Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Rattlesnake Envenomation

  • Author: Sean P Bush, MD, FACEP; Chief Editor: Joe Alcock, MD, MS  more...
 
Updated: Jun 25, 2015
 

Background

Rattlesnakes are pit vipers and include the genera Crotalus and Sistrurus. Pit vipers may be identified by a heat-sensing pit anteroinferior to the eye. Rattlesnakes may be identified in all but one species by a rattle at the tip of the tail. Rattlesnakes are indigenous from North America to South America. See the image below.

Juvenile southern Pacific rattlesnake (Crotalus or Juvenile southern Pacific rattlesnake (Crotalus oreganus helleri). Photo by Sean Bush, MD.
Next

Pathophysiology

Venom is usually injected into subcutaneous tissue via hollow movable fangs located in the anterior mouth. Occasionally, intramuscular or (probably rarely) intravenous injection occurs. Rattlesnake venom is generally composed of several digestive enzymes and spreading factors, which result in local and systemic injury.

Clinically, local effects most commonly predominate, progressing from pain and edema to ecchymosis and bullae. Hematologic abnormalities, including defibrination with or without thrombocytopenia, may result, but serious bleeding is uncommon. Local or diffuse myotoxicity may result in complications such as compartment syndrome or rhabdomyolysis. Other general effects include shock, myokymia/fasciculations, taste changes, and vomiting. Rarely, direct cardiotoxicity or allergy to venom may occur. Some rattlesnakes may exhibit neurotoxicity with minimal local tissue effects (see Mojave Rattlesnake Envenomation).

Previous
Next

Epidemiology

Frequency

United States

Approximately 7,000-8,000 reptile bites are reported to the American Association of Poison Control Centers (AAPCC) each year.[1, 2] However, this figure is probably conservative because of underreporting. Rattlesnakes cause the majority of all bites by identified venomous snakes in the United States.[3] Dry bite (ie, no clinical evidence of envenomation) occurs in between 10 and 50% of strikes.

International

An estimated 300,000-400,000 venomous snakebites occur per year. Although rattlesnakes are not found naturally outside of North America, Central America, and South America, they are imported into zoos, museums, and private collections in other regions of the world.

Sex

Males are bitten more commonly than females.

Age

Young adults are bitten most commonly.

Previous
 
 
Contributor Information and Disclosures
Author

Sean P Bush, MD, FACEP Professor of Emergency Medicine, The Brody School of Medicine at East Carolina University

Sean P Bush, MD, FACEP is a member of the following medical societies: American College of Emergency Physicians, International Society on Toxicology, Society for Academic Emergency Medicine, Wilderness Medical Society

Disclosure: Received honoraria from BTG Inc. for speaking and teaching.

Specialty Editor Board

John T VanDeVoort, PharmD Regional Director of Pharmacy, Sacred Heart and St Joseph's Hospitals

John T VanDeVoort, PharmD is a member of the following medical societies: American Society of Health-System Pharmacists

Disclosure: Nothing to disclose.

James Steven Walker, DO, MS Clinical Professor of Surgery, Department of Surgery, University of Oklahoma College of Medicine

James Steven Walker, DO, MS is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Osteopathic Emergency Physicians, American Osteopathic Association

Disclosure: Nothing to disclose.

Chief Editor

Joe Alcock, MD, MS Associate Professor, Department of Emergency Medicine, University of New Mexico Health Sciences Center

Joe Alcock, MD, MS is a member of the following medical societies: American Academy of Emergency Medicine

Disclosure: Nothing to disclose.

Additional Contributors

Robert L Norris, MD Professor, Department of Emergency Medicine, Stanford University Medical Center

Robert L Norris, MD is a member of the following medical societies: American College of Emergency Physicians, Society for Academic Emergency Medicine, International Society of Toxinology, American Medical Association, California Medical Association, Wilderness Medical Society

Disclosure: Nothing to disclose.

References
  1. Watson WA, Litovitz TL, Klein-Schwartz W, Rodgers GC Jr, Youniss J, Reid N, et al. 2003 annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. Am J Emerg Med. 2004 Sep. 22(5):335-404. [Medline].

  2. Bronstein AC, Spyker DA, Cantilena LR Jr, Green J, Rumack BH, Heard SE. 2006 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS). Clin Toxicol (Phila). 2007 Dec. 45(8):815-917. [Medline].

  3. Wingert WA, Chan L. Rattlesnake bites in southern California and rationale for recommended treatment. West J Med. 1988 Jan. 148(1):37-44. [Medline].

  4. Norris RL Jr. Snake Venom Poisoning in the United States: Assessment and Management. Emerg Med Rep. 1995. 16:87-94.

  5. Norris Jr RL, Bush SP. North American venomous reptile bites. Auerbach PS, ed. Wilderness Medicine. 5th ed. 2006.

  6. Bush SP, Jansen PW. Severe rattlesnake envenomation with anaphylaxis and rhabdomyolysis. Ann Emerg Med. 1995 Jun. 25(6):845-8. [Medline].

  7. Bond RG, Burkhart KK. Thrombocytopenia following timber rattlesnake envenomation. Ann Emerg Med. 1997 Jul. 30(1):40-4. [Medline].

  8. Hurlbut KM, Dart RC, et al. Reliability of clinical presentation for predicting significant pit viper envenomation. Ann Emerg Med. 1988. 438-9.

  9. Bogdan GM, Dart RC. Prolonged and recurrent coagulopathy after North American pit viper envenomation (abstract). Ann Emerg Med. 1996. 27:820.

  10. Boyer LV, Seifert SA, Clark RF, McNally JT, Williams SR, Nordt SP, et al. Recurrent and persistent coagulopathy following pit viper envenomation. Arch Intern Med. 1999 Apr 12. 159(7):706-10. [Medline].

  11. Burgess JL, Dart RC. Snake venom coagulopathy: use and abuse of blood products in the treatment of pit viper envenomation. Ann Emerg Med. 1991 Jul. 20(7):795-801. [Medline].

  12. Riffer E, Curry SC, Gerkin R. Successful treatment with antivenin of marked thrombocytopenia without significant coagulopathy following rattlesnake bite. Ann Emerg Med. 1987 Nov. 16(11):1297-9. [Medline].

  13. Carroll RR, Hall EL, Kitchens CS. Canebrake rattlesnake envenomation. Ann Emerg Med. 1997 Jul. 30(1):45-8. [Medline].

  14. French WJ, Hayes WK, Bush SP, Cardwell MD, Bader JO, Rael ED. Mojave toxin in venom of Crotalus helleri (Southern Pacific Rattlesnake): molecular and geographic characterization. Toxicon. 2004 Dec 1. 44(7):781-91. [Medline].

  15. Bush SP. Snakebite suction devices don't remove venom: they just suck. Ann Emerg Med. 2004 Feb. 43(2):187-8. [Medline].

  16. Bush SP, Hegewald KG, Green SM, Cardwell MD, Hayes WK. Effects of a negative pressure venom extraction device (Extractor) on local tissue injury after artificial rattlesnake envenomation in a porcine model. Wilderness Environ Med. 2000 Fall. 11(3):180-8. [Medline].

  17. Bush SP, Green SM, Laack TA, Hayes WK, Cardwell MD, Tanen DA. Pressure immobilization delays mortality and increases intracompartmental pressure after artificial intramuscular rattlesnake envenomation in a porcine model. Ann Emerg Med. 2004 Dec. 44(6):599-604. [Medline].

  18. Hardy DL, Bush SP. Pressure/immobilization as first aid for venomous snakebite in the United States. Herpetol Rev. 1998. 29:204-8.

  19. Consroe P, Egen NB, Russell FE, Gerrish K, Smith DC, Sidki A, et al. Comparison of a new ovine antigen binding fragment (Fab) antivenin for United States Crotalidae with the commercial antivenin for protection against venom-induced lethality in mice. Am J Trop Med Hyg. 1995 Nov. 53(5):507-10. [Medline].

  20. Bush SP, Wu VH, Corbett SW. Rattlesnake venom-induced thrombocytopenia response to Antivenin (Crotalidae) Polyvalent: a case series. Acad Emerg Med. 2000 Feb. 7(2):181-5. [Medline].

  21. Bush SP, Green SM, Moynihan JA, Hayes WK, Cardwell MD. Crotalidae polyvalent immune Fab (ovine) antivenom is efficacious for envenomations by Southern Pacific rattlesnakes (Crotalus helleri). Ann Emerg Med. 2002 Dec. 40(6):619-24. [Medline].

  22. Dart RC, Seifert SA, Carroll L, Clark RF, Hall E, Boyer-Hassen LV, et al. Affinity-purified, mixed monospecific crotalid antivenom ovine Fab for the treatment of crotalid venom poisoning. Ann Emerg Med. 1997 Jul. 30(1):33-9. [Medline].

  23. Jurkovich GJ, Luterman A, McCullar K, Ramenofsky ML, Curreri PW. Complications of Crotalidae antivenin therapy. J Trauma. 1988 Jul. 28(7):1032-7. [Medline].

  24. Offerman SR, Bush SP, Moynihan JA, Clark RF. Crotaline Fab antivenom for the treatment of children with rattlesnake envenomation. Pediatrics. 2002 Nov. 110(5):968-71. [Medline].

  25. Premawardhena AP, de Silva CE, Fonseka MM, Gunatilake SB, de Silva HJ. Low dose subcutaneous adrenaline to prevent acute adverse reactions to antivenom serum in people bitten by snakes: randomised, placebo controlled trial. BMJ. 1999 Apr 17. 318(7190):1041-3. [Medline].

  26. Clark RF, Selden BS, Furbee B. The incidence of wound infection following crotalid envenomation. J Emerg Med. 1993 Sep-Oct. 11(5):583-6. [Medline].

  27. Guisto JA. Severe toxicity from crotalid envenomation after early resolution of symptoms. Ann Emerg Med. 1995 Sep. 26(3):387-9. [Medline].

  28. Langley RL, Morrow WE. Deaths resulting from animal attacks in the United States. Wilderness Environ Med. 1997. 8:8-16.

 
Previous
Next
 
Juvenile southern Pacific rattlesnake (Crotalus oreganus helleri). Photo by Sean Bush, MD.
A recent study suggests that the Extractor (Sawyer Products) does not reduce swelling after rattlesnake envenomation and may be associated with skin necrosis beneath the suction cup. Photo by Sean Bush, MD.
Moderate rattlesnake envenomation in a toddler after treatment with antivenom. Photo by Sean Bush, MD.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.