Nematocysts: Difference between revisions

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==Clinical Features==
==Clinical Features==
[[File:PMC3760923 abd-88-0496-g04.png|thumb|Skin lesion after contact with the cubomedusa Chiropsalmus quadrumanus jellyfish]]
*Isolated stinging, pain
*Isolated stinging, pain
*Severe
*Severe

Revision as of 15:22, 16 November 2019

Background

  • Jellyfish; box jellyfish is most deadly
  • Most toxic: Australia and other Indo-Pacific waters


Mechanism

Nematocyst stages of discharge
  • Physical contact or osmotic gradient causes discharge of nematocysts
  • A spring loaded venom delivery system
  • Once opened, a nematocyst releases all of its contained venom

Clinical Features

Skin lesion after contact with the cubomedusa Chiropsalmus quadrumanus jellyfish

Irukandji syndrome

Differential Diagnosis

Marine toxins, envenomations, and bites

Evaluation

  • Generally a clinical diagnosis

Management

  • Remove tentacles and nematocysts
  • Hot salt water immersion (inactivates heat labile toxins), submerging the area in 45 ℃ water for 20 minutes has been shown to provide significant pain relief[1]
  • Consider topical lidocaine
  • Consider oral or parenteral analgesia for severe pain
  • Acetic Acid may inhibit or trigger nematocyst discharge and thereby increase or decrease pain depending on species (can use fruit juice or other flavored sodas if vinegar not available)
  • Symptomatic treatment for Irukandji syndrome
  • Antivenom is available for severe box jellyfish sting

Avoid

  • Urine, ethanol, ammonia
  • Fresh or tap water (causes nematocyst discharge via the osmotic gradient)

Disposition

See Also

References

  1. Ward NT, Darracq MA, Tomaszewski C, et al. Evidence based treatment of jellyfish stings in North America and Hawaii. Ann Emerg Med. 2012;60(4):339-414.
  2. Cegolon L, Heymann WC, Lange JH, et al. Jellyfish stings and their management: a review. Mar Drugs. 2013;11(2): 523-50
  1. #Isbister GK, Currie BJ. Hot water immersion v icepacks for treating pain of Chironex fleckeri stings: a randomised controlled trial. Med J Aust. 2017 Oct 16;207(8):362. PubMed PMID: 29020913.