In the United States, 98% of venomous snakebites―also known as envenomation―are from the North American pit viper and have been reported in all states, with the exception of Hawaii1-3:
North American pit viper envenomations progress over time. Outcomes vary from patient to patient, depending on many variables, including timeliness of treatment.6
Envenomation can affect 3 critical—and potentially life- or limb-threatening—areas6:
North American pit viper venom contains a complex mixture of toxins that often includes6-8*:
Each toxin may have distinct actions on diverse body systems, and different toxins may work synergistically to increase toxicity.6-8
After envenomation, a depot of venom often remains at the site of the bite, which may prolong the clinical effects of the venom.8
1. Gummin DD, Mowry JB, Spyker DA, Brooks DE, Fraser MO, Banner W. 2016 Annual Report of the American Association of Poison Control Centers National Poison Data System (NPDS): 34th Annual Report. Clin Toxicol. 2017;55(10):1072-1252. 2. Gold BS, Barish RA, Dart RC. North American snake envenomation: diagnosis, treatment, and management. Emerg Med Clin N Am. 2004;22(2):423-443. 3. Seifert SA, Boyer LV, Benson BE, Rogers JJ. AAPCC database characterization of native U.S. venomous snake exposures, 2001-2005. Clin Toxicol. 2009;47(4):327-335. 4. Frequently Asked Questions. Department of Wildlife Ecology and Conservation website. Ufwildlife.ifas.ufl.edu/venomous_snake_faqs.shtml. Accessed May 23, 2018. 5. Spiller HA, Bosse GM, Ryan ML. Use of antivenom for snakebites reported to United States poison centers. Am J Emerg Med. 2010;28(7):780-785. 6. Lavonas EJ, Ruha A-M, Banner W, et al. Unified treatment algorithm for the management of crotaline snakebite in the United States: results of an evidence-informed consensus workshop. BMC Emerg Med. 2011;11:2. 7. Rattlesnake Envenomation. EMed website. www.emed.ie/Trauma/Environmental/Snakebite.php. Accessed May 23, 2018. 8. Smith J, Bush S. Envenomations by reptiles in the United States. In: Mackessy SP, ed. Handbook of Venoms and Toxins of Reptiles. Boca Raton, FL: CRC Press; 2010:475-488.