With this good weather continuing in Ireland, many are tempted to go for a swim. However, last year Ireland had two of the most dangerous jellyfish species coming in around the coast – the Portuguese man o’war, and the Lion’s Mane jellyfish. And if you are stung, new medical advice is to apply vinegar!
For nearly a decade, the standard practice in Ireland for treating stings by the Portuguese man o’ war jellyfish (Physalia physalis) is to rinse with seawater and then apply ice. However, in a new study published last week, scientists from NUI Galway have found those measures are actually among the worst things to do if stung.
Collaborating with jellyfish sting experts from the University of Hawai‘i – Mānoa, the NUI Galway scientists re-evaluated which commonly recommended first aid actions (such as rinsing with seawater) are the most effective for Physalia stings. Their results, published in the journal Toxins, overturn the current advice, and show that the best first aid is to rinse with vinegar, to remove tentacles and then immerse in 45°C (113°F) hot water (or apply a hot pack) for 45 minutes.
There are two species of Physalia, the Portuguese man o’ war (Physalia physalis) which occurs in the Atlantic, and the bluebottle (Physalia utriculus) which occurs in the Pacific. Both species are among the most recognisable stinging jellyfish with their bright blue tentacles and colorful inflated floating sails. Just last September, armadas of these painful stingers came ashore in Ireland. The Portuguese man o’ war is not a true jellyfish, but a siphonophore, a closely-related group of colonial animals.
Dr Tom Doyle, Lecturer in Zoology from the School of Natural Sciences at NUI Galway, said:
“We had unprecedented numbers washing up from Cork to Donegal last September. Thankfully we had very few reported stings given the time of year. However, if this event had occurred during the summer months, then we may have had hundreds of stings. Our new evidence-based research conclusively shows that the best first aid for a man o’ war sting is rinsing with vinegar or a Sting No More Spray, developed by the University of Hawai‘i – Mānoa, followed by the immersion of the injured area in hot water or the application of a hot pack.”
Commenting on the research, Dr Wilcox, said:
“Physalia are often listed as exceptions to any blanket first aid recommendations for jellyfish stings. Without solid science to back up medical practices, we have ended up with conflicting official recommendations around the world, leading to confusion and, in many cases, practices that actually worsen stings and even cost lives.”
But although man o’ war stings are common around the world, there was little agreement on the best first aid responses to such injuries until now. Dr Tom Doyle and PhD student Jasmine Headlam at NUI Galway collaborated with Dr Christie Wilcox, lead author of the paper and postdoctoral fellow with the Pacific Cnidaria Research Laboratory at the University of Hawai‘i, and her colleague Dr Angel Yanagihara, assistant research Professor at the University’s Pacific Biosciences Research Center.
Dr Wilcox and Dr Yanagihara first examined box jellyfish, some of the deadliest jelly species in the world, finding that common practices such as applying urine or scraping away tentacles only make stings worse. Applying these new rigorous testing methods to man o’ war stings was the obvious next step, in which they collaborated on with Dr Doyle at NUI Galway.
The results from opposite sides of the world aligned beautifully. The venom delivered by a man o’ war sting was lessened if the sting site was rinsed with vinegar, regardless of which species of Physalia was used. The scientists showed that vinegar inhibited the animals’ stinging cells from firing, thus safely removing tentacles and stinging cells that can remain adhered to the skin and continue to deliver venom over time.
Meanwhile, PhD student Jasmine Headlam is already working on her next research project.
“After the Portuguese man o ‘war, the most venomous jellyfish in Irish waters is the lion’s mane jellyfish”
Lion’s mane (Cyanea capillata) are responsible for more bad jellyfish stings in Ireland than any other species, and in many such cases, the victims end up in the hospital. Ms Headlam added:
“We are currently doing similar experimental work on the lion’s mane jellyfish and hope to submit this work for publication in due course.”
View this short video which summarises the results of the study: https://www.youtube.com/watch?v=ZirOV9wJ2jo&feature=youtu.be