According to the research, carried out with the support of ISDIN and CaixaResearch of the "la Caixa" Foundation, the use of vinegar as a rinsing solution in first aid protocols can be harmful if it is not applied to the correct species.
First aid protocols for dealing with jellyfish stings have always believed that applying vinegar to the affected area was the best remedy. However, a new study led by the Institut de Ciències del Mar (ICM) in Barcelona has warned that not all jellyfish stings should be treated with vinegar.
The research, carried out with the support of ISDIN and CaixaResearch of the "la Caixa" Foundation as part of the RECLAIMED project, was recently published in the specialized journal Toxins. According to the work, the most important step in first aid protocols is to prevent a second poisoning by safely removing the remains of tissue or stinging cells (cnidocytes) adhering to the skin.
To do this, the research team recommends applying a rinsing solution to the affected area after a sting, which should not be vinegar in the case of Pelagia noctiluca stings, the species that causes most incidences on Mediterranean beaches. This is because its application produces direct and immediate activation of the stinging cells of P. noctiluca, making its use counterproductive in first aid protocols for this species.
In contrast, vinegar does produce an inhibitory effect on the discharge of stinging cells of the Carybdea marsupialis species, one of the most venomous jellyfish in the Mediterranean, and can therefore be safely used to wash the area affected by a sting of this species.
"Our finding highlights the importance of recognising the species that has caused the sting and establishing the most appropriate action protocol in each case. We have shown that vinegar cannot be used universally. We must base the guidelines of the protocols for Mediterranean species on scientific evidence to avoid bad practices", states Ainara Ballesteros, researcher at the ICM and first author of the study.
To carry out the study, the research team studied the possible effects of vinegar on venom discharge in the case of two species belonging to different classes, P. noctiluca and C. marsupialis, observing the effect of this compound on the discharge of cnidocytes in each case. In addition, inhibitory tests were carried out by stimulating discharge chemically and naturally. For the experiments, researchers used specimens collected in Barcelona and Denia (Alicante) beaches.
"Combining traditional methodologies with more avant-garde ones that more closely resemble the reality of the stinging event in the marine environment has been crucial in obtaining the results of this research", exposes Josep-Maria Gili, ICM researcher and co-author of the study.
According to this work, the fact that the same rinsing substance has completely opposite effects on the discharge of cnidocytes could be due to the great variety of types and subtypes that exist between species. Although the defence mechanism is the same in all kinds of jellyfish, the toxicity and components of the venom can be very different.
"Our study highlights the differences between two different species, but there is still a lot of research ahead of us. It is essential to study the involvement of vinegar in other species of cnidarians –the phylum to which jellyfish belong- that also have an impact on our beaches, such as the jellyfish Rhizostoma pulmo, the anemone Anemonia sulcata or the hydrozoan Aglaophenia pluma", conclude Gili and Ballesteros.