Coral Snake Envenomation 

  • Author: Robert L Norris, MD; Chief Editor: Rick Kulkarni, MD   more...
 
Updated: Dec 12, 2011
 

Background

Approximately 40-50 species of venomous coral snakes exist in North America and South America, with the greatest variety from Mexico to northern South America. A number of African and Asian coral snake species also exist. All coral snakes belong to the family Elapidae; Micrurus fulvius (eastern coral snake) and Micrurus tener (Texas coral snake) are the most important species in the United States.

Another US coral snake is Micruroides euryxanthus (Sonoran or Arizona coral snake); this is a relatively innocuous snake, and no deaths have been attributed to its bite.

Coral snakes tend to be relatively shy creatures, and bites are uncommon. Coral snakes account for fewer than 1% of venomous snakebites in the United States. Most people bitten by coral snakes are handling them intentionally. Most bites occur in the spring or fall.

Next

Pathophysiology

The coral snake venom apparatus is composed of a pair of small, fixed, hollow fangs in the anterior aspect of the upper jaw through which the snake conducts venom via a chewing motion (see the image below). Unlike pit vipers, such as rattlesnakes, copperheads, and cottonmouths, which strike quickly, coral snakes must hang on for a brief period to achieve significant envenomation in humans.

Coral snake skull. Coral snake skull.

Coral snake venoms tend to have significant neurotoxicity, inducing neuromuscular dysfunction. They have little enzymatic activity or necrotic potential compared with most vipers and pit vipers. These venoms tend to be some of the most potent found in snakes, yet the venom yield per animal is less than that of most vipers or pit vipers. Because of the relatively primitive venom delivery apparatus, as many as 60% of those bitten by North American coral snakes are not envenomed.

Previous
Next

Epidemiology

Frequency

United States

Probably fewer than 20 bites per year (though 99 alleged bites were reported to the American Association of Poison Control Centers in 2004).[1]

International

No accurate information on international incidence is available.

Mortality/Morbidity

No deaths related to coral snake bites have been reported in the United States since coral snake antivenom became available. Before that time, the estimated case-fatality rate was 10%, and the cause of death was respiratory or cardiovascular failure. Patients who survive the bite may require respiratory support for up to a week and may suffer persistent weakness for weeks to months.

Previous
Proceed to Clinical Presentation
 
 
Contributor Information and Disclosures
Author

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

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

Disclosure: Nothing to disclose.

Specialty Editor Board

Edmond A Hooker II, MD, DrPH, FAAEM  Assistant Professor, Department of Emergency Medicine, University of Cincinnati College of Medicine; Associate Professor, Department of Health Services Administration, Xavier University

Edmond A Hooker II, MD, DrPH, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine, American Public Health Association, Society for Academic Emergency Medicine, and Southern Medical Association

Disclosure: Nothing to disclose.

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.

David Eitel, MD, MBA  Associate Professor, Department of Emergency Medicine, York Hospital; Physician Advisor for Case Management, Wellspan Health System, York

David Eitel, MD, MBA is a member of the following medical societies: American College of Emergency Physicians, American Society of Pediatric Nephrology, Society for Academic Emergency Medicine, and Society of Critical Care Medicine

Disclosure: Nothing to disclose.

John D Halamka, MD, MS  Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center

John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Chief Editor

Rick Kulkarni, MD  Attending Physician, Department of Emergency Medicine, Cambridge Health Alliance, Division of Emergency Medicine, Harvard Medical School

Rick Kulkarni, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine

Disclosure: WebMD Salary Employment

References

  1. Watson WA, Litovitz TL, Rodgers GC Jr, et al. 2004 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. Am J Emerg Med. Sep 2005;23(5):589-666. [Medline].

  2. Davidson TM, Eisner J. United States coral snakes. Wilderness Environ Med. 1996;1:38-45.

  3. German BT, Hack JB, Brewer K, et al. Pressure-immobilization bandages delay toxicity in a porcine model of eastern coral snake (Micrurus fulvius fulvius) envenomation. Ann Emerg Med. Jun 2005;45(6):603-8. [Medline].

  4. Gray S. Pressure immobilization of snakebite. Wilderness Environ Med. Spring 2003;14(1):70-1. [Medline].

  5. Kitchens CS, Van Mierop LH. Envenomation by the Eastern coral snake (Micrurus fulvius fulvius). A study of 39 victims. JAMA. Sep 25 1987;258(12):1615-8. [Medline].

  6. Norris RL, Bush SP. North American venomous reptile bites. In: Auerbach PS, ed. Wilderness Medicine. 4th ed. St. Louis: Mosby; 2001:896-926.

  7. Norris RL, Dart RC. Apparent coral snake envenomation in a patient without visible fang marks. Am J Emerg Med. Jul 1989;7(4):402-5. [Medline].

  8. Norris RL, Ngo J, Nolan K, et al. Physicians and lay people are unable to apply pressure immobilization properly in a simulated snakebite scenario. Wilderness Environ Med. 2005;16(1):16-21. [Medline].

  9. Parrish HM, Khan MS. Bites by coral snakes: report of 11 representative cases. Am J Med Sci. May 1967;253(5):561-8. [Medline].

  10. Simpson ID, Tanwar PD, Andrade C, et al. The Ebbinghaus retention curve: training does not increase the ability to apply pressure immobilisation in simulated snake bite--implications for snake bite first aid in the developing world. Trans R Soc Trop Med Hyg. May 2008;102(5):451-9. [Medline].

 
Previous
Next
 
Snake envenomations, coral. Comparison of the harmless Lampropeltis triangulum annulata(Mexican milksnake) (top) with Micrurus tener(Texas coral snake) (bottom). Photo by Charles Alfaro.
Coral snake skull.
The Australian pressure immobilization technique. This technique has been shown to be helpful in delaying systemic absorption of elapid venoms, but its use in cobra bites remains controversial. A broad pressure bandage is immediately wrapped, beginning distally (Media file 3), around as much of the extremity as possible (see Media files 4 and 5). No effort should be spent removing clothing prior to bandage application. The bandage is wrapped snugly, as for a severely sprained ligament. A splint (or sling when applied to the upper extremity) is then placed (see Media files 6 and 7), and the victim is carried from the scene. The victim should expend no effort in getting to definitive care. Pressure immobilization should remain in place until the victim has reached medical care. The doctor will decide when to remove the bandages. If venom has been injected, it will move into the bloodstream quickly once the bandages are removed. The doctor should leave the bandages and splint in position until appropriate antivenom is available. Used with permission from Commonwealth Serum Laboratories.
The Australian pressure immobilization technique. This technique has been shown to be helpful in delaying systemic absorption of elapid venoms, but its use in cobra bites remains controversial. A broad pressure bandage is immediately wrapped, beginning distally (Media file 3), around as much of the extremity as possible (see Media files 4 and 5). No effort should be spent removing clothing prior to bandage application. The bandage is wrapped snugly, as for a severely sprained ligament. A splint (or sling when applied to the upper extremity) is then placed (see Media files 6 and 7), and the victim is carried from the scene. The victim should expend no effort in getting to definitive care. Pressure immobilization should remain in place until the victim has reached medical care. The doctor will decide when to remove the bandages. If venom has been injected, it will move into the bloodstream quickly once the bandages are removed. The doctor should leave the bandages and splint in position until appropriate antivenom is available. Used with permission from Commonwealth Serum Laboratories.
The Australian pressure immobilization technique. This technique has been shown to be helpful in delaying systemic absorption of elapid venoms, but its use in cobra bites remains controversial. A broad pressure bandage is immediately wrapped, beginning distally (Media file 3), around as much of the extremity as possible (see Media files 4 and 5). No effort should be spent removing clothing prior to bandage application. The bandage is wrapped snugly, as for a severely sprained ligament. A splint (or sling when applied to the upper extremity) is then placed (see Media files 6 and 7), and the victim is carried from the scene. The victim should expend no effort in getting to definitive care. Pressure immobilization should remain in place until the victim has reached medical care. The doctor will decide when to remove the bandages. If venom has been injected, it will move into the bloodstream quickly once the bandages are removed. The doctor should leave the bandages and splint in position until appropriate antivenom is available. Used with permission from Commonwealth Serum Laboratories.
The Australian pressure immobilization technique. This technique has been shown to be helpful in delaying systemic absorption of elapid venoms, but its use in cobra bites remains controversial. A broad pressure bandage is immediately wrapped, beginning distally (Media file 3), around as much of the extremity as possible (see Media files 4 and 5). No effort should be spent removing clothing prior to bandage application. The bandage is wrapped snugly, as for a severely sprained ligament. A splint (or sling when applied to the upper extremity) is then placed (see Media files 6 and 7), and the victim is carried from the scene. The victim should expend no effort in getting to definitive care. Pressure immobilization should remain in place until the victim has reached medical care. The doctor will decide when to remove the bandages. If venom has been injected, it will move into the bloodstream quickly once the bandages are removed. The doctor should leave the bandages and splint in position until appropriate antivenom is available. Used with permission from Commonwealth Serum Laboratories.
The Australian pressure immobilization technique. This technique has been shown to be helpful in delaying systemic absorption of elapid venoms, but its use in cobra bites remains controversial. A broad pressure bandage is immediately wrapped, beginning distally (Media file 3), around as much of the extremity as possible (see Media files 4 and 5). No effort should be spent removing clothing prior to bandage application. The bandage is wrapped snugly, as for a severely sprained ligament. A splint (or sling when applied to the upper extremity) is then placed (see Media files 6 and 7), and the victim is carried from the scene. The victim should expend no effort in getting to definitive care. Pressure immobilization should remain in place until the victim has reached medical care. The doctor will decide when to remove the bandages. If venom has been injected, it will move into the bloodstream quickly once the bandages are removed. The doctor should leave the bandages and splint in position until appropriate antivenom is available. Used with permission from Commonwealth Serum Laboratories.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2012 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.