Elapidae (Coral Snakes)

Background

  • All coral snakes are brightly colored with black, red, and yellow rings
  • Red and yellow rings touch in coral snakes, but are separated in nonpoisonous mimics
    • "Red touch yellow, kills a fellow; red touch black, venom lack"
    • This tool for identifying coral snakes does not apply to Mexican species
Coral snake.
  • Venom: mainly neurotoxic (irreversibly binds to acetylcholine receptors)

Clinical Features

  • Local injury is often minimal and easy to miss as venom is delivered via chewing rather than injection
  • Venom effects may develop hours after a bite

Serious complications

Differential Diagnosis

Envenomations, bites and stings

Evaluation

  • CBC with diff
  • DIC labs: PT/PTT/INR, fibrinogen, fibrin degradation products, d-dimer
  • BMP
  • LFTs
  • CK

Management

Local Care

  • Do:
    • Immobilize limb in a neutral position
    • Remove all jewelry
    • Mark the leading edge of erythema/edema
  • Do not:
    • Attempt to suck out the venom
    • Place the affected part in cold water
    • Use a tourniquet or wrap
    • Antivenom is first line treatment for compartment syndrome; fasciotomy is last resort if elevated pressures persist.

Antivenom

  • Give 3-5 vials of Antivenin (Micrurus fulvius) to ALL patients who have definitely been bitten
    • It may not be possible to prevent further effects or reverse effects once they develop
    • Additional doses of antivenom are reserved for cases in which symptoms/signs appear
  • Prepare for allergic reaction from equine produced Antivenin (may dilute solution, or administer with epinephrine/benadryl)

Monitor for respiratory failure

Disposition

  • Admit all patients (even if initially symptom free)

See Also

References

  1. http://www.emdocs.net/management-of-venomous-snake-bites-in-north-america/
  2. Isbister GK. Snakebite does not cause disseminated intravascular coagulation: coagulopathy and thrombotic microangiopathy in snake envenoming. Semin Thromb Hemost. 2010 Jun;36(4):444-51.
  3. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/elapidae