Editing Redback spider (section)

===Signs and symptoms===
{{Main|Latrodectism}}
Envenomation from a redback spider bite produces a syndrome known as [[latrodectism]]. A small but significant percentage of people bitten develop significant pain or systemic symptoms.<ref name=isbister2006/> The diagnosis is made from the clinical condition, often based on the victim being aware of a bite and ideally with identification of the spider. Laboratory tests are rarely needed and there is no specific test for the venom or latrodectism.<ref name="lancet"/>

The redback's small size means that swelling or puncture marks at the bite site are uncommon. The bite may be painful from the start, but more often only feels like a pinprick or mild burning sensation.<ref name=Ibister2004/> Within an hour, a more severe local pain may develop with local sweating and sometimes [[piloerection]] (goosebumps)—these three symptoms together are a classic presentation of redback spider envenomation.{{sfn|White|2013|p=183}} Pain, swelling and redness can spread proximally up a limb or away from the bite site<ref name="Slaughter">{{cite journal|author1=Slaughter, R. J. |author2=Beasley, D. M. |author3=Lambie, B. S. |author4=Schep, L. J. |title=New Zealand's venomous creatures |journal=[[The New Zealand Medical Journal]] |volume=122 |issue=1290 |pages=83–97 |year=2009 |pmid=19319171 |url=http://www.nzma.org.nz/journal/122-1290/3494/ |url-status=dead |archive-url=https://web.archive.org/web/20110417090807/http://www.nzma.org.nz/journal/122-1290/3494/ |archive-date=17 April 2011 }}</ref><ref name=Ibister2004>{{cite journal|last=Isbister|first=Geoffrey K.|author2=White, Julian |title=Clinical Consequences of Spider Bites: Recent Advances in our Understanding|journal=Toxicon|date=April 2004|volume=43|issue=5|pages=477–92|doi=10.1016/j.toxicon.2004.02.002|pmid=15066408|bibcode=2004Txcn...43..477I |type=Review}}</ref><ref name="lancet"/><!--cites 2 sentences-->
and regional lymph nodes may become painful.<ref name="jelinek1997"/> Some subjects with delayed symptoms may present with a characteristic sweating and pain in the lower limbs,{{sfn|White|2013|p=183}} generally below the knees,<ref name="lancet"/> or a burning sensation in the soles of the feet. This may eventuate even if the person was bitten somewhere else on their body.{{sfn|White|2013|p=183}}<!-- cites previous 1.5 sentences -->

Around one in three subjects develops systemic symptoms;<ref name="lancet"/> after a number of hours, or rarely, delayed for more than 24 hours.<ref name="sutherland"/><ref name=jelinek1989>{{cite journal |author1=Jelinek, G. A. |author2=Banham, N. D. |author3=Dunjey, S. J. |title=Red-back Spider-bites at Fremantle Hospital, 1982–1987|journal=Medical Journal of Australia |volume=150 |issue=12 |pages=693–95 |year=1989 |pmid= 2733615|type=Case report|doi=10.5694/j.1326-5377.1989.tb136762.x |s2cid=204110952 }}</ref> Symptoms typically include nausea, vomiting, abdominal or chest pain, agitation, headache, generalised sweating and [[hypertension]].<ref name="lancet"/>{{sfn|White|2013|p=183}} Other non-specific systemic effects such as malaise and lethargy are also common. Rarely, other effects are reported such as neurological manifestations, fever and priapism (uncontrolled erection of the penis).<ref name=":2" /> Severe pain usually persists for over 24 hours after being bitten. Symptoms of envenomation may linger for weeks or even months.<ref name=Nimorakiotakis/> Rare complications include localised skin infection, seizure, coma, [[pulmonary oedema]], or [[respiratory failure]].<ref name="sutherland"/> Children, the elderly, or those with serious medical conditions are at much higher risk of severe effects resulting from a bite.<ref name="White"/> Infants have died within hours of a bite, but adult fatalities have taken up to 30 days.<ref name=MorningBulletin1954>{{cite news |url=http://nla.gov.au/nla.news-article57311162 |title=Nature Notes Red-backs and Black Widow |newspaper=[[The Morning Bulletin]] |location=Rockhampton, Queensland |date=2 March 1954 |page=6 |publisher=National Library of Australia |access-date=4 September 2013 |archive-date=19 October 2021 |archive-url=https://web.archive.org/web/20211019063040/https://trove.nla.gov.au/newspaper/article/57311162 |url-status=live }}</ref>

Children and infants may be unable to report being bitten, making it difficult to associate their symptoms with a spider bite.<ref name=isbister2006>{{cite journal|last=Isbister |first=Geoffrey K |year=2006 |title=Spider bite: a current approach to management |journal=Australian Prescriber |volume=29 |issue=6 |pages=156–58 |doi=10.18773/austprescr.2006.095 |doi-access=free }}</ref> Symptoms seen in infants include inconsolable crying, refusing to feed and a general [[erythema]]tous rash.{{sfn|White|2013|p=225}}{{efn|Published studies specifically looking at effects in children have been retrospective only and too limited to draw conclusive results.<ref name=Ibister2004/> A ten-year retrospective study of children bitten and admitted to hospital in Perth found that the clinical features resemble those of adult cases, and 21% required antivenom—a rate similar to adult use,<ref>{{cite journal|author1=Mead, H.J. |author2=Jelinek, G.A. |year=1993|title=Red-back Spider Bites to Perth Children, 1979–1988|journal=Journal of Paediatrics and Child Health|volume=29|issue=4|pages=305–08 |doi=10.1111/j.1440-1754.1993.tb00518.x|pmid=8373679 |s2cid=25640556 }}</ref> while a ten-year retrospective study from Alice Springs Hospital found that 83% required antivenom therapy, with irritability, hypertension and sweating as the most common clinical symptoms.<ref name=Trethewy2003>{{cite journal|author1=Trethewy, Christopher E. |author2=Bolisetty, Srinivas |author3=Wheaton, Gavin |year=2003|title=Red-back Spider Envenomation in Children in Central Australia|journal=Emergency Medicine|volume=15|issue=2|pages=170–75|doi=10.1046/j.1442-2026.2003.00435.x|pmid=12675627}}</ref>}} Muscle aches and pains, and neck spasm are often seen in children over four years of age.<ref name=Nimorakiotakis/>

Unlike those of some other spiders, redback bites do not [[necrosis|necrose]].<ref>{{cite journal|last=Young|first=Anna R.|author2=Pincus, Steven J. |title=Comparison of Enzymatic Activity from Three Species of Necrotising Arachnids in Australia: ''Loxosceles rufescens'', ''Badumna insignis'' and ''Lampona cylindrata''|journal=Toxicon|date=February–March 2001|volume=39|issue=2–3|pages=391–400|doi=10.1016/S0041-0101(00)00145-8|pmid=10978759|bibcode=2001Txcn...39..391Y |type=Comparative study}}</ref> <!-- Even envenomated bites do not cause miscarriage of pregnancies, and foetuses are typically unaffected.<ref>{{cite journal|last=Vetter|first=Richard S.|author2=Visscher, P. Kirk |title=Bites and Stings of Medically Important Venomous Arthropods|journal=International Journal of Dermatology|date=July 1998|volume=37|issue=7|pages=481–96|doi=10.1046/j.1365-4362.1998.00455.x|pmid=9679688}}</ref> --> Latrodectism has been misdiagnosed as various medical conditions including [[acute hepatitis]], [[sepsis]], [[testicular torsion]] or an [[acute abdomen]].<ref name=Nimorakiotakis/>