Jellyfish Sting Mimics the Bends

In the April, 1998, issue we reported on divers in Indonesia who experienced mysterious symptoms mimicking the bends only to find out later that the symptoms were the result of a jellyfish sting. The Medical Journal of Australia reports a similar case off the Great Barrier Reef which they label “Irukandji” syndrome, envenoming by the cubozoan jellyfish Carukia barnesi.

It started when a 28-year-old experienced diver was diving off Queensland at a depth of 40 feet. He had a feeling of disequilibrium, made a controlled ascent, and removed his gear. His vague malaise was accompanied by aching pain in the groin and thighs and numbness in the fingers and toes. This rapidly progressed to severe pain in the skin, muscles, face, jaw, testes, and lumbar region along with profuse sweating and agitation.

When he reached a hospital six hours later, he was in great pain. The initial treatment was with 100% oxygen and pethidine (intramuscular and intravenous), but when he mentioned seeing a small jellyfish and feeling a slight irritation on his right arm, physicians decided Irukandji syndrome was the culprit and put him on intravenous morphine for 10 hours. Severe pain is not the only consequence of the sting; without proper treatment, heart failure may occur.

The Irukandji, for which there is no known anti-venom, emerges in summer in the southern hemisphere. Dr. Mark Little of Cairns said studies point to increased activity during north-northeast and northnorthwest winds and during periods when it was hotter and drier than average. Recently a woman in her 20s was put on life support for a week in Cairns after being stung at the outer reef, which hundreds of divers and snorkelers visit daily.

In 1996, 62 people were stung in the Cairns area by the Irukandji, which compared with only two stings by the sometimes-fatal box jellyfish. Cairns Base Hospital studies found that half the patients were released after four to six hours but the remaining half were more severely affected and were admitted to the hospital.

A member of the box family, the Irukandji is tiny, only 2 cm. across the bell. Stings are frequently not noticeable. Patients initially need to be calmed and have vinegar applied to the area of the sting to deactivate the stinging cells. “Irukandji stings are creating significant health problems in far north Queensland,” Dr. Little said.

For divers in Northern Australia, Papua New Guinea, and Indonesia, wearing skins is always wise. And it’s also wise to be aware of the unique symptoms of Irukandji syndrome.

From reports in The Medical Journal of Australia and the Australian Associated Press