What to do if you're stung by a jellyfish

What does a jellyfish sting look like?

The symptoms of a jellyfish sting usually include an itchy, painful rash, which blisters, before filling with pus and rupturing.

The jellyfish might also leave a print of its tentacle, which usually shows in red, brown, or purple marks. The skin will feel very sensitive and sore.

What type of jellyfish sting is most dangerous?

Many jellyfish are harmless to humans, but a sting can become more severe if it comes from certain species.

For example, box jellyfish like sea wasps can cause intense pain and life-threatening reactions in people. They are found in the Pacific and Indian oceans.

Other types of jellyfish that cause severe reactions include:

• Bluebottle jellyfish - found in warmer seas.

• Sea nettle - found along the northeast coast of the United States.

• Lion's mane - found in northern regions of the Pacific and Atlantic oceans.

• Sea wasp - found around Australia and Southeast Asia.

How long you are exposed to the stingers also impacts the severity of a sting, as does how much of your skin that is affected. Children are most likely to have severe reactions, along with people who have other health conditions.

How long does a jellyfish sting last?

Abbas Kanani, a pharmacist at Chemist Click, explains that most people will feel an intense pain immediately after the sting, which usually lasts between 1-2 hours.

The itchy sensation, on the other hand, can last up to a week, and several weeks in more severe cases.

Some jellyfish stings may cause a reaction across the entire body, including:

• Nausea.

• Weakness.

• Muscle spasms.

• Stomach pain.

• Excessive sweating.

• Headaches.

How to treat a jellyfish sting

When to see a doctor about a jellyfish sting

If you are holidaying in a foreign country, after following the above steps, Kanani strongly advises seeking medical treatment, since you’re likely to be less informed on what has stung you - it’s better to be safe than sorry!

If your tetanus vaccination is not up to date, you will need to see a doctor to get a booster shot.

In rare cases, jellyfish stings can be life-threatening. As the sting develops, there’s a chance you might need urgent medical attention.

You should seek emergency health care straight away if the person stung:

• Has signs of an anaphylactic reaction.

• Experiences difficulty breathing.

• Develops chest pains.

• Starts having a seizure.

• Vomits.

• Bleeds continuously.

• Develops severe swelling around the sting.

• Loses consciousness.

Sometimes jellyfish stings can become infected. Please see a doctor immediately if you have any of the signs of an infection, such as the wound becoming more painful, more redness, or you develop a fever.

Does pee help a jellyfish sting?

You might have heard that urine can help treat a jellyfish sting. So, to pee or not to pee? Well, this is just a popular myth and Kanani says there is no strong evidence that pee has any benefit.

In fact, studies have shown the opposite.¹ Urine contains compounds like ammonia and urea, which could be helpful on their own if you’ve been stung. However, since pee contains a lot of water, rinsing your sting with it means the ammonia and urea will be too diluted to be of any use.

Research and experts continue to suggest that first aid treatment is the primary concern when dealing with jellyfish stings, and you should be focusing on removing the tentacles from your skin and treating the contacted area to avoid the further release of nematocysts - the thousands of tiny cells on their tentacles.

Responding quickly after a sting can avoid an increase in venom load and potentially save a life.

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How to avoid being stung by a jellyfish

To reduce your chances of being stung by a jellyfish, you can avoid water during jellyfish season from mid-spring through to late summer and early autumn. However, this isn't always possible, especially as summer time is holiday season. So, here are some protective measures you can take when swimming in water where there might be jellyfish:

• Keep an eye out for warning signs on beaches, alerting you to jellyfish or other sea creatures.

• Talk to lifeguards or officials before swimming in open water to make yourself aware of the risks.

• Don’t ever touch a jellyfish, even if you think it is dead.

• Wear a protective wetsuit and something on your feet when swimming in open water.

• Wear sandals when walking in rocky or shallow water.

• Get clued up on how jellyfish move - as they tend to go along with ocean currents.

• Make sure you know what to do if you or someone else is stung.

Further reading

1. To pee, or not to pee?