Fatal envenomation by jellyfish causing Irukandji syndrome

To the Editor: Interpretation of the report describing the first death attributed to the Irukandji syndrome should be tempered by the fact that significant unstated assumptions have been made in attributing the cause of death to a jellyfish.1 While envenomation by a jellyfish remains the likely diagnostic possibility, no evidence is presented that unequivocally confirms a jellyfish as the lethal agent.

Several methods could have been used to support or confirm the diagnosis of jellyfish envenomation, including sampling of nematocysts from the victim's skin (before or after death), jellyfish capture, or reports of other similar, but less severe, stings from the same beach around the time the victim was stung.

In severe jellyfish envenomation, attempts are often made to harvest nematocysts from patients' skin, most commonly by skin scraping or by sticky tape sampling.2 Recovered nematocysts may help to identify the species, and confirm the diagnosis.3 Although successful nematocyst recovery is uncommon in Irukandji syndrome, it is disappointing that "no attempt was made to sample nematocysts"1 given the relative simplicity of the procedure and the importance of this case. The authors state that "no sting site was clearly delineated",1 but then go on to say that there were, in fact, areas of "skin flushing and intermittent diaphoresis"1 over a significant period of time. Sticky tape sampling of these areas may have yielded nematocysts, allowing positive species identification.

Postmortem skin sections have also been employed in Chironex fleckeri fatalities, and have shown nematocyst barbs on the victim's skin.4 Postmortem examination may also have revealed other contributing factors.

I am particularly interested in the assertion that almost every Irukandji syndrome patient in the Whitsundays develops a "rise in cardiac troponin levels".1 In fact, the cited article makes no mention of troponin, simply stating that CK-MB (creatine kinase isoenzyme) levels "can be abnormal",5 and that "some severe cases [of Irukandji syndrome] may have a CK-MB [level] well above the normal range".5

Many aspects of the diagnosis and treatment of jellyfish envenoming remain controversial. Accurate reporting of unusual cases is thus of the utmost importance.