What’s the Best Way to Treat a Jellyfish Sting?

August = peak jellyfish season at the Jersey Shore. ER doc and director of travel medicine at Jefferson University Hospital Ken Neuburger shares what to do if you get stung

Illustration by Justin Renninger

Forget about sharks — as August approaches, the Jersey Shore will enter its peak jellyfish season. Though these creatures aren’t typically deadly – not the ones we get here, anyway – they are slimy, creepy, and just plain unpleasant if they happen to sting you. And since myths abound in regards to the best treatment (should you really pee on a sting?), we asked Jefferson University Hospital Director of Travel Medicine and ER doc Ken Neuburger for tips on what to do the next time you’re stung.

Wash it off.
A jellyfish’s tentacles carry hundreds of thousands of nematocysts, the microscopic, harpoonlike apparatuses that cause the stinging reaction. After an encounter with a jellyfish, residual nematocysts can sit on the skin, so it’s important to wash them off before they worsen the reaction. “The most common thing used to wash off the nematocysts that are firing is vinegar,” says Dr. Neuburger, noting that the acidity nullifies the nematocysts. And what about pee? It works, but not as well as vinegar. (Urine has a pH that ranges from 4.6 to 8.0 and vinegar has a pH of 2.4).

Didn’t remember to toss a bottle of vinegar in your beach bag and don’t want to bare it all at the Shore? “Wash it off with sea water,” says Dr. Neuburger, noting that fresh water will cause the nematocysts to fire more.

Make a paste with sand.
To further clear the affected area, form a paste with sea water and sand. Place it on the afflicted area and then wipe it off. “One good swipe should be enough [to clear the rest of the nematocysts],” says Dr. Neuburger.

Ease swelling.
If there is swelling, use “cool compresses, but not ice,” says Dr. Neuburger. “Ice can increase the damage to the skin [by causing] frostbite.” Hydrocortisone cream can also be used, as its anti-inflammatory properties shrink blood vessels. Apply two to four times a day, depending on the severity of the swelling. Benadryl, an antihistamine sold over-the-counter, also helps with swelling.

If allergic, seek help.
Though there’s no way to test for a jellyfish sting allergy, it is definitely possible for a jellyfish encounter to produce an allergic reaction. “Like any other allergy, it might start with hives,” Dr. Neuburger says. “There’s no way to tell what’s going to happen, so you treat it like any other severe allergic reaction.” That means go to the hospital, because what starts as hives could progress into something far worse, such as a fever, difficulty breathing, or the closing of the throat. “The speed [of a severe reaction] is variable,” he notes, explaining that some people are more sensitive than others, as is the case with all allergic reactions. If it’s a really bad reaction, the progression from hives to a throat closure can be minutes.