Armed spider bite: Difference between revisions

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==Background==<ref>Leslie V. Boyer, Greta J. Binford, Janice A. Degan. Spider Bites. Paul S. Auerbach. In: Auerbach’s Wilderness Medicine. 7th Ed. 2017: 1010-1011.</ref>
==Background<ref>Leslie V. Boyer, Greta J. Binford, Janice A. Degan. Spider Bites. Paul S. Auerbach. In: Auerbach’s Wilderness Medicine. 7th Ed. 2017: 1010-1011.</ref>==
[[File:p nigreventer.jpeg|thumb|Phoneutria nigreventer, The Brazilian Wandering Spider]]
*Identification: Brown gray with white spots forming a longitudinal band on the dorsal abdomen and a red-brown brush of hair on the chelicerae. Large in size (4.5-6cm) with 4-5mm fangs.
*Identification: Brown gray with white spots forming a longitudinal band on the dorsal abdomen and a red-brown brush of hair on the chelicerae. Large in size (4.5-6cm) with 4-5mm fangs.
**They do not form webs, but rather are mobile nocturnal hunters
**They do not form webs, but rather are mobile nocturnal hunters
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*The best-known representative is P. nigriventer, the Brazilian Wandering Spider
*The best-known representative is P. nigriventer, the Brazilian Wandering Spider


==Venom==
===Venom===
*A complex mixture of polypeptide components. Neurotoxicity is the most clinically relevant.
*A complex mixture of polypeptide components. Neurotoxicity is the most clinically relevant.
*Histamine and other components potentiate localized swelling and vascular permeability
*Histamine and other components potentiate localized swelling and vascular permeability
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*Initial intense pain that radiates to the trunk
*Initial intense pain that radiates to the trunk
*Within 10-20 minutes, onset of systemic toxicity
*Within 10-20 minutes, onset of systemic toxicity
**Tachycardia
**[[Tachycardia]]
**Hypertension
**[[Hypertension]]
**Profuse diaphoresis,
**Profuse diaphoresis,
**Salivation
**Salivation
**Vertigo
**[[Vertigo]]
**Vision disturbances
**[[Visual disturbances]]
**Nausea and Vomiting
**[[Nausea and vomiting]]
**Priapism
**[[Priapism]]
*Death has been reported, particularly in children and frail adults, from respiratory paralysis
*Death has been reported, particularly in children and frail adults, from respiratory paralysis
*Most recover in 24-48hours
*Most recover in 24-48hours
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==Management==
==Management==
*Largely Supportive Care
*Largely Supportive Care
**Pain Control
**[[Pain Control]]
***Local anesthetic infiltration at site of the bite is effective in 95% of cases
***[[Local anesthetic]] infiltration at site of the bite is effective in 95% of cases
***Opiates are discouraged as they may potentiate respiratory depression in severe envenomation
***[[Opioids]] are discouraged as they may potentiate respiratory depression in severe envenomation
*Antivenom
*Antivenom
**Polyvalent and Monovalent formulations available
**Polyvalent and Monovalent formulations available
***Skin testing and antihistamine ppx recommended prior to use
***Skin testing and antihistamine prophylaxis recommended prior to use
***1-5 vials given IV or IM
***1-5 vials given IV or IM
**Clinical response judged by relief of pain or resolution of priapism
**Clinical response judged by relief of pain or resolution of priapism
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==See Also==
==See Also==
*[[Envenomations, bites and stings]]
*[[Envenomations, bites and stings]]
==External Links==


==References==
==References==
<references/>
<references/>
[[Category:Environmental]]
[[Category:Dermatology]]

Latest revision as of 13:08, 29 May 2022

Background[1]

Phoneutria nigreventer, The Brazilian Wandering Spider
  • Identification: Brown gray with white spots forming a longitudinal band on the dorsal abdomen and a red-brown brush of hair on the chelicerae. Large in size (4.5-6cm) with 4-5mm fangs.
    • They do not form webs, but rather are mobile nocturnal hunters
    • among the largest and most aggressive spiders in South AmericaHabitat restricted to South America, largely Brazil, Argentina, and Uruguay.
  • Genus: Phoneutria
  • The best-known representative is P. nigriventer, the Brazilian Wandering Spider

Venom

  • A complex mixture of polypeptide components. Neurotoxicity is the most clinically relevant.
  • Histamine and other components potentiate localized swelling and vascular permeability
  • Several neurotoxic components that activate sodium channels, potentiating action potentials and causing uncontrolled muscle contractions.

Clinical Features

Differential Diagnosis

Envenomations, bites and stings

Evaluation

  • Generally a clinical diagnosis

Management

  • Largely Supportive Care
    • Pain Control
      • Local anesthetic infiltration at site of the bite is effective in 95% of cases
      • Opioids are discouraged as they may potentiate respiratory depression in severe envenomation
  • Antivenom
    • Polyvalent and Monovalent formulations available
      • Skin testing and antihistamine prophylaxis recommended prior to use
      • 1-5 vials given IV or IM
    • Clinical response judged by relief of pain or resolution of priapism

Disposition

  • May discharge those with no systemic symptoms after period of ED observation
  • Admit patients with signs or symptoms of systemic toxicity

See Also

References

  1. Leslie V. Boyer, Greta J. Binford, Janice A. Degan. Spider Bites. Paul S. Auerbach. In: Auerbach’s Wilderness Medicine. 7th Ed. 2017: 1010-1011.