From time to time, someone will get “hit” by a jellyfish. We hope this doesn’t happen to you, but if it does, this information from the Mayo Clinic may be helpful. Please note that we have been stung by a jellyfish only once or twice on Vieques, and we swim almost every day when we are here.
Treatments and Drugs
Most jellyfish stings can be treated by rinsing the area with salt water, applying vinegar or a baking soda paste, and taking an analgesic.
Someone having a severe reaction to a jellyfish sting may need emergency care, including:
Cardiopulmonary resuscitation (CPR).
Life support to stabilize breathing, heart rate, and blood pressure.
Antivenin medication, if the sting is from a box jellyfish.
Pain medicine.
Other Medical Treatments
Other circumstances also may require doctor-supervised treatment:
A rash or other skin reaction due to delayed hypersensitivity may be treated with oral antihistamines or corticosteroids.
A jellyfish sting occurring on or near an eye requires immediate medical care for pain control and good eye flushing. You will likely be seen by a doctor specializing in eye care (ophthalmologist).
Lifestyle and Home Remedies
The best treatment for you may depend on the type of jellyfish that stung you. But most stings can be treated with these simple remedies:
Remove stingers. Remove any pieces of jellyfish tentacle in your skin by rinsing the wound with seawater. You can also try gently scraping off the stingers with the edge of an ID card or a credit card. Avoid getting sand on the wound. Don’t rinse with freshwater or rub the area with a towel, as these actions may activate more stingers.
Rinse with vinegar or apply a baking soda paste. Rinse the affected area with vinegar for about 30 seconds. Or apply a paste of baking soda and seawater. Each method may deactivate the stingers of certain jellyfish species.
Take a hot shower or apply ice packs. Hot water— no hotter than you can tolerate, but not above 113°F (45°C)— and ice packs may help relieve pain.
Take an analgesic and apply calamine lotion or lidocaine to relieve itching and discomfort.
Remedies to Avoid
These remedies are unhelpful or unproven:
Human urine
Meat tenderizer
Pressure bandages
Solvents, such as formalin, ethanol, and gasoline
Prevention
The following tips can help you avoid jellyfish stings:
Wear a protective suit. When swimming or diving in areas where jellyfish stings are possible, wear a wetsuit or other protective clothing. Diving stores sell protective “skin suits” or “stinger suits” made of thin, high-tech fabric.
Get information about conditions. Consult local residents or officials at the local health department before swimming or diving in coastal waters, especially in areas where jellyfish are common.
Avoid the water during jellyfish season. Stay out of the water when jellyfish numbers are high.
Be careful where you dive. To avoid stings on the face, don’t dive into waters that may have jellyfish.
Use protective lotions. Some clinical evidence suggests that lotions such as Safe Sea may reduce stinging after exposure to jellyfish tentacles.
Leave the water calmly. If you’re stung, get out of the water without splashing much. This helps prevent more stingers from releasing venom.
http://www.mayoclinic.org/diseases-conditions/jellyfish-stings/basics/treatment/con-20034045