The tentacles of jellyfish are covered with microscopic venom-filled nematocysts. When discharged in human skin they create a painful burning sensation. The sting of an Australian box jellyfish may be deadly, but chance encounters with most of the marine animals known as jellyfish (many are unrelated to true jellyfish) are simply unpleasant. Similar to bee stings, allergic reactions to jellyfish are possible and illness can result from extensive stings. Seek emergency medical attention if breathing becomes difficult. Immediate first aid and treatment involves natural home remedies.
Seawater, Sand and Shells
If nothing else is available, rinse the sting with seawater, then cover it with muddy sand and use the edge of a seashell to "shave" the area. This procedure will remove the nematocysts without triggering the release of more venom. Do not touch tentacles with bare hands and do not rub the area. Never initially rinse with fresh water or apply ice or heat as these measures may increase nematocyst firing and additional venom release. Advice from locals may include alcohol, urine or diluted ammonia remedies, but some species will respond unfavorably to these solutions and cause the sting to become worse.
Vinegar
The acetic acid in vinegar stops nematocysts from discharging jellyfish venom; it is the remedy most often used by beach lifeguards. Flood the area or soak it with a vinegar compress for 15 minutes, then use gloves, tweezers or a stick to remove tentacles. Soak the area in vinegar again, or as a follow-up to other treatments. Vinegar can be dabbed on the face, but eyes should only be rinsed with a saline solution. Stings in the mouth can be rinsed with a one-quarter strength solution of vinegar and water. Swish and spit but don't swallow.
Baking Soda
Apply a paste of baking soda; it will prevent nematocysts which have not been activated from discharging their venom. Leave the paste in place for half an hour, or until pain subsides. Scrape the wet paste off with the edge of a credit card. Rinse with saltwater or vinegar and reapply as needed.
Fruit
A paste made from papaya fruit contains enzymes that can be helpful if left in place for 30 minutes. Fresh citrus juice squeezed from lemons or limes contains acetic acid and will have actions similar to vinegar.
Shaving
Shave the affected area using shaving cream or soap lather and a razor. The foam prevents the triggering of venom release by nematocysts, and the razor removes them. Discard the razor after use.
