Difference between revisions of "Spider bites"

(Created page with "==Brown Recluse== ===Clinical Features=== #Bite is initially painless #Mild reaction ##Most common ##Mild erythematous lesion that later becomes firm and heals without scar #Seve...")
 
(Physical Exam)
 
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==Brown Recluse==
+
==Types==
===Clinical Features===
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*[[Brown recluse spider bite]]
#Bite is initially painless
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*[[Black widow spider bite]]
#Mild reaction
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*[[Tarantula spider bite]]
##Most common
 
##Mild erythematous lesion that later becomes firm and heals without scar
 
#Severe reaction
 
##Begins w/ mild-severe pain several hrs after bite accompanied by erythema and swelling
 
##Hemorrhagic blister then forms surrounded by vasoconstriction-induced blanched skin
 
##By day 3 or 4 hemorrhagic area may become ecchymotic
 
###Leads to "red, white, and blue" sign (erythema, blanching, ecchymosis)
 
##By end of first week ecchymotic area may become necrotic w/ eschar formation
 
#Systemic effects
 
##Rare
 
##Occur predominantly in children 24-72hr after the bite
 
###Include nausea/vomiting, fever, arthralgias, thrombocytopenia, rhabdo, renal failure
 
===Treatment===
 
#Local wound care
 
#Abx are indicated only if signs of infection exist; secondary infections are uncommon
 
  
==Black Widow==
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<gallery mode="packed">
===Clinical Features===
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File:Tarantula640px-Brachypelma smithi 2009 G03.jpg|[[Tarantula]]
#Local
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File:Western Black Widow (Latrodectus hesperus).jpg|[[Black widow spider]]
##Pinprick sensation; then increasing local pain that may spread to entire extremity
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File:Brown Recluse.jpg|[[Brown recluse]]
##Erythema appears 20-60 min after the bite
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</gallery>
##Pain begins to abate after several hours and disappears by 2-3d
 
#Systemic
 
##Muscle cramp-like spasms in large muscle groups (although exam rarely reveals rigidity)
 
##Pain becomes generalized
 
###Severe abdominal wall musculature pain and cramping is well described
 
##Headache, nausea/vomiting, diaphoresis, photophobia, dyspnea
 
##A-fib, myocarditis, priapism, and death are rare
 
  
===Treatment===
+
==Differential Diagnosis==
#Pain and muscle spasms
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{{Bites and stings DDX}}
##Opiods and benzos
 
#Systemic illness
 
##Antivenom
 
###Consider for:
 
####Children
 
####Pregnant women
 
####Elderly
 
  
===Disposition===
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==History==  
#Consider admission for:
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* Determine circumstances of bite to assess consistency with spider habitat and behavior   
##Symptoms of moderate envenomation
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** Indoors vs outdoors
##Pregnant women
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** Day vs night 
##Children
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** Geographic location (recent travel)
##Pts w/ preexisting cardiovascular disease or HTN
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* Appearance of the spider if seen
 +
* Dead spiders can be preserved in 70% EtOH and later identified by arachnologists or entomologist
  
==Tarantulas==
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==Clinically important spider genera by geographic region==  
===Clinical Features===
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* North America 
#Abdominal hairs may be flicked a short distance when threatened
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** Loxosceles
##Rarely penetrate human skin but can imbed deeply into conjunctiva and cornea
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** Latrodectus
#Bites can be painful but systemic symptoms other than fever are unusual
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** Tegenaria
 +
* South America
 +
** Loxosceles
 +
** Latrodectus
 +
** Phoneutria
 +
* Africa
 +
** Loxosceles
 +
** Latrodectus
 +
* Europe
 +
** Loxosceles
 +
** Latrodectus
 +
* Australia
 +
** Atrax
 +
** Hadronyche
 +
** Latrodectus 
 +
* Asia
 +
** Latrodectus
  
===Management===
+
==Physical Exam==
#Red eye and pain after handling a tarantula necessitates an ocular exam
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* No pathognomonic signs proving lesion is a spider bite
##Hairs may be difficult to detect on slit lamp
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* Assess both bite site and for systemic signs
#Treatment is surgical removal of hairs and topical steroids
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* 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 ([[tachycardia]] possible with black widow)
 +
** [[Altered mental status]]
 +
** [[Abdominal pain]]
 +
** Diaphoresis
 +
** Generalized [[rash]]
 +
** Muscle fasciculations, spasm, or tenderness
 +
 
 +
==Treatment==
 +
* Clean area of bite
 +
* [[Tetanus prophylaxis]]
 +
* [[analgesia|Analgesics]]
 +
* Hydration
 +
* Surgical follow up if indicated for debridement of necrotic area 
 +
* [[Antivenin]] is indicated only for specific envenomation
 +
* No proven benefit for [[corticosteroids]]
 +
* No indication for antibiotics unless concern for [[cellulitis]]
  
 
==See Also==
 
==See Also==
[[Bites and Stings]]
+
*[[Bites and Stings]]
  
==Source==
+
==References==
*Tintinalli
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<references/>
*Rosen's
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* 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:Environ]]
+
[[Category:Environmental]]
 +
[[Category:Toxicology]]

Latest revision as of 21:59, 28 September 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

Treatment

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.