What You Need to Know About Bluebottle, Irukandji, and Box Jellyfish Stings
A guide to recognising risk, first aid priorities, and when urgent care saves lives
Why jellyfish stings matter in Australia
Australia’s coastal waters are home to several jellyfish species that cause stings of very different severity. Bluebottles are common and usually painful but not life-threatening. Irukandji and box jellyfish are rare but medically serious. Understanding the differences helps you respond appropriately and seek care without delay when it matters most.
Bluebottle (Portuguese man o’ war) stings
Bluebottles are frequently washed ashore along eastern and southern coastlines. Their stings cause immediate, intense pain with red, whip-like marks on the skin. Pain often settles over hours to days, though tenderness may linger. Bluebottle stings are rarely dangerous, but they can be very distressing, especially for children.
First aid:
Hot water immersion (as hot as tolerated, not scalding) for 20 minutes helps relieve pain. Remove visible tentacles carefully. Vinegar is not recommended for bluebottle stings.
Irukandji jellyfish stings
Irukandji jellyfish are tiny and difficult to see. The initial sting may feel mild or go unnoticed, but severe symptoms can develop 20–40 minutes later. These may include severe muscle and abdominal pain, headache, nausea, sweating, anxiety, and a feeling of impending doom. This reaction, known as Irukandji syndrome, is a medical emergency.
First aid:
Apply vinegar to the sting area if available and seek urgent medical care immediately. Hospital treatment is essential.
Box jellyfish stings
Box jellyfish stings are rare but extremely dangerous. They cause immediate, severe pain and visible ladder-like skin marks. Large stings can lead to rapid collapse, heart rhythm disturbances, or cardiac arrest within minutes. These stings are life-threatening.
First aid:
Apply vinegar immediately to inactivate unfired stinging cells and call emergency services. Begin CPR if the person collapses.
Why symptoms vary so much
Different jellyfish venoms affect the body in different ways. Bluebottle venom mainly causes local nerve pain. Irukandji and box jellyfish venoms affect the nervous system, heart, and blood vessels. The size of the sting, amount of venom, and the person’s health all influence severity.
Reducing risk when swimming
Pay attention to local warnings, signage, and stinger season advice. Wearing protective clothing such as stinger suits, avoiding swimming during known high-risk periods, and following lifeguard instructions reduce risk. Beaches with vinegar stations and patrols provide additional safety.
When GP follow-up helps
A GP review is useful after any sting if pain persists, skin reactions worsen, signs of infection develop, or you feel unwell in the days following exposure. GP review also supports education, reassurance, and future prevention planning.
This article provides general health information only and does not replace medical advice. Seek urgent medical care or call emergency services for suspected Irukandji or box jellyfish stings, or if severe symptoms occur after any jellyfish sting.