Information on symptoms, first care and prevention measures against jellyfish injuries
Contact with jellyfish is a relatively common incident on beaches, especially during the summer in regions such as the coast of Santa Catarina. The resulting injury, popularly known as “burn”, is actually poisoning caused by contact with the animal’s tentacles. This article offers general and factual information about what these injuries are, their most common symptoms and the first care measures recommended by health authorities. The content is strictly informative and does not replace the assessment of a healthcare professional.
What is a jellyfish injury?
The injury caused by a jellyfish is not a thermal burn, but rather poisoning. The tentacles of these marine animals have specialized cells called cnidocytes. When touched, these cells fire tiny, needle-like structures that inject a toxic substance (venom) into the victim’s skin.
This reaction is an animal’s defense and hunting mechanism. Even if the jellyfish is in the sand or its tentacles are fragmented in the water, the cnidocytes can remain active and capable of injecting the venom upon simple contact.
Common symptoms after contact
The intensity of symptoms can vary depending on the species of jellyfish, the area of contact with the skin and the person’s sensitivity. Most cases are mild, but the pain can be severe. The most common signs and symptoms manifest locally and include:
- Immediate pain, with a stinging, burning or stinging sensation.
- Red, linear marks on the skin, which may form a tentacle-like pattern.
- Swelling (edema) in the affected area.
- Intense itching.
In rarer situations, systemic reactions may occur, which affect the body more broadly. Symptoms such as nausea, vomiting, headache, muscle cramps or difficulty breathing require emergency medical attention.
First care and prevention measures
Knowing how to act after contact with a jellyfish is essential to alleviate pain and avoid complications. General first aid guidelines are focused on inactivating the venom and removing the tentacles attached to the skin.
What to do
- Get out of the water: When you feel contact, exit the water calmly to avoid further accidents.
- Wash with sea water: Wash the affected area exclusively with sea water, without rubbing. Seawater helps remove tentacles without activating more cnidocytes.
- Apply vinegar: Common vinegar (acetic acid) is widely recommended to neutralize the venom of most species found on the Brazilian coast. Soak a clean gauze or cloth in vinegar and apply it to the injury for about 10 to 30 minutes.
- Remove the tentacles: If tentacles are visible, carefully remove them with tweezers or the edge of a credit card. Never use your bare hands.
What NOT to do
- Do not use fresh water: Fresh water (from a tap, bottle or shower) can worsen the injury, as the change in osmolarity causes cnidocytes that are still intact to fire more venom.
- Do not rub the area: Rubbing the area with sand, towels or any other object can increase the release of the toxin.
- Do not apply urine or alcohol: These popular practices are ineffective and can further irritate the skin.
Prevention
- Check lifeguard warnings or beach signs about the presence of jellyfish.
- Avoid entering the sea in areas with a high concentration of these animals.
- Don’t touch jellyfish, even if they appear dead in the sand.
The information presented serves as a general first care guide. Jellyfish injury, although generally of low severity, can cause severe pain and, in rare cases, severe allergic or systemic reactions. This article is for informational purposes only and does not replace a medical consultation. If symptoms are severe, persistent, or if the affected area is very large, seek medical attention or a lifeguard station immediately.
