Rattlesnake Envenomation Clinical Presentation

Updated: Mar 14, 2023
  • Author: Sean P Bush, MD, FACEP; Chief Editor: Joe Alcock, MD, MS  more...
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All or none of the following may be present. Note that symptoms are subject to change, and this change can be very rapid or very insidious. In addition, severity is generally guided by the most severely affected parameter. [16, 18, 19, 20, 21] See the following:

  • Pain around the bite site

  • Swelling

  • Taste changes (eg, a metallic taste)

  • Difficulty breathing

  • Chest pain

  • Nausea, vomiting, or diarrhea

  • Hematemesis, hematochezia

  • Neurologic symptoms - Weakness, paresthesias

  • Syncope, near syncope



Complications of snake envenomation may include the following:

  • Bleeding, such as gastrointestinal or intracranial

  • Compartment syndrome

  • Necrosis with resulting tissue loss or loss of function

  • Rhabdomyolysis, myoglobinuric renal failure

  • Infection

  • Respiratory difficulty

  • Death (rare in the United States)

  • Antivenom-associated anaphylaxis  - Type I (immediate) hypersensitivity reaction, which may be life threatening; characterized by urticaria, airway swelling, wheezing, and shock

  • Antivenom-associated serum sickness - Type III (delayed) hypersensitivity reaction; characterized by fever, urticaria, lymphadenopathy, and arthritis and may occur 3 days to 3 weeks after antivenom