29 July 2026
The purple jellyfish (Pelagia noctiluca) is one of the most common and painful species bathers encounter in Greek and Mediterranean waters during the summer.
Jellyfish do not attack people, but they sting on contact. Their tentacles contain specialised cells that release venom, causing symptoms that range from mild irritation to, in rare cases, severe allergic reactions.
What is the purple jellyfish?
Among Mediterranean species, the purple jellyfish is considered one of the most painful. Together with the nomadic jellyfish, it is responsible for many of the more intense sting reactions reported in Greek seas.
Common symptoms
Most stings are not dangerous and symptoms usually improve within a few days. Typical reactions include:
- Intense burning, stinging and pain at the contact site
- Red, brown or purple marks that follow the shape of the tentacles
- Itching that can last several days
- Local swelling
- Pain that may spread along an arm or leg
More serious symptoms
In some cases, systemic reactions can occur, including:
- Nausea and vomiting
- Headache
- Muscle pain or cramps
- Severe weakness or dizziness
- Difficulty breathing
- Heart rhythm disturbances
- Anaphylactic reaction (rare but life-threatening)
Anaphylaxis requires immediate emergency medical care.
What affects the severity of a sting?
The intensity of the reaction depends on several factors:
- The type and size of the jellyfish
- How long the tentacles remained in contact with the skin
- The part of the body affected
- The person’s age (children often react more strongly)
First aid for purple jellyfish stings
Most cases can be managed without hospital treatment by following these steps:
- Rinse the area with seawater only. Do not use fresh water.
- Do not rub the skin, as this can release more venom.
- Carefully remove any remaining tentacles using tweezers, gloves or a plastic card.
- For purple jellyfish, rinse only with seawater or a 1:1 mixture of seawater and baking soda. Vinegar is not recommended, as it may trigger more stinging cells.
- Apply ice (wrapped) to reduce pain and swelling.
- For itching or redness, calamine lotion or a mild cortisone cream may help (follow medical advice).
- Pain can be relieved with common analgesics such as paracetamol or ibuprofen.
When to seek urgent medical help
Go to hospital or call emergency services immediately if any of the following develop:
- Swelling of the lips, face or eyes
- Difficulty breathing or swallowing
- Hoarseness
- Fainting or severe dizziness
- A widespread rash covering large areas of the body
How to reduce the risk
Experts advise:
- Check with lifeguards whether jellyfish have been sighted
- Avoid touching jellyfish that have washed ashore — they can still sting
- Keep a safe distance from tentacles in the water
- Consider protective clothing or equipment when diving or doing water sports in known jellyfish areas
Most purple jellyfish stings are mild and resolve with simple first aid. Prompt and correct treatment significantly reduces pain and lowers the risk of complications.