Octopus bite

Background

• Blue-ringed octopus (genus Hapalochlaena) is commonly cited venomous octopus
  • Venom contains tetrodotoxin, which inhibits voltage-gated Na⁺ channels --> paralysis
  • Potentially lethal
  • Becomes bright yellow with blue rings when provoked

Blue ringed octopus

Clinical Features

• Local erythema
• Paresthesias
• Flaccid paralysis
• Respiratory failure

Differential Diagnosis

Marine toxins, envenomations, and bites

• Toxins
  • Ciguatera
  • Scombroid
  • Tetrodotoxin (e.g. pufferfish)
  • Shellfish poisoning
    • Amnesic shellfish poisoning
    • Diarrheal shellfish poisoning
    • Neurotoxic shellfish poisoning
    • Paralytic shellfish poisoning
• Stingers
  • Stingray injury
• Venomous fish
  • Cone shells
  • Lionfish
  • Sea urchins
  • Stonefish
  • Other: Catfish, zebrafish, scorpion fish
• Nematocysts
  • Coral reef
  • Fire coral
  • Jellyfish (Cnidaria)
    • Box jellyfish
    • Sea wasp
  • Portuguese man-of-war
  • Sea anemones
  • Seabather's eruption
• Phylum porifera (sponges)
• Bites
  • Alligator and crocodile attacks
  • Octopus bite
  • Shark bite
• Infections
  • Vibrio species in saltwater
  • Aeromonas species in freshwater

Evaluation

• Clinical diagnosis

Management

• Supportive treatment only; no antivenom exists

See Also

• Marine toxins and envenomations