Also known as the Irukandji, Carukia is a small, virtually invisible, box-jellyfish with a single tentacle in each corner (carybdeid). The sting may be quite mild, and is sometimes not visible on the skin. However, some 30 minutes after the sting a number of severe systemic symptoms called the Irukandji syndrome occur. The symptoms include severe low back pain, muscle cramps in all 4 limbs and the chest wall, restlessness, anxiety, and a “feeling of potential doom” (often shared by the first aider!). Severe hypertension and pulmonary oedema may occur, which may become life-threatening, although no deaths have been reported to date. The effects are believed to be due to the excess release of catecholamines.
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