Jellyfish Sting

Overview

What’s a Jellyfish?

A jellyfish is an animal that lives in the ocean. Some jellyfish look like small, clear blobs, while others are bigger and more colorful with tentacles hanging beneath them. 

What's a Jellyfish Sting?

When jellyfish hunt for sea creatures to eat, they sting them first to make them easier to catch. Jellyfish don’t eat people, but sometimes they sting them.

While jellyfish stings are painful, most aren’t emergencies. They usually get better in a few days to weeks.

Moon jellyfish, which are in all oceans, have mild stings. But stings from some other kinds of jellyfish — like the box jellyfish (also called the sea wasp) — are very dangerous, and can even be deadly. These jellyfish are most often found in Australia, the Philippines, the Indian Ocean, and central Pacific Ocean.

Top Things to Know

• Jellyfish stings happen when tentacles touch the skin and release venom.
• Most stings cause pain, red marks, itching, or tingling.
• Rarely, stings can cause serious symptoms like trouble breathing and need emergency care.
• Treatment may include removing tentacles with tweezers and rinsing with seawater.

How Do Jellyfish Sting?

Jellyfish sting their prey with their tentacles, releasing a venom that paralyzes their targets. Jellyfish stings leave thousands of very tiny stingers called nematocysts (NEM-uh-tuh-sists) in the skin. These stingers can continue to release, or "fire," jellyfish venom (poison) into the body.

Sometimes people who swim in the ocean get stung if they brush against a jellyfish. They also can get stung if they step on a live or dead jellyfish with bare feet. All jellyfish sting.

Signs & Symptoms

What Are the Signs & Symptoms?

A jellyfish sting might look like red marks. There’s usually pain, itching, numbness, or tingling.

When Should I Call an Ambulance?

Call an ambulance right away if your child has been stung and:

• has trouble breathing or swallowing
• has a swollen tongue or lips, or a change in voice
• has bad pain or feels generally unwell
• is nauseated or vomiting
• is dizzy or has a headache
• has muscle cramps
• has stings over a large part of the body
• the sting is in the eye or mouth
• might have been stung by a very dangerous jellyfish

Treatment & Care

How Do You Treat a Jellyfish Sting?

To deal with a sting:

• Remove your child from the water.
• Ask a lifeguard what to rinse the area with. In some areas of the world, it’s best to use vinegar, while in other areas, seawater is best. Don’t rinse with fresh water (like tap or bottled water) because that can make more stingers fire.
• Avoid rubbing the area.
• Use tweezers to pluck away any jellyfish tentacles still on the skin. Do not scrape off any stingers still in the skin with a credit card or anything else. The scraping might make stings worse.
• Have your child take a hot (but not scalding) shower or soak to help lessen pain. Avoid ice and ice packs.

Most kids don’t need to see a doctor for a jellyfish sting. If they aren’t feeling well and do need to be seen, the doctor might be able to suggest a cream or medicine to help them feel better.

Prevention

Can Jellyfish Stings Be Prevented?

Beaches with lifeguards are more likely to warn visitors about jellyfish. Look for a sign or warning flag (some beaches fly a purple warning flag when there's "dangerous marine life" in the water). Keep a small container of vinegar and a pair of tweezers in your beach bag just in case.

Before you even go to the beach, look online to see what kinds of jellyfish are in the area and what their stings are treated with. You can also ask the local health department.

Other Common Questions

Does Peeing on a Jellyfish Sting Help?

Urinating (peeing) on a jellyfish sting might make it more painful, so don’t do it.

What About a Sting From a Portuguese Man-of-War?

A Portuguese man-of-war looks like a jellyfish and may sting like one, but it isn’t a jellyfish. Although, you can treat a sting from a Portuguese man-of-war just like you would a jellyfish sting.