Irukandji syndrome

Irukandji syndrome is a condition induced by envenomization through the sting of "Carukia barnesi", the Irukandji jellyfish, and other cubozoans.cite journal | author = Little M, P Pereira, T Carrette, J Seymour | title = Jellyfish Responsible for Irukandji Syndrome | journal = Q J Med | volume = 99 | issue = 6 | pages = 425–427 | year = 2006 | doi = 10.1093/qjmed/hcl057 | pmid = 16687419 ] It is seldom fatal, but is nevertheless one of the most painful experiences a human can endure. The condition was given its name in 1952 by Hugo Flecker, after the Aboriginal Irukandji people who live in Palm Cove, north of Cairns, where stings are common.cite journal | author = Flecker H | title = Irukandji sting to North Queensland bathers without production of weals but with severe general symptoms | journal = Med J Aust | volume = 2 | issue = 3 | pages = 89–91 | year = 1952 | pmid = 14956317]

Early experience

In 1964, Dr. Jack Barnes confirmed the cause of the syndrome to be due to a small box jelly, the Irukandji jellyfish ("Carukia barnesi"). In order to prove that the jellyfish was the cause of the syndrome, he captured one and deliberately stung himself, his son, and a local lifeguard, and observed the symptomscite journal | author = Barnes J | title = Cause and effect in Irukandji stingings | journal = Med J Aust | volume = 14 | issue = | pages = 897–904 | year = 1964 | pmid = 14172390] It is suspected that other Cubozoa can cause Irukandji syndrome,cite journal | author = Grady J, Burnett J | title = Irukandji-like syndrome in South Florida divers | journal = Ann Emerg Med | volume = 42 | issue = 6 | pages = 763–6 | year = 2003 | pmid = 14634600 | doi = 10.1016/S0196-0644(03)00513-4] but only seven jellyfish positively identified ("C. barnesi", "Alatina" cf. "mordens", "Carybdea alata", "Malo maxima", "Carybdea xaymacana", an as-yet unnamed ‘fire jelly’, and 1 other unnamed species).cite journal | author = Little M, Seymour J | title = Another cause of "Irukandji stingings" | journal = Med J Aust | volume = 179 | issue = 11–12 | pages = 654 | year = 2003 | pmid = 14636148]

Toxicity

When properly treated a single sting is normally not fatal; however, two people in Australia are believed to have died from Irukandji stingscite journal | author = Fenner P, Hadok J | title = Fatal envenomation by jellyfish causing Irukandji syndrome | journal = Med J Aust | volume = 177 | issue = 7 | pages = 362–3 | year = 2002 | pmid = 12358578] which has greatly increased public awareness of Irukandji syndrome. It is unknown how many other deaths from Irukandji syndrome have been wrongly attributed to other causes. The exact mechanism of action of Irukandji venom is unknown. It has been suggested that catecholamine excess may be an underlying mechanism in severe Irukandji syndrome.cite journal | author = Burnett J, Weinrich D, Williamson J, Fenner P, Lutz L, Bloom D | title = Autonomic neurotoxicity of jellyfish and marine animal venoms | journal = Clin Auton Res | volume = 8 | issue = 2 | pages = 125–30 | year = 1998 | pmid = 9613803 | doi = 10.1007/BF02267823] Animal studies appear to confirm a relationship between envenoming and an increase in circulating noradrenaline and adrenaline.cite journal | author = Tibballs J, Hawdon G, Winkel K | title = Mechanism of cardiac failure in Irukandji syndrome and first aid treatment for stings | journal = Anaesth Intensive Care | volume = 29 | issue = 5 | pages = 552 | year = 2001 | pmid = 11669442]

ymptoms

Most stings occur during the summer wet season in December-January. As the Jellyfish is very small, and as the venom is only injected through the tips of the nematocysts (the cnidocysts) rather than the entire lengths; the sting may barely be noticed at first. It has been described as feeling like little more than a mosquito bite. The symptoms, however, gradually become apparent and then more and more intense in the following 5 to 120 minutes (30 minutes on average). Irukandji syndrome includes an array of systemic symptoms including severe headache, backache, muscle pains, chest and abdominal pain, nausea and vomiting, sweating, anxiety, hypertension, and pulmonary edema.cite journal | author = Little M, Pereira P, Mulcahy R, Cullen P, Carrette T, Seymour J | title = Severe cardiac failure associated with presumed jellyfish sting. Irukandji syndrome? | journal = Anaesth Intensive Care | volume = 31 | issue = 6 | pages = 642–7 | year = 2003 | pmid = 14719425] Symptoms generally abate in 4 to 30 hours, but may take up to two weeks to resolve completely.

Treatment

Similarly to other box jellyfish, first aid consists of flushing the area with vinegar to neutralize the tentacle stinging apparatus. There is no antivenom; treatment is largely supportive, with analgesia being the mainstay of management. Antihistamines may be of benefit for pain relief,cite journal | author = Little M, Mulcahy R | title = A year's experience of Irukandji envenomation in far north Queensland | journal = Med J Aust | volume = 169 | issue = 11–12 | pages = 638–41 | year = 1998 | pmid = 9887916] but most cases require intravenous opioid analgesia. Fentanyl or morphine are usually chosen. Pethidine (aka meperidine in U.S. (Demerol)) should be avoided, as large doses are often required for pain relief and in this situation significant adverse effects from the pethidine metabolite norpethidine may occur.cite journal | author = Bailey P, Little M, Jelinek G, Wilce J | title = Jellyfish envenoming syndromes: unknown toxic mechanisms and unproven therapies | journal = Med J Aust | volume = 178 | issue = 1 | pages = 34–7 | year = 2003 | pmid = 12492389]

Magnesium sulfate has been proposed as a treatment for Irukandji syndrome after being apparently successfully used in one case.cite journal | author = Corkeron M | title = Magnesium infusion to treat Irukandji syndrome | journal = Med J Aust | volume = 178 | issue = 8 | pages = 411 | year = 2003 | pmid = 12697017] Early evidence suggested a benefit;cite journal | author = Corkeron M, Pereira P, Makrocanis C | title = Early experience with magnesium administration in Irukandji syndrome | journal = Anaesth Intensive Care | volume = 32 | issue = 5 | pages = 666–9 | year = 2004 | pmid = 15535491] however, according to a later report a series of 3 patients failed to show any improvement with magnesium; the author reiterated the experimental status of this treatment.cite journal | author = Little M | title = Failure of magnesium in treatment of Irukandji syndrome | journal = Anaesth Intensive Care | volume = 33 | issue = 4 | pages = 541–2 | year = 2005 | pmid = 16119507]

Geographic distribution

Reports of Irukandji syndrome have come from Australia, Hawaii, Florida, French West Indies, Bonaire, the Caribbean, Timor Leste and Papua New Guinea. It is presumed that cubozoan species other than "Carukia barnesi" are responsible for envenomations outside Australia.

Media demonstrations

The severity of the pain from an Irukandji jellyfish sting is apparent in the 2005 Discovery Channel documentary "Killer Jellyfish" on "Carukia barnesi", when two Australian researchers (Jamie Seymour and Teresa Carrette) are stung. Even under the "maximum dose of morphine" Teresa remarked that she "wished she could rip her skin off", and is later seen writhing uncontrollably from the pain while lying on her hospital bed. In one scene, Teresa's feet are shown contorting and digging into the bed - when the camera moves back, we see Teresa rubbing her face, her body is contorting in agony, and her legs are rapidly sliding and kicking around on the bed. Jamie, at his worst, is also seen writhing in pain, curled up in a ball and barely able to speak. Jamie said he wished that he was stung by "Chironex fleckeri" instead since "the pain goes away in 20 minutes or you die".

Another recent program that aired on the Discovery Channel entitled "Stings, Fangs and Spines" featured a 20 minute spot on Irukandji Syndrome. In the segment, a young Australian woman was stung and developed a severe case of Irukandji syndrome. In a testament to the severity of pain involved, a re-enactment (featuring the actual victim portraying herself) shows her screaming and violently thrashing around on the hospital bed in an almost convulsive state, for the bulk of the segment. She later commented that this unbearable pain lasted for hours, and added that "I didn't think it was possible for anyone to endure that level of pain without turning into a vegetable".

Footnotes

External links

* [http://www.nswseakayaker.asn.au/mag/48/Irukandjisyndrom.htm Irukandji Syndrome]
* [http://www.abc.net.au/news/newsitems/200604/s1620781.htm Report of successful treatment of Irukandji Syndrome]
* [http://www.avru.org/general/general_irukandji.html Australian Venom Research Unit]