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  1. Cnidarians (Jellyfish, Corals and Anemones)
  2. Clinical Management

Clinical Management

This is relevant for all animals belonging to Cnidarians (Jellyfish, Corals and Anemones).

Guidance when the culprit has not been seen / not identified 

In most cases of jellyfish encounters, the culprit has not been seen at all, has only been seen vaguely or has not been reliably identified.

The 'clinical management' section you accessed provides guidance in such cases.

Consult

Which jellyfish are dangerous?

The jellyfish which are responsible for the majority of life-threatening envenoming and fatal outcome are

A wide range of jellyfish is relatively harmless with the exception of life-threatening immediate-type hypersensitivity reactions in sensitized individuals. It seems to be rare, however (see below; see Tibballs et al. 2011, Togias et al. 1985). 

See 'Various other jellyfishes causing stings in humans'.

There is, however, a multitide of species for which reliable data are missing, both epidemiological and clinical, which could cause significant including life-threaenting envenoming. 

It can be difficult or even impossible to distinguish between anaphylactic shock and toxin-related cardiopulmonary failure. 

E.g., apart from Caraukia barnesi, other carybdeid jellyfish may cause Irukandji syndrome (Gershwin et al 2013: “Table 1.2 Summary of ecology and syndrome characteristics of species known or believed to cause Irukandji syndrome”; Tibballs et al 2012; Debate: Little et al 2006, Gershwin 2006, Fenner 2006): Alatina mordens, Carukia shinju, Carybdea alata, Carybdea rastonii, Carybdea xaymacana, Malo maxima, Malo kingi, Alatina mordens, Gerongia rifkinae, and Morbakka fenneri.

Cnidarian venoms are (thermo-)labile. At body temperature they lose their activity. Thus, a patient may still be rescued with sustained resuscitation efforts.

Prevention: Avoidance of further stings has been suggested. If complete avoidance is found an unacceptable restriction, 'stinger suits' and carrying adrenaline for self-injection may be an option (Stein et al. 1989).

Seasonal, local 'epidemics' of jellyfish occur; e.g. Pelagia noctiluca (see below) in the Mediterranean Sea affects thousands of bathers affected each year. Stings are at the beginning very painful which can persist for several days. Signs and symptoms can recur several times for weeks after the inital sting.

Clinical Features

Local effects

Well documented in all venomous jellyfish: e.g., Aurelia sp., Carukia barnesi, Carybdea sp., Chironex fleckeri, Chiropsalmus quadrigatus, Chrysaora sp., Cyanea sp., Gonionemus sp., Linuche sp., "Morbakka" (Tamoya virulenta?), Pelagia sp., Physalia sp., Rhizostoma sp., Stomolophus sp., Tamoya sp. and other cnidarians; very severe in Chironex sp. envenoming with ladder-like "cross-hatching" pattern, Physalia sp. with linear, whip-like pattern, whereas in Carukia sp. envenomig skin lesion can be very difficult to identify or can be absent including pain.

  • Acute (within minutes), painful linear or blotchy urticarial or papulovesicular skin lesions, erythema (see 'morphological characteristics'). Necrosis, ulceration at a later stage,
  • acute regional vascular insufficiency distal to the sting (extremities),
  • ocular involvement with  pain, conjunctivitis, corneal oedema, iridocyclitis.
  • Delayed or recurrent skin lesions1: pruritic, onset 4–30 days after the sting, duration of each episode 1–7 days, several episodes possible. 

Autonomous and neuromuscular nervous sytem effects 

Well documented in Carukia sp. envenoming: the so called 'Irukanji syndrome'. Systemic signs may be delayed for many hours.
Clinical features of the syndrome resemble those of an adrenal medullary or catecholamine excess, such as seen in cases of phaeochromocytoma. 

  • Cramping abdominal pain, back pain, limb pain, 
  • vomiting, 
  • state of anxiety, 
  • cardiac arrhythmias, 
  • arterial hypertension, 
  • pulmonary oedema, 
  • heart failure 

Cardiac effects

Well documented in Chironex sp. envenoming.
Current understanding is that cardiac effects are the main cause of systemic envenoming. However, there may also be neurotoxic effects involved. The mechanism of action of the venom components that may cause neurological effects is unclear.

  • Cardiac arrhythmias, 
  • arterial hypertension, 
  • respiratory insufficiency,
  • cardiopulmonary failure within minutes possible

Haematological effects

Haemolytic anaemia (rarely reported in Physalia sp. envenoming)

Muscular effects

Rhadomyolysis (possibly in Physalia sp. envenoming)

1Delayed and recurrent skin lesions

There are numerous case reports and some studies on delayed and recurrent skin lesions following jellyfish stings (Auerbach and Hays 1987, Burnett and Calton 1985, Burnett et al. 1987a, Letot et al. 1990, Mansson et al. 1985, Matusow 1980, Ohtaki et al. 1986, 1990, O'Reilly et al 2001, Piérard et al. 1990, Reed et al. 1984). For review see Tibballs et al. (2011).
Recurrent skin symptoms following jellyfish stings can present a differential diagnostic problem, in particular if they appear after a long delay and if the patient does not remember the sting or the doctor failed to enquire about it.
With regard to aetiology, it is assumed that this is a type IV hypersensitivity reaction. Two different histological forms have been observed:

  • Contact dermatitis-like skin reactions (Ohtaki et al. 1990),
  • skin reactions of a granulomatous nature (Reed et al. 1984).

Auerbach and Hays (1987) observed erythema nodosum with arthralgia and fever following a Physalia physalis sting.

See Tibballs (2026) and Tibballs et al (2011).

Is it likely that the patient had an accident due to a venomous jellyfish?

Inquire

  • time of the sting
  • local, possibly regional pain
  • muscle pain, in particular back pain.

Assess

  • state of consciousness

Measure

  • blood pressure/pulse
  • respiratory rate
  • oxygen saturation (pulse oximeter)

Observe/investigate

  • the sting itself ("prints", which may enable differentiation of the cause - see above),.
  • extent of the sting (important for the distinction between "minor stings" and "major stings" in Chironex sp. envenoming),
  • conjunctivitis, corneal lesions,
  • clinical signs of regional vascular insufficiency distal to a sting on the extremities,
  • respiratory insufficiency/respiratory failure,
  • clinical signs of shock (cardiogenic shock, anaphylactic shock).

General supportive emergency medical treatment  

   

A general understanding of emergency medicine is required, or can be found in emergency medicine guidelines, e.g. ABCDE approach, WHO-ICRC Basic Emergency Care.

Comprehensive ABCDE approach
ICRC Basic Emergency Care: approach to the acutely ill and injured (SAMPLE and ABCDE approach: first module)

Supportive treatment is life-saving

Cardiocascular failure 

  • Cardiovascular management

ABCDE-approch is lifesaving as supportive treatment until the antivenom (Chironex fleckeri antivenom) applied acts (efficacy debated; see below: 'For which jellyfish envenoming is antivenom available?') or when antivenom (Chironex fleckeri antivenom) is not available or fails. 

Respiratory failure

  • Airway management
  • Breathing: Oxygen ⇨ assisted ventilation ⇨ mechanical ventilation

ABCDE-approch is life-saving as supportive treatment.

IMPORTANT
Cnidarian venoms are (thermo-)labile. It is assumed that they lose their activity within 15–20 min after absorption into the tissue or the blood circulation. Thus even if pharmacological /antivenom treatment fail, treatment success may still be possible if there are optimal resuscitation conditions. The patient's condition may deteriorate again after a temporary improvement of the circulatory condition due to renewed mobilisation of venom from the periphery (Williamson et al. 1984b).

For deailed advice of the jellyfish which are responsible for the majority of life-threatening envenoming and fatal outcome

Consult

and 

Wound management

  • Tetanus prophylaxis
  • Standard wound care (WHO 2010) 
  • Standard treatment of eye injury

For which jellyfish envenoming is antivenom available?

Chironex fleckeri BOX JELLYFISH ANTIVENOM, Australia 

Antivenom indications

See Product information

Complications

See Product information

See Antivenom treatment

Efficacy
The efficacy is debated (e.g., Winter et al 2009, Andreosso et al 2014, Piontek et al 2020).
Experience from treatment of individual cases:
Antivenom administration by trained ambulance personnel
The fact that antivenom works most likely best when given as soon as possible after the accident, led to considerations regarding how to administer antivenom as quickly as possible on the beach. Thus, ambulance personnel were trained to administer antivenom and have already used this knowledge a number of times. Reports on success are, however, only based on reports of few cases. (Beadnell et al. 1992, Fenner et al. 1989).

Research is ongoing to identify venom mechanisms of actions and effective venom antidotes (Lau et al 2019).