. ^Vetter, Richard S. (2015).The Brown Recluse Spider.Cornell University Press.ISBN978-0801479854.
  20. ^White, Julian; Weinstein, Scott A. (2014). "A phoenix of clinical toxinology: White-tailed spider (Lampona spp.) bites. A case report and review of medical significance".Toxicon.87:76–80.doi:10.1016/j.toxicon.2014.05.021.PMID24923740.
  21. ^Vetter Richard S.; et al. (2006)."Verified bites by yellow sac spiders (genus Cheiracanthium) in the United States and Australia: Where is the necrosis?".American Journal of Tropical Medicine and Hygiene.74(6): 1043–8.doi:10.4269/ajtmh.2006.74.1043.PMID16760517.
  22. ^"Necrotic Arachnidism -- Pacific Northwest, 1988-1996".CDC MMWR.
  23. ^Baird, Craig R.; Stoltz, Robert L. (2005). "Range Expansion of the Hobo Spider,Tegenaria agrestis,in the Northwestern United States (Araneae, Agelenidae) ".{{cite journal}}:Cite journal requires|journal=(help)
  24. ^Diaz James H (2005)."Most necrotic ulcers are not spider bites".The American Journal of Tropical Medicine and Hygiene.72(4): 364–367.doi:10.4269/ajtmh.2005.72.364.
  25. ^Bennett Robert G., Vetter Richard S. (2004)."An approach to spider bites. Erroneous attribution of dermonecrotic lesions to brown recluse or hobo spider bites in Canada".Canadian Family Physician.50(8): 1098–1101.PMC2214648.PMID15455808.
  26. ^Lucas, Sylvia M. (June 2015)."The history of venomous spider identification, venom extraction methods and antivenom production: a long journey at the Butantan Institute, São Paulo, Brazil".Journal of Venomous Animals and Toxins Including Tropical Diseases.21(1): 21.doi:10.1186/s40409-015-0020-0.ISSN1678-9199.PMC4470033.PMID26085831.
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