Sea wasp sting

Background

Box jellyfish (Chironex fleckeri)

Nematocyst stages of discharge

• Chironex fleckeri, commonly known as sea wasp
• Large form of box jellyfish, found mostly off the coast of northern Australia to the Philippines
• Extremely deadly, often considered one of the most poisonous jellyfish
• Identification: Often difficult to distinguish in environment, as animal is transparent. Pale blue bell, often the size of a basketball, with 15 tentacles emerging from lower corners up to 3 meters in length. Has been described as having an eerie similarity to a human skull
• Tentacles contain millions of stinging cells known as cnidocytes

Clinical Features

• Sting is extremely painful, described as burning, and can cause death as quickly as 3-5 minutes
• Can cause significant hypotension, hypertension, cardiac arrhythmia, and cardiac arrest
• Most stings are mild and are self-limiting
• Deaths most commonly occur in children
• Venom causes cells to become porous and leaky, causing hyperkalemia

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

• Assess/manage ABCs
• ECG (look for arrhythmia, blocks, ischemia)
• CXR
• CBC, BMP, troponin/CK
• Consider:
  • ABG, echo, nematocyst sampling

Management

• Address ABCs (e.g. CPR, fluid resuscitation, vasopressors, intubation as needed)
• Remove tentacles!!!
  • Nematocysts can continuing firing and delivering more venom if tentacles still attached
  • If available, pour lots of vinegar over tentacles first to inactivate
• Do NOT apply pressure dressing/immobilization (triggers nematocysts to fire)
• Box Jellyfish antivenom, if available
  • Cardiac arrest: 6 ampules IV push
  • Systemic envenomation with hypotension, collapse, or significant arrhythmia: 3 ampules in 100mL NS over 20m
  • Pain refractory to opioids: 1 ampule in 100mL NS over 20m
• Magnesium sulfate: 10 mmol (~2-3g) IV if hemodynamically unstable

See Also

• Marine toxins and envenomations
• Box jellyfish

References

https://lifeinthefastlane.com/toxicology-conundrum-010/