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Anne Marie Helmenstine, Ph.D.

How to Treat a Jellyfish Sting

By August 4, 2009

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Jellyfish Sting (Anne Helmenstine)

One of the benefits of being a freelance writer and consultant is being able to live anywhere. I live near the beach, which is where I head whenever the surf is up. The Carolina coast is wonderful, but it is home to some jellyfish that can leave a painful sting. We encountered one of these today. How did we know? Not that many things will sting like a hundred wasps at once out in the surf. We didn't get any tentacles stuck to us, which would have been another way to tell it was a jellyfish. The real giveaway was seeing the actual animal floating in the tide.

A little practical chemistry helped to minimize the pain and damage from the sting. Now, we were fortunate because we saw the jellyfish that caused the sting and could rule out a man-of-war sting, which is different from a jellyfish sting. Here's what you do when you're sure it was a jellyfish that caused the sting:

  1. Get out of the water. (note: you don't have to be in the water to get stung in the first place. A dead jellyfish on the beach can still sting you.)

  2. If the victim is having difficulty breathing or is experiencing nausea or dizziness (all possible symptoms of a reaction to the venom), call 911 or seek emergency medical treatment. A reaction to the venom is like any other allergic reaction. It's normal for the sting to burn intensely; that in itself isn't a symptom of a reaction.

  3. Remove any pieces of tentacle. You don't want to touch the tentacle pieces, so use a shell or credit card or the edge of a towel. Many jellyfish have clear or pale tentacles. If you see deeply-colored tentacles and did not see the animal that caused the sting, treat the sting as if it came from a man-of-war, just to be safe.

  4. Rinse the affected area with seawater. Do not use fresh water! This will cause any nematocysts (stinging cells) that haven't already discharged to sting. Fresh water may significantly worsen the injury. That's chemistry in action, too. Changing the osmotic pressure around the nematocysts will cause them to fire.

  5. You can use chemistry to inactivate the toxin in the venom. You are basically inactivating a protein, which you can achieve by changing its temperature or pH or by breaking it apart. Applying heat is the safest method of inactivating the toxin because it penetrates the skin and won't cause stinging cells to fire and release more venom. Hot sand works, too. If you are absolutely sure the sting came from a jellyfish, you can apply a weak acid or base or an enzyme to inactivate the toxin. Vinegar, baking soda, and meat tenderizer all work. Urinating on the sting usually does not work and is not recommended. One of the more recently recommended treatments is to apply lidocaine (such as you would find in sunburn relief products), which immobilizes the stinging cells so they can't release more venom while relieving the pain or itching of the sting. That is the method we used this time around (this was by no means the first time anyone in my family had been stung). The lidocaine worked very well.

  6. We followed up with Benadryl gel, since an antihistamine reduces swelling and can combat potential itching associated with the sting. Some people apply aloe or a hydrocortisone cream.

  7. Any of the usual over-the-counter pain relievers are good for pain.
If you are visiting the beach, it's a good idea to carry some form of jellyfish treatment with you. The chemicals that can inactivate the venom or even immobilize the stinging cells are easy to find and effective. Prompt treatment of a sting can result in an injury that heals in a day or so. Belated treatment or incorrect treatment can leave you with a much more serious injury, potentially leaving scars.

You can prevent getting stung in the first place by wearing protective clothing. Jellyfish can't sting through a swimsuit or wetsuit. Another option is to wear pantyhose. Don't panic when you see a jellyfish. Several species cannot sting you. Those that can sting aren't in a position to chase you. Jellyfish float in the current, so if you move away from them you can usually get clear.


August 5, 2009 at 12:00 pm
(1) Ron says:

Or you could use StingMate Jellyfish sting 1st aid gel…Lidocaine free and it works…life guard tested…proven effective…convenient easy to use spray bottle….

December 20, 2012 at 3:31 am
(2) laura says:

i got stungby a blue blubber today and it hurt! i wet straight to the unit and hopped in a hot shower (i made sure that i was able to stand the hot) which took alot of the pain away.

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