Jellyfish Stings

Overview

What are jellyfish stings?

Jellyfish are sea creatures that live in all of the world’s oceans. They have soft, bell-shaped bodies with lengthy tentacles.

Many jellyfish have stinging cells called nematocysts in their tentacles. These cells contain a poisonous substance (venom) that helps jellyfish protect themselves. The venom also helps them capture food by stinging it.

Some of the jellyfish whose stings can be serious include box jellyfish, lion’s mane, Portuguese man-of-war, and sea nettle.

Symptoms and Causes

What causes jellyfish stings?

People may come into contact with the nematocysts of a jellyfish when they are swimming in the ocean or walking on the beach. This contact can cause the venom from the nematocysts to be injected into the body. More than 150 million jellyfish stings happen in the world each year.

Depending on the type of jellyfish and how much of the skin touches the venom, the sting can cause pain or other serious health problems. Some jellyfish stings can be life-threatening. It is important to get medical help if you have severe symptoms after a jellyfish sting.

What are the symptoms of jellyfish stings?

The symptoms of jellyfish stings depend on the type of jellyfish you made contact with. Mild jellyfish stings usually cause minor pain, itching, and, in some cases, a rash.

More serious jellyfish stings can cause greater harm. You should get medical help if you have more severe symptoms, including:

  • Difficulty breathing
  • Chest pain
  • Muscle cramps
  • Skin blistering
  • Numbness or tingling
  • Nausea or vomiting
  • Difficulty swallowing
  • Worsening redness, rash or pain if a sting gets infected

Management and Treatment

How are jellyfish stings treated?

Most people do not need to see a doctor for a jellyfish sting. Symptoms of a jellyfish sting usually go away after a few hours. Sometimes, a rash remains from a few days to two weeks.

You can treat mild jellyfish stings with the following steps:

  1. If you are stung at the beach or in the ocean, pour sea water onto the part of your body that was stung. Do not use fresh water.
  2. Use tweezers to remove any tentacles you see in your skin.
  3. Next, apply vinegar or rubbing alcohol to the affected area to stop the burning feeling and the release of the toxin.
  4. After you have poured vinegar on the site, apply shaving cream or a mixture of baking soda and sea water. When this is dry, scrape the mixture off with a credit card.
  5. To help reduce the pain, apply calamine lotion or hydrocortisone cream. You can also use an ice pack or hot water to help with the pain and swelling.

Your doctor may treat more serious jellyfish stings with medications to relieve pain, neutralize the venom’s effects (antivenin) and reduce the itching and rash (antihistamine).

Prevention

How can jellyfish stings be prevented?

People can be stung by a jellyfish any time they are in or near the ocean. To reduce your risk of being stung:

  • Ask lifeguards or park rangers if any jellyfish are present around your beach. (Some beaches post a warning flag when jellyfish are reported.)
  • If you surf or dive in the ocean, wear a protective body suit.
  • Never touch a jellyfish that has washed up on shore. Dead jellyfish still have venom in their tentacles that can sting on contact.

Last reviewed by a Cleveland Clinic medical professional on 05/22/2018.

References

  • Cegolon L, Heymann WC, Lange JH, Mastrangelo G. Jellyfish Stings and Their Management: A Review. Mar Drugs. 2013 Feb; 11(2): 523–550.
  • National Wildlife Federation. . Accessed 5/23/2018.Summertime First Aid: Jellyfish Stings (http://blog.nwf.org/2010/08/summertime-first-aid-jellyfish-stings/)
  • Wilcox CL, Yanagihara AA. Heated Debates: Hot-Water Immersion or Ice Packs as First Aid for Cnidarian Envenomations? Toxins (Basel). 2016 Apr; 8(4): 97.
  • Virginia Institute of Marine Science. . Accessed 5/23/2018.Jellyfish Stings (http://www.vims.edu/bayinfo/jellyfish/stings/index.php)

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