The transparent body and long, thin tentacles of a jellyfish are difficult to avoid while swimming. Inhabitants of oceans worldwide, jellyfish usually swim in groups and can be swept ashore by storms. Two types, the sea nettle, or Chrysaora quinquecirrha, and the Portuguese man-of-war, or bluebottle jellyfish, are common in North America. The very poisonous box jellyfish are found in Hawaii. Nematocysts, stinging cells attached to the tentacles, stun prey and inflict pain on humans who come in contact with them. Even tentacles that break off when the animal is injured can inflict stings.
Rinses
Home remedies are sufficient to treat most jellyfish encounters. Seek immediate medical care for serious reactions such as difficulty breathing, chest pain, confusion or blistering skin. According to researchers at the University of California, these and other reactions, such as headache or abdominal pain, may occur within five minutes to several hours after exposure. When a jellyfish sting occurs, it may be tempting to find a shower on the beach and rinse off. However, using fresh, tap or bottled water can stimulate the nemocysts to release additional venom. Salty sea water is easily available and is the ideal rinse. Tentacles need to be removed carefully, using whatever plastic or natural implements are available, without causing more stings. A vinegar rinse, full or half strength, may neutralize any remaining nemocysts. The Mayo Clinic cautions against using vinegar on Chesapeake Bay sea nettle stings, however.
Pastes
Similar to bee stings, jellyfish leave barbs in the skin that may hold additional venom. It is inadvisable to rub the affected area, because squashing the barbs can make the sting worse. Instead, apply shaving cream, a paste of baking soda and sea water, or even wet sand, and use an implement with a thin edge to scrape the skin clear, using a shaving motion. A credit card or sea shell can work well. The Mayo Clinic states that minor skin irritations typically resolve in 7 to 14 days, with some marks remaining for up to two months.
Heat and Cold Packs
Pain relief may be obtained by immersing the affected area in hot water. Take care not to scald the skin; temperatures between 110F and 113F are recommended by the Mayo Clinic. Gradually increase the heat until water temperature is as high as can be tolerated. Ice packs may also reduce pain and inflammation. Itching generally responds to antihistamine medication, topical corticosteroid cream or calamine lotion.
