Ocean currents, winds and their own biological cycles cause jellyfish to approach coastal areas, although on our beaches We found no deadly jellyfish stings, it is clear that their presence would make any bather’s holiday, day off or free time unpleasant.therefore It’s handy to have the information you need to protect yourself from this uncomfortable animalknow what we can do if bitten by it, and even know how to equip our beach first aid kit so that we have what is necessary when treating injuries on the beach.
Although there is no consensus among experts on whether an increased presence on the Spanish coast could be achieved, Fundación iO, a scientific organization dedicated to the study of infectious diseases, emerging zoonotic diseases, and tropical and travel medicine, estimates that, Several factors combine to favor jellyfish reproduction Examples include the entry of organic pollutants (especially agricultural fertilizers) into the ocean and overfishing, which reduces the competition of jellyfish for food while reducing the number of their predators.
Signs of a jellyfish sting
what is reality Over 200 species of jellyfish inhabit our coastlines. The most dominant jellyfish in our waters are Pelagia noctiluca (also known as the carnation jellyfish) and Rhizostoma pulmo (known as aguamala).
The stinging cells of jellyfish can inject venom through tentacle contact.which contain tiny spines that penetrate our skin or body. “Their bites are very painful and produce red, eyelash-like lesions with blisters that can scar for life.”María del Campo, Deputy Secretary General of the Spanish Society of Family and Community Medicine (semFYC), explains. “The most common are rash-like skin lesions (hives or blisters) with intense itching, and, after multiple bites from a single bite, may also cause hives (generalized urticaria),” says allergist Javier Pepe Leila added at the Vall d’Hebron Hospital in Barcelona.
Recently, the Spanish Society of Allergology and Clinical Immunology (Seaic) warned that, An allergic reaction may occur and other symptoms such as nausea, vomiting, diarrhea, stomach cramps, cramps, muscle pain, fever, chills, headache, dizziness, and shortness of breath may occur.
In this sense, Javier Pereira points out that repeated jellyfish stings may produce an anaphylaxis or anaphylactoid reaction in susceptible individuals, “an immediate systemic reaction similar to anaphylaxis, but not caused by caused by an IgE-type immune response”. Pereira believes more research is necessary to better understand the underlying immune components of jellyfish and to elucidate their role in sensitization.
What to do if you get stung by a jellyfish
As for how we should act, understand the situation first.There is an app (MedusApp) that is one of the most downloaded jellyfish viewing apps in the worldwhich allows anyone to be warned of the presence of jellyfish and provide a real-time map of where they were detected.
The golden rule is Listen to beach monitoring and emergency services. If the beach is closed, we should not swim even if the jellyfish are invisible to the naked eye. “The best way to prevent bites is to follow the warnings of these services,” Pereira emphasizes.
The iO Foundation warns of particular concern for children, people with a history of allergies, previous stings and people with heart conditions. It is also recommended to avoid areas where many boats are docked, as their propellers can snap off tentacles, and many stings are caused by unseen loose tentacles.
If we are stung, You must get out of the water quickly and do not rub the affected area with sand or a towel. Next is to carefully remove the tentacles that are still attached to the skin with tweezers or protective gloves. The area should be flushed with copious amounts of seawater or saline. “Fresh water and alcohol help expel the venom from the tentacles.’, warned Maria del Campo, Who recommends a cold compress for about 15 minutes without rubbing (If we use ice cubes, it is necessary to avoid direct contact with the skin with the cloth) Then soak the compress with vinegar or reduced bicarbonate.
Regarding whether to recommend topical antihistamines and corticosteroids, Pereira believes Antihistamines (one or two doses per day) and methylprednisolone 0.1% (a topical corticosteroid) can be used if itching persists. The allergist rejects and warns against false myths such as the use of human urine, alcohol or ammonia, bandages and pressure immobilization.
when to see a doctor
You should go to a hospital or health center if you Nausea, vomiting, diarrhea, stomach cramps, cramping, muscle pain, fever, chills, headache, dizziness, increased pain or swelling, itching all over the bodyhave purulent in injury and Shortness of breathA doctor should also be consulted when an eye, ear or mouth is bitten.
Generally, symptoms improve after 24 hours, Pereira said. It is important to note that the size of the lesion should be reduced and the skin should not become red or very hot. Allergists stress against scratching to avoid bacterial superinfection of the skin (cellulitis): “Taking antihistamines for itching is better than scratching.”
emergency kit in beach bag
With these recommendations in mind, our bags on the beach, especially if we are in an area where jellyfish are frequent, Should include an emergency kit with tweezers, antihistamines, and topical corticosteroids.
Seaic recommends that whenever possible Identify the jellyfish causing the sting so health care professionals who manage the case can be notified. Likewise, it urges people to report all jellyfish stings and exposures on our shores via the MedusApp, and not to underestimate the problem.
The scientific society recalled that in 2026, a severe allergic reaction to a nomadic jellyfish sting occurred off the coast of Tel Aviv, Israel; in 2018, the Marine Asthma Committee published a case of anaphylaxis due to nocturnal jellyfish.