Vinegar should be used on all jellyfish stings

What the research found

Some reviews and a case report say vinegar (dilute acetic acid) inactivates venom. A 2007 review suggested rinsing serious stings with seawater or vinegar. A 1992 case report said the same for Portuguese man-of-war stings. These are low-quality sources and cover particular species.

Trials in volunteers give a less clear picture. A 2002 randomised trial on Carybdea alata stings compared hot water with vinegar or papain meat tenderiser. Hot water eased pain more than the comparison treatments, by an average of 1.1 cm on a 10 cm pain scale after two minutes of treatment.

A 2016 randomised trial stung 96 people with Chrysaora chinensis. Papain reduced pain slightly compared with placebo, but the other treatments tested, including acetic acid, did not clearly help. Stings differ by species, so one treatment is unlikely to suit all of them.

What it doesn’t mean

• This doesn't mean vinegar is harmful. It means the evidence doesn't show it works for every jellyfish sting.
• Call an emergency number straight away if a child has trouble breathing or swallowing, hoarseness, confusion, fainting, or hives or swelling over the body. Severe reactions are rare, and most come from box jellyfish.
• If you're unsure which jellyfish stung your child, or the sting is severe or covers a large area, get medical help and ask a GP or local first aid provider about the right treatment for your area.