View source for Box jellyfish envenomation

==Background==
[[File:Avispa marina cropped.png|thumb|Box jellyfish]]
[[File:Nematocyst discharge.png|thumb|Nematocyst stages of discharge]]
*Cnidarian invertebrates distinguished by their cube-shaped medusae
*''Chironex fleckeri'' or [[sea wasp]] is cause of most deaths
*Largely restricted to the Indo-Pacific Ocean/Australian waters but various species can be found widely
*83% occur in < 1m of water.
*Most stings are benign (requiring local treatment only), recent data suggests fatality rate is much lower than the 20% previously reported. 
**Morbidity and Mortality are dose- and time-dependent, which explains why majority of deaths have been children.  

===Mechanism<ref>Hauglid, Christopher, DO, et al. “EMERGEN-SEA MEDICINE: An Overview of Sea Urchins, Coral, Starfish, and More.” ACEP Now, vol. 40, no. 7, 2021, pp. 8–9.</ref>===
*Has about 15 tentacles (measure up to 3m in length) that contain millions of "stinging cells" called nematocysts. 
*Contact with the tentacles cause rapid onset of pruritic/burning 
*Thought to affect sodium/potassium/calcium channels
*Rhabodmyolysis can occur from sustained muscle contractions caused by myotoxins in venom. 
*Cardiovascular collapse can occur d/t dysrhythmia (from hyperkalemia) and osmotic dysregulation of endothelial and cardiac tissues from pore-forming toxins within the venom. 
*''[[Sea wasp|Chironex fleckeri]]'' venom causes cell membranes to become porous allowing K+ influx/hyperkalemia

==Clinical Features==
[[File:PMC4756446 13104 2016 1931 Fig4 HTML.png|thumb|Patient stung by multiple box jellyfish tentacles.]]
[[File:PMC4756446 13104 2016 1931 Fig1 HTML.png|thumb|Patient stung by multiple box jellyfish tentacles.]]
[[File:PMC4756446 13104 2016 1931 Fig3 HTML.png|thumb|Box jellyfish sting.]]
[[File:PMC4756446 13104 2016 1931 Fig2 HTML.png|thumb|Pediatric box jellyfish sting.]]
*Stings associated with immediate pain, lasting up to 8 hours, and linear welts in a cross-hatched "ladder-rung" pattern
**Erythematous maculopapular rash
**May progress to blisters/necrosis
*25-30% may still have tentacles attached
*Systemic envenomation (usually >10% [[BSA]]) can manifest as cardiac [[arrhythmias]], [[respiratory distress|respiratory dysfunction]], death
**Usually manifests within 5 minutes of sting
*Delayed [[hypersensitivity reaction]]s occur in >50%
**[[Pruritus|Itching]], redness at sting sites 7-14d after initial incidence

==Differential Diagnosis==
{{Marine envenomation DDX}}

==Evaluation==
*Generally a clinical diagnosis

==Management==
*First remove any tentacles
**tentacles separated from medusae can still emit venom
*4-5% acetic acid/vinegar solution should be applied to the injured area for at least 30 seconds.<ref>Hauglid, C., Kiel, J., &amp; Schmidt, A. (2021, April 23). Emergen-Sea Medicine: Overview of Marine Envenomations - Page 4 of 5. ACEP Now. https://www.acepnow.com/article/emergen-sea-medicine-overview-of-marine-envenomations/4/. </ref>
*[[analgesia|Pain control]]
*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
**Bovine IgG Fab with 20,000 units/ampule
*'''Avoid treating with fresh water, alcohol, methylated spirits, or urine as these have shown to increase nematocyst firing.''' <ref>Hauglid, Christopher, DO, et al. “EMERGEN-SEA MEDICINE: An Overview of Sea Urchins, Coral, Starfish, and More.” ACEP Now, vol. 40, no. 7, 2021, pp. 8–9.</ref>

===Antivenom Indications^===
*[[Cardiac arrest]]
**undiluted antivenom administered as an IV Push: up to 6 vials
**if no response then give [[magnesium]] IV (0.2mmol/kg, max 10mmol in adults)
*[[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''

==Disposition==

==See Also==
*[[Marine toxins and envenomations]]
*[[Sea wasp sting]]

==References==
#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
#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
#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.
#http://www.toxinology.com/generic_static_files/cslavh_antivenom_boxjelly.html

[[Category:Environmental]][[Category:Toxicology]]