Objective: To determine the immediate and delayed effects of jellyfish stings, and correlate these with microscopic identification of jellyfish nematocysts.
Design: Prospective study of patients presenting with jellyfish stings.
Participants and setting: 40 people presenting with jellyfish stings to the emergency department of a teaching hospital in tropical Australia between 1 August 1999 and 31 July 2000.
Main outcome measures: Clinical diagnosis (sting by Chironex fleckeri, "Darwin carybdeid" or other jellyfish, or "Irukandji" syndrome); clinical severity; delayed hypersensitivity; and sticky-tape sampling and microscopic identification of nematocysts.
Results: Patients were aged 2-50 years, with eight aged under 15 years; 23 were male. Presentations were consistent with C. fleckeri sting in 28 cases, Darwin carybdeid sting in five, and Irukandji syndrome in four. Sticky-tape sampling was done in 39 patients and was positive for C. fleckeri nematocysts in 23 and for non-C. fleckeri nematocysts in six, with nematocysts not detected in 10 (including all four with Irukandji syndrome). All microscopically confirmed C. fleckeri stings had typical clinical presentations. None of the stings were life-threatening, and no antivenom was given. Delayed hypersensitivity reactions were seen in 11 of the 19 patients (58%) followed up after stings positive for C. fleckeri nematocysts.
Conclusions: Although most jellyfish stings presenting to Royal Darwin Hospital I were caused by C. fleckeri, severe envenomation was rare. There was a strong association between clinical features and sticky-tape identification of nematocysts. Delayed hypersensitivity was common after C. fleckeri stings.