Cobra Envenomation Clinical Presentation

Updated: Aug 03, 2022
  • Author: Bobak Zonnoor , MD, MMM; Chief Editor: Joe Alcock, MD, MS  more...
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Physical Examination

Abnormal heart rate and hypotension can result from autonomic dysfunction. Respiratory distress may lead to respiratory failure due to muscular paralysis.

Patient may present with altered mental status, ptosis (often the earliest sign of systemic toxicity), mydriasis, and/or generalized weakness or paralysis. Bulbar muscular dysfunction may result in slurred speech and drooling.

With venom into the eye, acute inflammation is present with ocular congestion, edema of the conjunctiva and cornea, and a whitish discharge. Slip-lamp or fluorescein tests may show corneal erosions.

Around the bite site, soft tissue edema with surrounding blistering may be noted. Necrosis may result, usually appearing within 48 hours of the bite.

Necrosis from a cobra bite. Photo by Sherman Minto Necrosis from a cobra bite. Photo by Sherman Minton, MD.




Complications of cobra envenomation may include the following:

  • Respiratory failure/arrest

  • Cardiovascular collapse

  • Prolonged neuromuscular weakness

  • Tissue necrosis, potentially resulting in limb loss / amputation

  • Venom-induced ophthalmia (spitting cobras)

  • Anaphylaxis, non-allergic anaphylactoid reaction, delayed  serum sickness (if and after antivenom administration)