Stonefish envenomation

Background

Stonefish

• Synanceia genus of fish of the family Synanceiidae
• Found in the coastal regions of the Indo-Pacific.
• This is a grey fish which possesses multiple venomous spines.
• The venom remains stable for up to 48 hours after the fish has died.
• This is the most venomous fish known, with venom likened to that of a cobra.
  • The venom blocks cardiac calcium channels, increases systemic catecholamine release, simultaneously causing diffuse vasodilation and increased tissue destruction which propogates uptake of its own venom.

Clinical Features

Extensive erythema, gross swelling up to the entire index finger, dorsum, and distal third forearm from stonefish envenomation.

• Local erythema, ecchymosis, swelling, necrosis
• Intense, sharp pain that peaks at 60 minutes but can lasts for days.
• Systemic toxicity:
  • Hypotension, tachycardia, arrhythmia, syncope, vomiting, compartment syndrome, and pulmonary edema (cardiogenic)
• Death can occur in as few as 6 hours.

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 shell
  • Lionfish
  • Sea urchins
  • Crown-of-Thorns Starfish
  • Stonefish
  • Other: Catfish, zebrafish, scorpion fish
• Nematocysts
  • Coral reef
  • Fire coral
  • Jellyfish (Cnidaria)
    • Box jellyfish
      • Irukandji syndrome
    • 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

Workup

• No specific testing available

Diagnosis

• Clinical diagnosis

Management

• Pain management and venom neutralization is accomplished via hot-water (45 C) immersion for 30-60 minutes
• Clean wound, update tetanus, remove retained tissue
• One fifth of wounds develop local infection, but prophylactic antibiotics remain controversial
• High risk for Vibrio vulnificus which can lead to necrotizing fasciitis.
• Antivenom includes Commonweatlth Serum Laboratories stonefish antivenom.
  • All doses are intramuscular d/t risk of anaphylactoid reaction.
  • Give 1 vial for 1-2 puncture wounds, 2 vials for 3-4 wounds, etc.
  • 1 vial is equivalent to 2,000 units and neutralizes 20mg of venom

Disposition

• Patients should be observed for 6-12 hours.

See Also

• Marine toxins and envenomations