Box jellyfish

Background

Box jellyfish

Nematocyst stages of discharge

• cnidarian invertebrates distinguished by their cube-shaped medusae
• "Chironex fleckeri" cause of most deaths
• largely restricted to the Indo-Pacific Ocean/Australian waters but various species can be found widely
• most stings are benign (local treatment only), only a few species have been implicated in human deaths

Mechanism

• specific venom components unclear
• thought to affect sodium/potassium/calcium channels
• Chironex fleckeri venom causes cell membranes to become porous allowing K+ influx/hyperkalemia

Clinical Features

• stings associated with immediate pain, lasting up to 8 hours, and linear welts in a cross-hatched pattern
  • may progress to blisters/necrosis
• 25-30% may still have tentacles attached
• systemic envenomation (usually >10% BSA) can manifest as cardiac arrhythmias, respiratory dysfunction, death
  • usually manifests within 5 minutes of sting
• delayed hypersensitivity reactions occur in >50%
  • itching, redness at sting sites 7-14d after initial incidence

Differential Diagnosis

Marine toxins and envenomations

• Toxins
  • Scombroid
  • Ciguatera
  • Neurotoxic shellfish poisoning
  • Paralytic shellfish poisoning
  • Tetrodotoxin (e.g. pufferfish)
• Stingers
  • Stingray injury
• Venomous fish (catfish, zebrafish, scorpion fish, stonefish)
  • Lionfish
  • Sea urchins
  • Cone shells
• Nematocysts
  • Jellyfish (Cnidaria)
    • Box jellyfish
  • Portuguese man-of-war
  • Coral reef
  • Fire Corals
  • Sea anemones
  • Sea wasps
• Bites
  • Octopus

Evaluation

• Generally a clinical diagnosis

Management

• pain control
• pour liberal amounts of vinegar and remove any tentacles
  • tentacles separated from medusae can still emit venom
• supportive measures for minor envenomations (ice recommended but heat may actually work better)
• antihistamines and steroids for hypersensitivity reaction
• do NOT pressure bandage
• antivenom for life-threatening envenomations
  • ovine IgG Fab with 20,000 units/ampule

Antivenom Indications^

• cardiac arrest
  • undiluted antivenom administered as an IV Push: up to 6 vials
  • if no response then give magnesium IV
• hypotension, tachycardia, shock, arrhythmia
  • dilute 3 amps antivenom in 100mL NS and run over 20 minutes
  • can repeat for a total of 6 vials
• intractable pain
  • give 1 amp diluted in 100mL NS run over 20 minutes

^anti-venom can cause serum sickness 4-14 days after administration

See Also

• Marine toxins and envenomations

References

1. Bastian Bentlage, Paulyn Cartwright, Angel A. Yanagihara, Cheryl Lewis, Gemma S. Richards and Allen G. Collins.Evolution of box jellyfishes (Cnidaria: Cubozoa), a group of highly toxic invertebrates. Proceedings of the Royal Society, November 18, 2009 DOI:10.1098/rspb.2009.1707
2. Currie BJ, Jacups SP. Prospective study of Chironex fleckeri and other box jellyfish stings in the “Top End” of Australia’s Northern Territory. Med J Aust 2005; 183: 631-636
3. Hughes RJ, Angus JA, Winkel KD, Wright CE. A pharmacological investigation of the venom extract of the Australian box jellyfish, Chironex fleckeri, in cardiac and vascular tissues. Toxicol Lett. 2012 Feb 25;209(1):11-20. Epub 2011 Dec 2.
4. http://www.toxinology.com/generic_static_files/cslavh_antivenom_boxjelly.html

Authors

Ann Huang, Ross Donaldson