Difference between revisions of "Spider bites"

(Review Questions)
(I added general history, evaluation, and treatment of undifferentiated spider bites)
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==Differential Diagnosis==
 
==Differential Diagnosis==
 
{{Bites and stings DDX}}
 
{{Bites and stings DDX}}
 +
 +
==History==
 +
* Determine circumstances of bite to assess consistency with spider habitat and behavior   
 +
** Indoors vs outdoors
 +
** Day vs night 
 +
** Geographic location (recent travel)
 +
* Appearance of the spider if seen
 +
* Dead spiders can be preserved in 70% EtOH and later identified by arachnologists or entomologist
 +
 +
==Clinically important spider genera by geographic region==
 +
* North America 
 +
** Loxosceles
 +
** Latrodectus
 +
** Tegenaria
 +
* South America
 +
** Loxosceles
 +
** Latrodectus
 +
** Phoneutria
 +
* Africa
 +
** Loxosceles
 +
** Latrodectus
 +
* Europe
 +
** Loxosceles
 +
** Latrodectus
 +
* Australia
 +
** Atrax
 +
** Hadronyche
 +
** Latrodectus 
 +
* Asia
 +
** Latrodectus
 +
 +
==Physical Exam==
 +
* No pathognomonic signs proving lesion is a spider bite
 +
* Assess both bite site and for systemic signs
 +
* Bite Site
 +
** Location
 +
*** Spider bites more common when clothing is tight against skin
 +
** Number of bites
 +
*** Multiple bites suggest parasitic insect and not spider
 +
** Appearance of bite
 +
*** Erythema, pallor, hemorrhage, induration, tenderness, paresthesia, vesicles
 +
* Systemic findings
 +
** Abnormal vital signs
 +
** Altered mental status
 +
** Abdominal pain
 +
** Diaphoresis
 +
** Generalized rash
 +
** Muscle fasciculations, spasm, or tenderness
 +
 +
==Treatment==
 +
* Clean area of bite
 +
* Tetanus prophylaxis
 +
* Analgesics
 +
* Hydration
 +
* Surgical follow up if indicated for debridement of necrotic area 
 +
* Antivenom is indicated only for specific envenomation
 +
* No proven benefit for corticosteroids
 +
* No indication for antibiotics unless concern for cellulitis
  
 
==See Also==
 
==See Also==
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==References==
 
==References==
 
<references/>
 
<references/>
 +
* Boyer LV, Binford GJ, Degan JA. Spider Bites. In Auerbach PS, Cushing TA, Harris NS. Auerbach’s Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017: 993-1016.
  
 
[[Category:Environmental]]
 
[[Category:Environmental]]
 
[[Category:Toxicology]]
 
[[Category:Toxicology]]

Revision as of 15:50, 22 March 2019

Types

Differential Diagnosis

Envenomations, bites and stings

History

  • Determine circumstances of bite to assess consistency with spider habitat and behavior
    • Indoors vs outdoors
    • Day vs night
    • Geographic location (recent travel)
  • Appearance of the spider if seen
  • Dead spiders can be preserved in 70% EtOH and later identified by arachnologists or entomologist

Clinically important spider genera by geographic region

  • North America
    • Loxosceles
    • Latrodectus
    • Tegenaria
  • South America
    • Loxosceles
    • Latrodectus
    • Phoneutria
  • Africa
    • Loxosceles
    • Latrodectus
  • Europe
    • Loxosceles
    • Latrodectus
  • Australia
    • Atrax
    • Hadronyche
    • Latrodectus
  • Asia
    • Latrodectus

Physical Exam

  • No pathognomonic signs proving lesion is a spider bite
  • Assess both bite site and for systemic signs
  • Bite Site
    • Location
      • Spider bites more common when clothing is tight against skin
    • Number of bites
      • Multiple bites suggest parasitic insect and not spider
    • Appearance of bite
      • Erythema, pallor, hemorrhage, induration, tenderness, paresthesia, vesicles
  • Systemic findings
    • Abnormal vital signs
    • Altered mental status
    • Abdominal pain
    • Diaphoresis
    • Generalized rash
    • Muscle fasciculations, spasm, or tenderness

Treatment

  • Clean area of bite
  • Tetanus prophylaxis
  • Analgesics
  • Hydration
  • Surgical follow up if indicated for debridement of necrotic area
  • Antivenom is indicated only for specific envenomation
  • No proven benefit for corticosteroids
  • No indication for antibiotics unless concern for cellulitis

See Also

References

  • Boyer LV, Binford GJ, Degan JA. Spider Bites. In Auerbach PS, Cushing TA, Harris NS. Auerbach’s Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017: 993-1016.