Irukandji
Irukandji syndrome is produced by a small amount of
venom and induces excruciating muscle
cramps in the arms and legs, severe pain in the back and kidneys, a burning sensation of the skin and face, headaches, nausea, restlessness, sweating, vomiting, an increase in heart rate and blood pressure, and psychological phenomena such as the feeling of impending doom.
[19]The syndrome is in part caused by release of
catecholamines.
[12] The venom contains a
sodium channel modulator.
[12]
The sting is moderately irritating; the severe syndrome is delayed for 5–120 minutes (30 minutes on average). The symptoms last from hours to weeks, and victims usually require hospitalisation. Contrary to belief, researchers from James Cook University and Cairns hospital in far north Queensland have found that vinegar promotes the discharge of jellyfish venom. "You can increase the venom load in your victim by 50 per cent," says Associate Professor Jamie Seymour from the Australian Institute of Tropical Health and Medicine at the university. "That's a big amount, and that's enough to make the difference, we think, between someone surviving and somebody dying."
[20] However, other research indicates that while vinegar may increase the discharge from triggered stingers, it also prevents untriggered stingers from discharging; since the majority of stingers do not trigger immediately, the Australian Resuscitation Council continues to recommend using vinegar.
[21]
Treatment is symptomatic, with
antihistamines and anti-hypertensive drugs used to control inflammation and
hypertension; intravenous
opioids, such as
morphine and
fentanyl, are used to control the pain.
[20] Magnesium sulfate has been used to reduce pain and hypertension in Irukandji syndrome,
[22] although it has had no effect in other cases.
[23]
Irukandji jellyfish are usually found near the coast, attracted by the warmer water, but blooms have been seen as far as five kilometres offshore. When properly treated, a single sting is normally not fatal, but two people in Australia are believed to have died from Irukandji stings in 2002 during a rash of incidents on Australia's northern coast attributed to these jellyfish
[3][24][25][26]—greatly increasing public awareness of Irukandji syndrome. It is unknown how many other deaths from Irukandji syndrome have been wrongly attributed to other causes. It is also unknown which jellyfish species can cause Irukandji syndrome apart from Carukia barnesi and Malo kingi.
[27]