Snake Envenomation

Snake Envenomation is a topic covered in the 5-Minute Emergency Consult.

To view the entire topic, please or purchase a subscription.

Emergency Central is a collection of disease, drug, and test information including 5-Minute Emergency Medicine Consult, Davis’s Drug, McGraw-Hill Medical’s Diagnosaurus®, Pocket Guide to Diagnostic Tests, and MEDLINE Journals created for emergency medicine professionals. Explore these free sample topics:

Emergency Central

-- The first section of this topic is shown below --



  • Pit viper venom:
    • Mixture of proteolytic enzymes and thrombin-like esterases:
      • Enzymes cause local muscle and subcutaneous tissue necrosis.
      • Esterases have defibrinating anticoagulant effect, leading to venom-induced consumption coagulopathy (VICC) in severe envenomations.
  • Bite location:
    • Extremity bites most common
    • Head, neck, or trunk bites more severe than bite on extremities
  • Severe envenomation:
    • Direct bite into artery or vein
    • Neurotoxic envenomations
  • Bite mark significance:
    • Pit viper bite: Classically includes 1 or 2 puncture marks
    • Nonvenomous snakes and elapids: Horseshoe-shaped row of multiple teeth marks
  • 25% of all pit viper bites are dry and do not result in envenomation.


Venomous Snakes Indigenous to US
  • Pit vipers (Crotalinae):
    • Account for 95% of all envenomations
    • Rattlesnakes, cottonmouths, and copperheads
  • Coral snakes (Elapidae):
    • Neurotoxic
    • Western coral snakes, found in Arizona and New Mexico
    • More venomous eastern coral snakes, found in Carolinas and Gulf states

International Exotic Venomous Snakes
Occur in zoos or in owners of exotic snakes
Pediatric Considerations
  • 30% of all snakebites involve patients younger than 20 yr. 12% of all snakebites are 9 yr or younger.
  • Because of their low body weight, smaller children and infants are more vulnerable to severe envenomation with systemic symptoms.

-- To view the remaining sections of this topic, please or purchase a subscription --