List of medically significant spider bites
[2] In the last century, both white tailed and wolf spiders were considered medically significant, only to be recanted.
[3] Only ten genera (Phoneutria, Atrax, Latrodectus, Loxosceles, Sicarius, Hexophthalma, Hadronyche, Illawarra, Macrothele and Missulena) are considered medically significant.
In this case, the high levels of serotonin contained in the venom, plus at minimum-strong chelicera, will contribute to deliver a very painful bite.
[8] Scientists are attempting to create an erectile dysfunction treatment that can be combined with other medicines out of the peptide that causes this reaction.
[13][14] The related genus Hadronyche is represented by 32 other dangerous species in eastern Australia, including Queensland and Tasmania.
Some species, especially those in North America, have no spot on their backs, with the hourglass becoming visible only when the spider hangs upside-down, and can thus be mistaken for their less dangerous cousins, which is especially true in males.
The Australian red-back and North American widow species live near humans and bites are frequent, numbering thousands yearly.
The bite of Steatoda grossa may cause nausea, widespread but short lived intense pain, muscle spasms, fatigue, necrotizing or infected wound sites and malaise;[22] the medical community now refers to the symptoms of Steatoda bites as steatodism.
[23] Other spiders in this genus with potentially medically significant venom include two chiefly European varieties, S. paykulliana and S. nobilis, and a species found mainly in New Zealand and South Africa, S.
Members of this genus are characterized by the "D" shape of the cephalothorax, and the way the relatively straight line thus formed is mirrored by the blunt forward surface of the abdomen.
Other genera in this family generally have cephalothoraxes that are more oval in shape or even rather round, and that give the appearance of two body parts that are joined by a small connector.
[26] Due to small fangs, bites happen when trapped against one's skin by clothing, bed sheets, etc.
A minority of bites form a necrotizing ulcer that destroys soft tissue and may take months and, on very rare occasions, years to heal, leaving deep scars.
[35] The six-eyed sand spiders of southern Africa in the genus Hexophthalma and Sicarius from South America inject a cytotoxic venom, that contains sphingomyelinase D,[36] for which there is currently no antivenom.
However, most bite victims suffer only local pain and bleeding, a few more have limited neurotoxic symptoms (tingling, racing heart, more widespread pain), and there have been several recorded bites by this spider producing severe symptoms requiring medical treatment.
Trapdoor spiders, many of which resemble tarantulas but are shinier and less hairy, also have large fangs that deliver painful bites, but have very mild venom.
The primary defense deployed by these spiders is by means of urticating hairs, which can cause irritant symptoms in humans.
Symptoms include localized pain and swelling, exhaustion, moderate to severe muscle cramping, labored breathing and fever, sometimes delayed days after the initial bite.
Pterinochilus murinus, Lampropelma nigerrimum, and members of the genera Stromatopelma, Heteroscodra, and Selenocosmia are other old world tarantulas that are noted for possessing particularly strong venom which tends to cause severe muscle spasms.
The Centers for Disease Control[45] blamed the hobo spider in three reports of necrotic "bites" in the Pacific Northwest of the United States between 1988 and 1996.
Studies performed by arachnologist Darwin Vest reported that this spider's venom caused significant necrotic effects in laboratory animals.
[46][47] Many agricultural authorities have published the advice that this species is potentially harmful, and medical personnel in the western United States and Canada have been advised to consider hobo spider bites when patients present with necrotic wounds.
Attempts to replicate Vest's study that reported necrotic effects of the venom have failed, thus casting the "dangerous" status of this spider into doubt.
History of medicine believe the confusion came from workers in the fields would suffer bites, and observe large, conspicuous, hairy spiders in the area.
Lycosa raptoria of South America has been reported to have caused a painful bite followed by intense tissue swelling and in some cases either mild systemic effects or a necrotic lesion.
), indigenous to Australia and introduced to New Zealand, have been blamed for a necrotic bite, producing symptoms similar to a brown recluse.
[3] A study of 130 white-tailed spider bites found no necrotic ulcers or confirmed infections; only a red mark, local swelling, and itchiness.
[52][53] This study was cited by numerous other papers and led to the widespread belief that yellow sac spiders (Cheiracanthium sp.)
In the Middle East, it is common belief among some American soldiers stationed there that Solifugae will feed on living human flesh.
However, due to the large size of their jaws, bites by Solifugae can cause significant wounds, which should be treated accordingly to avoid infection.
