Jellyfish Stings and How To Treat Them

Jellyfish Stings and How To Treat them

b'more nat aquarium 2
Sea nettle (Photo: Baltimore Aquarium, Flicker Sharing).

Don't Pee on That Arm!

How many comedies have you watched where someone was stung by a jellyfish and the "hero" very selflessly offers to pee on the sting site? It really is just a comedy line, there is no truth in the myth and it can even make things worse! Yes, research as been done on this, and there's a great article in "Scientific American." If you'd like to read it, click here.  For this article I'm going to do two things:     1) Explain what happens when you get stung by a jellyfish and 2) Give you some treatment options.

So you're swimming happily along in the ocean or bay and all of a sudden it feels like someone has smacked you with a wet towel filled with yellow jackets. If this is the case then you've probably been stung by a jellyfish. First, you should always know where you're swimming and the types of jellyfish that are around. Where you're swimming and the salinity of the water will determine what types of jellyfish you might find.     Since we're not in Australia we don't have to worry about the killer box jellyfish, but there are several other species around that can still pack a punch. For this article I'm going to focus on species found in the Chesapeake Bay during the summer, specifically Chrysaora quinquecirrha (Cry'-sore-ah kwin-kah-sehr'-ah) or the sea nettle.

b'more national aquarium flicker
Sea Nettle (Photo: Baltimore Aquarium, Flicker Sharing).

So exactly What Happens When You're Stung By A Jellyfish?

Let's get one thing straight about jellyfish. They're the animal everyone loves to hate, but they're a super important part of the food web and they're even a freshwater source for turtles to eat/drink. THEY ARE NOT OUT TO GET YOU. Jellyfish are plankton. Planktos in Greek literally means "wanderer" or "drifter." They can't actively swim like a fish, they are at the whim of the tides. Yes, they can move up and down slightly, but they can't swim and they're not coming after you like Jaws.

Tentacles are how jellyfish feed, and most jellyfish stings are usually accidental. Considering they don't have eyes, a brain, a heart, legs, lungs, or much else, tentacles are about all they've got. The tentacles hang in the water like thin fishing ropes, but the true "lines" are hidden, along with their hooks or barbs. Picture hundreds of tiny little turkey baster bulbs in rows (or the small blue snot-suckers you use on infants) on each tentacle. These little bulbs are stinging cells called cnidocytes (nigh-do-sights), but their more fun name is cnidoblasts (nigh-do-blasts) because the cells literally explode when touched.  In each cnidoblast is a nematocyst (knee-mat-O-cyst), which are coiled up (hollow) filamentous lines that have sharp needle-like barbs. The barbs have venom that can be pumped into them through the filaments.

Jellyfish stinging cells (Photo: Wiki Commons).

When a jellyfish tentacle is touched the cnidoblasts literally "blast" open. The lids of their cells fly off and the coiled lines inside fires out and stabs the offending object, pumping venom at the same time (it can take less than 700 nanoseconds!). In some species of jellyfish the filamentous threads break off and wrap around the "prey" or may remain on your body. Remember this bit, it's important.

Here is an image of a nematocyst that has fired. This is under 1,000x magnification.

Marc Perkins flicker
Nematocyst that has fired its filament (Photo: Marc Perkins, Flicker Sharing).

Why Does Jellyfish Venom Sting?

The venom of jellyfish has a protein in it called porin (pour-in). This protein can be found in corals, sea anemones, and all jellyfish. Porins are a mixture of enzymes, pore/hole forming toxins and neurotoxins. The amount and mixture determines reaction you'll get. Essentially porins, with the help of their stingers, can penetrate through the cells of fish, invertebrates, and even humans. Depending on the species of jellyfish, the porins can do anything from causing a stinging sensation on the arm (like our local Bay jellyfish), or an immunological effect, all the way to instigating full cardiac arrest and cell rupture.     Jellyfish stings are complex things with complex chemicals and interactions.

How Can I Treat Stings?

First, a disclaimer. I will present to you what has worked for me in the field, and the most recent science, but I am not a doctor. This article constitutes suggestions only. It's up to you to seek medical treatment and intervention if you're stung. Take this for what it is, advice from someone who works around jellyfish daily and has had to deal with a lot of jellyfish stings.

Sea Nettle (Photo: Wiki Commons, NOAA).

STEP 1: Assess The Sting and The Source

If you know the type of jellyfish it can help you know how to treat it. For this article the sea nettle is the most common one we see. You may need to research those in your area. If you have a sting that covers more than 50% of an appendage you should probably seek medical attention right away. The same is true if you are allergic to bees or require an epi-pen. Even if you don't, if you start to feel numbness, tingling, swelling throat, and difficult breathing then GET HELP! Call 911.

STEP 2: Remove the Gooey Stuff ONLY WITH SALT WATER!!!

I can't emphasize strongly enough that you need to get the jellyfish off as quickly as possible. You can use your fingers to pinch the bell and remove it, or use a stick or credit card to scrape it off. Don't use sand, this can abrade the skin and also cause more of the stinging cells to fire. If you have to use a towel or fabric. It's important to remove tentacles because even if they are not attached to the jellyfish they can still sting and their stinging cells can still fire!  Remember, I also said that the filaments can break off and they can still be pumping venom.

When you rinse tentacles and goo off ONLY USE SALT WATER. Do not use fresh water. There's a lot of sciency stuff to this, but think of it this way. Jellyfish tentacles are floating in saltwater. If you try to wash the tentacles off with fresh water you're changing the osmotic balance (there's more salt inside the cell which will want to "come out" into the fresh water), and will cause the stinging cell to fire. This is also why you don't pee on jellyfish stings. If your pee is less salty than the ocean water you're in, then your pee may cause even more nematocysts to fire and more venom to be pumped into the victim!!    Besides, do you really want to wave your willy around where there are jellyfish tentacles and stinging cells lurking?

White vinegar, though any vinegar will work (Photo: Flicker Sharing, JeepersMedia).

STEP 3: Rinse With Vinegar, Apply Baking Soda or Unseasoned Meat Tenderizer as a Paste.

Once the physical goo is removed then you can start bathing the site in a vinegar rinse, or soaking the appendage in a white vinegar bath.  I've found that you have to do this for a while. You can't just do 30 seconds and be "done." Most sources say around 10-20 minutes. If you're using baking soda or unseasoned meat tenderizer, then make it into a paste and put it on the wound. For kids, don't leave the meat tenderizer on more than 15 minutes (they can get a rash or it can irritate their skin).

STEP 4: Soak In Hot Water

Now if you're like me the last thing you want on your tender, hot stung flesh is something else hot like hot water.    It sounds counter intuitive, but heat helps to neutralize the toxins in the venom and alleviate the stinging sensation and pain. It's best to use water that is around 110-115 F or 45 C. Immerse the appendage for about 20-30 minutes. If you can't immerse it then take a hot shower. Cold packs also feel good but they're not as good at taking the sting away. If you'd like to know more read this paper from the National Institute of Health.

STEP 5: Lotions and Creams

After initial treatment the sting is going to hurt for a while (how long depends on a wide variety of factors such as type of jellyfish, duration of exposure, and even your own skin chemistry). Treat the stings with common over-the-counter hydrocortisone creams, aloe, or lidocane based creams for numbing.

Jellyfish under water (Photo:

Other Things To Consider

There are some interesting new finding about jellyfish stings, including the idea that zinc can be useful for treating stings too. For the most part it's best to avoid being stung. You can wear long clothing, jellyfish suits, or even buy sunscreen from Nidaria Technologies that has ingredients that keep jellyfish tentacles from stinging or attaching.

Even though jellyfish sting  they're not out to attack you or "get you."    They are just floating and drifting around, doing what they do, catching fish and trying to stay alive. Respect the jellyfish, and their waters, and you'll be fine.