### Jellyfish Stings and Their Effects on Human Skin Jellyfish are fascinating marine creatures known for their bell-shaped, gelatinous bodies and long tentacles. Some jellyfish species have stingers called nematocysts, which can pierce human skin and inject venom. These stings can cause various reactions on the skin, ranging from mild irritation to severe pain. #### What Happens When a Jellyfish Stings? When a jellyfish stings, its nematocysts release venom into the skin. This venom can cause red, painful welts at the site of contact. The severity of the reaction depends on the type of jellyfish and the individual's sensitivity to the venom. Some people may experience mild itching and redness, while others might suffer from intense pain and swelling. #### Potential Allergic Reactions Jellyfish venom contains various substances that can trigger allergic reactions in some individuals. Symptoms of an allergic reaction may include hives, difficulty breathing, and swelling of the face or throat. In severe cases, anaphylaxis can occur, which is a life-threatening condition requiring immediate medical attention. #### Geographic Distribution of Harmful Jellyfish Harmful jellyfish species are found worldwide, but the most toxic ones are typically located in the Indo-Pacific and Australian waters. These regions are home to some of the most dangerous jellyfish, such as the box jellyfish and the Portuguese man-of-war. #### First Aid for Jellyfish Stings If stung by a jellyfish, it is essential to act quickly. Rinse the affected area with vinegar to neutralize the venom. Avoid using fresh water, as it can activate more nematocysts. Remove any tentacles carefully using tweezers or the edge of a credit card. Afterward, immerse the area in hot water (not scalding) to help reduce pain. Seek medical attention if symptoms worsen or if an allergic reaction occurs.