"Irukandji" syndrome: a risk for divers in tropical waters

MJA 1997; 167: 649  

To the Editor: Envenomation by the cubozoan jellyfish Carukia barnesi causes "Irukandji" syndrome (named by Dr Hugo Flecker after an Aboriginal tribe near Cairns).1 I report a case of Irukandji syndrome in a scuba diver for whom appropriate therapy was delayed because it was not initially considered as a possible cause of the patient's symptoms. A 28-year-old experienced diver was diving off Brampton Island in Queensland. During his second dive, at a depth of 6 m, he had a feeling of disequilibrium and so made a controlled ascent and removed his gear. His vague malaise was accompanied by aching pain in the groin and thighs, with numbness in the fingers and toes. This rapidly progressed to severe pain in the skin, muscles, face, jaw, testes and lumbar region, with profuse sweating and agitation. By the time he presented to the emergency department (after a delay of six hours because of transport difficulties), he was in great pain, with tachycardia (90 beats/min) and hypertension (170/100 mmHg). He was treated with 100% oxygen and pethidine (intramuscular and intravenous). At this stage, there were no diagnostic clues, except that symptoms had developed rapidly within minutes of his ascent. Decompression sickness was therefore considered, but after two conversations with the consultant at the Townsville General Hospital Hyperbaric Unit, an interview with the dive buddy, and in view of the patient's diving experience and the dive history, this diagnosis was dismissed. Irukandji syndrome was suggested and, when prompted, the patient recalled seeing a small jellyfish while descending and feeling a slight irritation on his right arm. A 3 cm x 4 cm oval inflamed area was evident on his right antecubital fossa and the patient provided a sketch of the jellyfish (Figure). He was commenced on an intravenous morphine infusion over 10 hours. Although a dull chest pain and lower-limb pain persisted, he did not require further analgesia. His serum creatine phosphokinase level peaked at 7317 IU/L (normal range, 10-60 IU/L) and his serum lactate dehydrogenase level reached 349 IU/L (normal range, 120-300 IU/L). Echocardiography after two days showed mild mitral valve regurgitation. Fortunately, the patient escaped the more sinister complications of Carukia envenomation (myocardial failure and pulmonary oedema).2-4 This is the first reported case where a patient with Irukandji syndrome identified the jellyfish. It has been reported that the syndrome may be mistaken for decompression sickness,5,6 thus evading rapid diagnosis and triggering costly evacuation and recompression procedures (J Williamson, Director of Hyperbaric Medicine, Royal Adelaide Hospital, personal communication). This case is a reminder that Irukandji syndrome can be a "diving-related illness", and should always be considered in the differential diagnoses of an ill diver in tropical waters. John C Hadok Senior Medical Officer, Emergency Department, Mackay Base Hospital PO Box 5580, Mackay, QLD 4740 E-mail: jchadokAThealth.qld.gov.au Fenner PJ, Williamson J, Callanan VI, Anderley I. Further understanding of, and a new treatment for, "Irukandji" (Carukia barnesi) stings. Med J Aust 1986; 145: 569-574. Fenner PJ, Williamson JA, Burnett JW, et al. The "Irukandji syndrome" and acute pulmonary oedema. Med J Aust 1988; 149: 150-156. Martin JC, Audley I. Cardiac failure following Irukandji envenomation. Med J Aust 1990; 153: 164-166. Herceg I. Pulmonary oedema following an Irukandji sting. SPUMS J (South Pacific Underwater Medicine Society Journal) 1987; 17: 95-97. Williamson J. Scuba diving perspective. In: Williamson JA, Fenner PJ, Burnett JW, Rifkin JF, editors. Venomous and poisonous marine animals. Sydney: University of New South Wales Press, 1996: 423-427. Williamson J. "Irukandji" syndrome or decompression sickness or cerebral arterial gas embolism? A differential diagnostic trap for practitioners of diving medicine in north Queensland. SPUMS J 1985; 15: 38-39. My thanks to Drs Bruce Todd, Bert Sadleir and Associate Professor John Williamson.