Studies

Australia
Little and Mulcahy 1998: Retrospective chart review of patients (n=62) who had at least two symptoms or signs of Irukandji envenomation as described by Flecker (1952) and Barnes (1964). The charts have been extracted from the databases of the only two emergency departments in 1996 in Cairns where all patients who are presenting are registered.

Case reports

Australia
Barnes 1964: 6 jellyfish stings. Identification: 'print' of the jellyfish body, clinical picture 3/6; self-stinging experiments 3/6.
Fenner et al. 1986a: 2 jellyfish stings. Identification: 'print' of the jellyfish body, clinical picture.
Fenner et al. 1986b: 3 jellyfish stings. Identification: 'print' of the jellyfish body, clinical picture.
Fenner et al. 1988: 3 jellyfish stings. Identification: 'print' of the jellyfish body, clinical picture; retrospectively via antibody detection with ELISA (1/3).

Fenner and Hadok 2002: 1 jellyfish sting. Identification: clinical picture ("Irukandji syndrome").
Martin and Audley 1990: 1 jellyfish sting. Identification: typical 'print' of the jellyfish body, clinical picture.

Signs & symptoms

Local effects

Minimal local erythema, possibly transient small blisters, localised sweating, local pain may be so mild that the victim does not initially notice the sting or underestimates it (Barnes 1964, Fenner et al. 1986a, 1986b, 1988, Flecker 1952, Martin and Audley 1990, Southcott 1952) (Fig. 4.11).

Systemic effects

57/62 developed sytemic signs and/or symptoms: 25/62 abdominal cramps, 31/62 hypertension, 24/62 back pain, 24/62 nausea and vomiting, 21/62 limb cramps, 16/62 chest tightness, 15/62 marked distress, 2/62 pulmonary oedema (Little and Mulcahy 1998).

Many of the signs and symptoms of the Irukandji syndrome are reminiscent of the consequences of a massive catecholamine release, such as occurs with a phaeochromocytoma. Plasma catecholamine levels and measurement of catecholamine metabolites in the urine of patients would provide information regarding the aetiology of Irukandji syndrome, but to date there are none available. The pathogenesis of the pulmonary oedema is attributed to both cardiogenic and non-cardiogenic factors (Fenner et al. 1988, Martin and Audley 1990).

Signs and symptoms appearing with a delay of approximately 30 minutes (5-40 minutes) after the sting (Fenner 2000): cramping abdominal pain, back pain, limb pain (nature of the pain: in waves, pain gradually increasing to a maximum that lasts up to 15 min, after a break, the cycle re-commences); vomiting; tachycardia, cardiac arrhythmias, arterial hypotension (diastolic 130–140 mmHg), pulmonary oedema, headache, piloerection, peripheral cyanosis (peripheral vasoconstriction), oliguria (decreased blood supply to the kidneys), fear of death. These symptoms of envenoming can persist for up to 24 h or more (Barnes 1964, Fenner et al. 1986a, 1986b, 1988, Flecker 1952, Martin and Audley 1990, Southcott 1952).

"Irukandji-like" syndromes are said to occur after stings from "Morbakka" (Tamoya  virulenta?), Tamoya sp., Gonionemus oshoro and Stomolophus sp. and possibly other species.

Morbidity

Discharged from hospital within 6 hours of envenomation with minimal or no symptoms (28/62). Admitted to hospital 35/62. Admitted to high-dependenc care (2/62) (Little and Mulcahy 1998).

Case fatality rate

1 death published (Fenner and Hadok 2002, however, identification of culprit on the basis of clinical picture only ("Irukandji syndrome").

Laboratory and physical investigations

1. Echocardiography

Globally reduced contractility of the left ventricle (18 h after the sting) (Martin and Audley 1990). Moderate dilation of all 4 chambers and moderately severe diffuse hypokinesia (57 h after the sting). Normal echocardiogram at the check-up on the 24th day (Fenner et al. 1988). Reduced left ventricular function (2/2) (Little and Mulcahy 1998).

2. Intracardiac pressure measurement (Swan-Ganz catheter)

Left ventricular filling pressure increased, but not to the extent expected from the clinical status (Fenner et al. 1988).

3. Chest X-ray
Pulmonary oedema (15 h after the sting) (Fenner et al. 1988).

4. ELISA

Within a few days after the sting, specific IgG antibodies are formed that persist for many months. The species of jellyfish that caused the sting can be identified retrospectively using antibody detection with an ELISA test. However, there are problems with specificity (Burnett et al. 1988a).

First aid

Inactivation of nematocysts remaining on the skin: household vinegar 4–6(–10)% is poured over the affected areas of skin (Hartwig et al. 1980). In areas where Carukia barnesi occurs it is also recommended to treat unremarkable stings in this way, as Carukia stings appear harmless at first, but can nonetheless cause severe systemic signs of envenoming after a period of time. Putting fresh water on the stung area of skin or rubbing it lead to a massive release of venom (Fenner et al. 1988, Martin and Audley 1990).

Treatment (symptomatic)

Note: The evdence base for treating  "Irukandji syndrome" is anecdotal. It was developed in Australia and employed for the treatment of a number of patients (Bailey et al 2003, Fenner and Hadok 2002, Fenner et al. 1986a, 1986b, 1988, Little and Mulcahy 1998, Martin and Audley 1990).

1. Pain

Pethidine 50 mg i.v. (bolus), followed by an infusion of pethidine (30 mg/h) or bolus morphine 5 mg i.v., followed by 2.5 mg every 5 min as needed. It is necessary to make provision for the treatment of adverse reactions (respiratory depression) (Fenner et al. 1988).

Opiates 38/62: pethidine 30/38, morphine 2/38, morphine and pethidine 6/38. Of the adults (n=24) received  ≥100mg 16/24 with 1/24 receiving 750 mg over 10 hours (Little and Mulcahy 1998).

Note: There are theoretical reasons to avoid pethidine (Bailey et al 2003, Little and Mulcahy 1998).

2. Anxiety
Diazepam (Fenner et al. 1986b).

3.  Arterial hypertension
- Phentolamine 5 mg i.v. initially, followed by repeated doses of 10 mg i.v., until the blood pressure is controlled (Fenner et al. 1988),
- phentolamine 1–2 mg i.v. initially, followed by an infusion of 5 mg/h (Martin and Audley 1990).

Note: Phentolamine has been used, but may not be available in emergency departments. An agent with a shorter half-life may be preferable (glyceryl trinitrate) given the potential for cardiovascular collapse. Caution should be exercised to avoid life-threatening hypotension as cases of echocardiographically proven cardiac dysfuncton have occured (Bailey et al 2003).

4.  Pulmonary oedema

Pulmonary oedema is treated in the usual manner (Bailey et al 2003).

In the usual manner with a loop diuretic (furosemide) i.v., morphine i.v. and sublingual nitrate. However, it must be remembered that there may be a poor response (see above, Neurological effects). In that case endotracheal intubation and artificial respiration (IPPV) will be necessary (Fenner et al. 1988).

Treatment (specific)

Antivenom: not available.