Jellyfish Stings – How to Handle Them

Have you ever gone to the beach, been stung by a jellyfish and wondered what to do about it? Also why does it hurt so much? These are questions I pondered while I was at the beach during Memorial Day weekend, and I thought I would share my knowledge and research with you.


Tentacles of the jellyfish are covered with thousands of cnidoblasts. The cnidoblasts hold nematocysts inside of them, and the nematocysts house stinging threads. The nematocysts effectively act as a spring-loaded hypodermic syringe. These are harpoon-like structures that are on the inside of the cnidoblasts; They deploy as the tentacle recoils. The nematocysts fire their harpoons and this is the actual ‘sting’ of the jellyfish. The nematocysts shoot out of the cnidoblast as a reflexive response when the tentacle touches anything. In nanoseconds, the venom penetrates the skin by way of these harpoons or hypodermic apparatuses. The venom causes a reaction on the skin that we interpret as a sting. What is painful in the venom is typically a protein called ‘porin’. This is a protein found in the venom of all jellyfishes. The remainder of the venom is a concoction of various other proteins and chemical reactants. The same type of venom orand proteins are found in corals and sea anemones. Once in the skin, the porin creates instant holes in the cells that it touches (porin creates pores). Therefore, once the venom is injected into the skin the porin attacks the cells and blast holes in nerves, blood vessels, skin cells, muscles, and whatever else it comes in contact with. This causes the painful reaction. Then there is an immunologic reaction, sort of like an allergic response on top of that. Venom is injected in thousands of locations on your body in microscopic amounts, but it is enough to cause a severe reaction in humans. For the prey of the jellyfish the sting can kill them. The venom is a neurotoxin for small creatures that it eats, but for humans it is just annoying and painful. However, there are some species that can kill the humans, such as the Box Jellyfish and the Man-of-War.


Typically your instinct is it to rinse it with water, but that is the last thing that you should do. Freshwater (ice, water, and urine) can change the fluid balance around the nematocysts in your skin and this actually triggers the release of even more venom. Therefore, rinsing with seawater or saltwater is better. So if you're at the beach and a sting happens use seawater to rinse the area, not ice or fresh water. Before rinsing you should rub the skin with something to remove the remaining tentacles. If you happen to have tweezers use them to pull the tentacles out, and as a last resort use sand. You typically would not want to put sand in the wound, but if that is your only option to remove the stingers, then that is what you should do. Afterwards put vinegar on the skin and soak for 15-30 minutes. Vinegar is an acid, and changes the pH balance so the nematocysts do not release the toxin. It also deactivates the toxin. A pressure dressing sometimes helps as well. Heat can help to deactivate the toxin in addition to that. Warm seawater would be the best rinse. You can also continue to rinse with seawater and then use 70% isopropyl alcohol or rubbing alcohol. If a stinger happens to hit the eye, use artificial tears to remove it and you can dab the skin around the eyes with a cloth or towel soaked in vinegar. Obviously, you do not want to put vinegar directly in the eye. You can also use a base instead of an acid. Baking soda is often recommended. Either way, you are changing the pH balance such that the nematocysts are not releasing the venom. Tobacco can help because there is a substance in tobacco that numbs the skin and deactivates porin. You can mix tobacco leaves from dip or cigarettes with water into a paste and use it as a sap. Meat tenderizers work by way of enzymes to deactivate the venom. These break down the protein in the venom and deactivate it. In addition, papaya has another helpful enzyme called papain that acts as a way to denature (break down) the venomous proteins. Finally, if you happen to have Benadryl or hydrocortisone lotion, you can apply those to reduce the inflammatory response. This will help with symptom control but would not do anything about the venom. Hopefully, this helps you create a basic first aid kit for jellyfish stings. You should probably have some vinegar and/or baking soda and some clean washcloths to try to get the stingers out of the skin when this occurs. Always seek medical attention if there is any change in breathing, heart rate, level of consciousness, or any other indicators of an anaphylactic reaction.