Jellyfish are sea creatures that have a nearly see-through (transparent) body with long finger-like structures called tentacles. Stinging cells inside the tentacles can hurt you if you come in contact with them. Some stings can cause serious harm.

Jellyfish venom

Types of jellyfish include:

• Lion's mane (Cyanea capillata)
• Portuguese man-of-war (Physalia physalis)
• Sea nettle (Chrysaora quinquecirrha), one of the most common jellyfish found along the Atlantic and Gulf Coasts
• Sea wasp (Chironex fleckeri, Chiropsalmus quadrigatus), found near the coasts of northern Australia and the Philippines

Note: This list is not all inclusive.

Portuguese man-of-war:

• Abdominal pain
• Changes in pulse
• Chest pain
• Headache
• Muscle pain and muscle spasms
• Numbness and weakness
• Pain in the arms or legs
• Raised red spot where stung
• Runny nose and watery eyes
• Swallowing difficulty
• Sweating

Sea wasp:

• Breathing trouble
• Nausea and vomiting
• Severe pain and swelling
• Slow heart beat
• Skin tissue death

Lion's mane:

• Breathing trouble
• Muscle cramps
• Skin burning and blistering (severe)

Sea nettle

• Mild skin rash (with mild stings)
• Muscle cramps and breathing trouble (with extensive contact)

Seek immediate medical attention. Death can occur within minutes with sea wasp and lion's mane stings.

If you know for certain that the person has been stung by a Portuguese man-of-war or sea nettle, wash with salt water (ocean water is OK, but make sure you do NOT get sand in the wound). Protect affected area if possible. Soak the area with a solution made of 1/2 vinegar and 1/2 water for about 30 minutes. This helps remove the tentacles. Rinse the area and then resoak with more 1/2 strength vinegar.

(You may also remove tentacles by applying a paste made of flour or shaving cream and scraping the area with a dull instrument such as a credit card.)

Apply a cream containing a painkiller, an antihistamine, or a corticosteroid.

Determine the following information:

• Patient's age, weight, and condition
• Name of the marine animal if possible
• Time stung

The National Poison Control Center (1-800-222-1222) can be called from anywhere in the United States. This national hotline number will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

See: Poison control center - emergency number

The health care provider will measure and monitor the patient's vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated as appropriate. The patient may receive:

• Breathing assistance
• Antiserum (for sea wasp stings)

Portuguese man-of-war and sea nettle stings are rarely deadly. Sea wasp stings can be deadly in minutes.

Marx J. Rosen's Emergency Medicine: Concepts and Clinical Practice. 6th ed. St. Louis, Mo: Mosby; 2006.

Noble J. Textbook of Primary Care Medicine. 3rd ed. St. Louis, Mo: Mosby; 2001.