Irukandji Syndrome (Carukia barnesi)
Clinical presentation and course
- The initial sting is usually not felt and there is a short delay to the onset of systemic symptoms. Local signs, such as welts or dermal markings, are minimal or absent
- Multiple systemic symptoms develop from 30–120 minutes after contact with the jellyfish. These include a sense of impending doom, agitation, dysphoria, vomiting, generalised sweating and severe pain in the back, limbs or abdomen. Hypertension and tachycardia are common.
- Symptoms usually settle within 12 hours
- Severe envenoming manifests within 4 hours with on‑going significant opioid requirements. These patients are at risk of toxic cardiomyopathy, cardiogenic shock and pulmonary oedema and may require intubation and mechanical ventilation
- Intracerebral haemorrhage occurred in two patients within 3–4hours of the sting, presumably due to uncontrolled hypertension.
- Apply generous volumes of vinegar to all visible sting sites to inactivate all undischarged nematocysts (sting cells)
- Do not apply a pressure immobilisation bandage (PIB)
- Transport all patients with pain refractory to first‑aid, or systemic symptoms to a medical facility – this is a potentially life‑threatening emergency
- Potential early life‑threats that require immediate interventions include:
- — Severe hypertension
- — Pulmonary oedema
- Administer IV fentanyl (0.5–1.0 microgram/kg/dose) repeated every 10 minutes until appropriate analgesia is achieved. Large doses may be required (e.g. 200–300 microgram). Note: If fentanyl is not available, give morphine 0.1 mg/kg IV in titrated doses
- Treat nausea with IV promethazine (25 mg; 0.5 mg/kg in children)
- Control hypertension refractory to opioid analgesia with an intravenous infusion of glyceryl trinitrate (50 mg in 100 mL starting at 6 mL/minute; 1–4 microgram/kg/minute in children) titrated to achieve a systolic blood pressure <160 mmHg
- Manage pain refractory to opioids with IV magnesium (0.2 mmol/kg up to 10 mmol in adults) administered over 5–15 minutes. Seek expert advice
- None available.
- Envenoming by the box jellyfish (Chironex fleckeri) is associated with immediate pain and obvious dermal markings (large welts). Tentacles may be seen adherent to the skin
- Bluebottle stings (Physalia species) are associated with immediate pain and dermal markings. The pain usually resolves within 1 hour and systemic symptoms are extremely rare
- Decompression illness may lead to generalised pain or collapse shortly after a diver has surfaced. Welts are not seen
- Redback spider envenoming (Latrodectus hasseltii) causes bite site pain and sweating, followed by more generalised pain, sweating and dysphoria. It is associated with contact with a spider on land.
- Clinical features of envenoming occur after the patient has left the water, so they may be unaware they have been stung
- Irukandji syndrome should be considered in any patient presenting with clinical features during or shortly after swimming in tropical coastal Australian waters
- Clinical features of dysphoria, severe generalised pain, sweating, hypertension and pulmonary oedema, in the absence of major dermal findings, is pathognomic of irukandji syndrome
- Patient controlled analgesia may be useful where there is an on‑going opioid requirement.
- The role of magnesium. Anecdotal evidence suggests that IV magnesium (in the same infusion doses as used in preeclampsia) may have a role in treatment of severe irukandji syndrome.
- The role of benzodiazepines in the management of symptoms presumed due to catecholamine release
- The agent of choice to manage hypertension and tachycardia.
Related Links and References:
- Toxicology Conundrum 008
- Toxicology Conundrum 009
- Nickson CP, Waugh EB, Jacups S, Currie B. Irukandji syndrome case series from Australia’s tropical Northern Territory. Ann Emerg Med. 2009 Sep;54(3):395-403. Epub 2009 May 5. PMID: 19409658 [fulltext pdf].
- Jack Barnes and the Irukandji Enigma
- Irukandji in moving pictures