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, sometimes painful rash. If more severe this rash may blister, 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 types of jellyfish are harmless to humans, In the UK many jelly fish stings are more like getting stung by nettles and cause a similar tingly rash. The types of jelly fish in the UK waters which cause more intense stings are the lion's mane and the mauve stinger which can give electric shock like stings. Whilst still rare, the Portuguese man o'war is being found more frequently on the West Coast of the UK

Other types of jellyfish which can give a more severe sting include:

• Box jellyfish - found in the Pacific and Indian oceans.

• Bluebottle jellyfish - found in warmer seas.

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

• 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.

In rare cases some people who have been stung may have a severe allergic reaction (anaphylaxis) and will require emergency care. Symptoms can include:

• Shock.

• Severe pain.

• Swelling of the lips, tongue, mouth, throat, neck, ears, eyelids, palms, or soles of the feet.

• Difficulty breathing.
  

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.

Jellyfish sting treatment

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.

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 should not pee on a jellyfish sting. This is just a myth and Kanani says there is no evidence that pee has any benefit.

In fact, studies have shown the opposite.¹ Your pee 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.

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.

Patient picks for Stings and bites

Skin, nail and hair health

What to do if you're stung by a sea urchin

While many sea urchin stings can be mild and their symptoms go away within a few days, there is a possibility of them becoming seriously infected. Therefore, it's important to know how to act in these situations and when to seek professional help.

by Emily Jane Bashforth

Skin, nail and hair health

Jellyfish sting

Jellyfish are common sea creatures and many of them sting. Most jellyfish stings are not harmful. Jellyfish species in the UK are generally not dangerous, although stings from the Portuguese man o' war, Lion's mane jellyfish and compass jellyfish can be painful and, if stung many times, harmful. It is also possible to have an allergic reaction to any jellyfish sting.

by Dr Hayley Willacy, FRCGP

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?