People who swim in the ocean may encounter jellyfish. These floating sea creatures (which are not fish) have long tentacles equipped with tiny barbs supplied with venom. The most poisonous is the box jellyfish, Chironex fleckeri. Over the years, divers have developed a number of tactics for dealing with jellyfish stings. Perhaps the most popular is vinegar.
Vinegar for Box Jellyfish Stings:
Q. I was snorkeling off a dive boat in Hawaii when I became tangled in very toxic box jellyfish tentacles. Several others from the boat also came in contact with them. One young man was severely stung over 2/3 of his body.
The boat crew had a gallon jug of vinegar on board for just such emergencies. First, they hosed us off with fresh water to rinse away loose tentacles. Then they poured vinegar on the stung areas. This seems to neutralize the toxins temporarily. At that point, they had us scrape away anything clinging to our skin. Paper towels were soaked in vinegar and we were told to gently hold the wet towels on our skin, periodically re-soaking with vinegar. Every time we removed the soaked paper towels, some of the pain returned, but it was obvious the vinegar helped.
Home Remedies Stymie Science:
A. Researchers seem to have had difficulty confirming that home remedies for box jellyfish stings are effective. Removing the loose tentacles immediately is important, so they don’t continue to discharge poison. One study compared hot water and icepacks and found no difference between the effects (Medical Journal of Australia, April 3, 2017).
The American Heart Association and the American Red Cross recommend that jellyfish stings should be rinsed with vinegar for 30 seconds or more. In theory, the acetic acid neutralizes the venom of the Portuguese man-of-war jellyfish (Circulation, Nov. 2, 2010, Suppl. 3). However, the Portuguese man-of-war is a different species from the box jellyfish and may respond differently.
One study from Hawaii found that scraping and seawater rinsing actually made the box jellyfish stings worse (Toxins, March 15, 2017). Vinegar helps, but for these types of stings the researchers found that a proprietary product, Sting No More®, was most effective. It contains copper gluconate, magnesium sulfate and urea.