Jellyfish stings
DEFINITION
Jellyfish stings are relatively common problems for people swimming, wading or diving in seawaters. The long tentacles trailing from the jellyfish body can inject you with venom from thousands of microscopic barbed stingers.
Jellyfish stings vary greatly in severity. Most often they result in immediate pain and red, irritated marks on the skin. Some jellyfish stings may cause more whole-body (systemic) illness. And in rare cases jellyfish stings are life-threatening.
Most jellyfish stings get better with home treatment. Severe reactions require emergency medical care.
CAUSES
Jellyfish tentacles contain microscopic barbed stingers. Each stinger has a tiny bulb that holds venom and a coiled, sharp-tipped tube. The jellyfish uses the venom to protect itself and kill prey.
When you brush against a tentacle, tiny triggers on its surface release the stingers. The tube penetrates the skin and releases venom. It affects the immediate area of contact and may enter the bloodstream.
Jellyfish that have washed up on a beach may still release venomous stingers if touched.
SYMPTOMS
Common signs and symptoms of jellyfish stings include:
- Burning, prickling, stinging pain
- Red, brown or purplish tracks on the skin — a “print” of the tentacles’ contact with your skin
- Itching
- Swelling
- Tingling and numbness
- Throbbing pain that radiates up a leg or an arm
Severe jellyfish stings can affect multiple body systems. These reactions may appear rapidly or several hours after the stings. Signs and symptoms of severe jellyfish stings include:
- Nausea and vomiting
- Headache
- Muscle and joint problems
- Weakness and dizziness
- Fever
- Loss of consciousness
- Difficulty breathing
- Heart problems
The severity of your reaction depends on:
- The type and size of the jellyfish
- Your age, size and health, with severe reactions more likely in children and people in poor health
- How long you were exposed to the stingers
- How much of your skin is affected
When to see a doctor
Seek emergency treatment if:
- Stings cover large areas of skin
- You have severe symptoms or a serious allergic reaction
