Marine Stings and Scrapes

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Marine Stings and Scrapes

Topic Overview

Walking on a beach or swimming in the ocean can be fun and relaxing. But just like any other activities, accidents can happen. This topic will help you determine the next steps to take if you have a jellyfish or Portuguese man-of-war sting, seabather's eruption, or a coral scrape.


Jellyfish and Portuguese man-of-wars are members of a large group of venomous marine animals that also includes fire coral and sea anemones. They are present all over the world and cause injury and illness through the release of venom when their tentacles come in contact with skin (stinging). Tentacles are long, slender, flexible growths found on jellyfish, Portuguese man-of-wars, squid, and octopuses. Tentacles are used for grasping, feeling, moving, and killing prey by stinging. While the sting of a jellyfish or Portuguese man-of-war can cause severe illness and extreme pain, documented deaths are rare.

Jellyfish are often present in coastal waters, having been brought ashore by winds or ocean currents. They are most common in warm ocean waters, especially along the Atlantic coast of the United States. Stings result from contact with the tentacles, which trail from the jellyfish's see-through body. Jellyfish swimming in the water are often hard to see. Beached jellyfish, which may look like the cellophane wrapper from a cigarette pack, can sting if touched.

Jellyfish stings cause immediate, intense pain and burning that can last for several hours. Raised, red welts develop along the site of the sting, which may look like you have been hit with a whip. The welts may last for 1 to 2 weeks, and itchy skin rashes may appear 1 to 4 weeks after the sting. Fortunately, most jellyfish stings are not severe. Extensive stings, allergic reactions, or severe reactions are not common but do occur. To avoid the risk of drowning, swimmers should get out of the water as soon as they realize they have been stung.

The box jellyfish, which is found in the Indian Ocean and South Pacific, can cause a fatal reaction. It is the only jellyfish for which a specific antidote (antivenin) exists. If you get this antivenin, it may save your life.

Seabather's eruption is a rash that develops from the stings of jellyfish or sea anemone larvae. The rash can be quite itchy and annoying, but it usually goes away without medical treatment in 10 to 14 days.

Portuguese man-of-wars (hydrozoans) live in warm seas throughout the world but are most common in the tropical and subtropical regions of the Pacific and Indian oceans and in the Gulf Stream of the North Atlantic Ocean. They float on the surface of the water with their long, stinging tentacles trailing in the water below. Detached tentacles that wash up on the beach may remain dangerous for months.

Portuguese man-of-war stings produce immediate burning pain and redness where the tentacles touched the skin. The affected area develops a red line with small white lesions. In severe cases, blisters and welts that look like a string of beads may appear. Stings that involve the eye may cause pain, swelling, excessive tears, blurred vision, or increased sensitivity to light. Severe reactions are most likely to occur in children and small adults. Severe toxic reactions to the venom can also occur.

Coral scrapes

Coral scrapes and cuts are common injuries that may occur when you walk on a beach or swim, snorkel, or dive in warm water. Coral polyps, the soft living material that covers the surface of coral, can be easily torn away from the rigid and abrasive structure underneath if you touch, bump, or fall on coral. A skin infection may develop when small pieces of coral, other debris, and bacteria get inside the wound. Scrapes and cuts from sharp-edged coral may take weeks or even months to heal.

Check your symptoms to decide if and when you should see a doctor.

Check Your Symptoms

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Home Treatment

Home treatment can help ease your discomfort and prevent other problems.

Jellyfish and Portuguese man-of-war stings

  • Do not rub the tentacles with your hands, a towel, sand, or clothing.
  • Soak a compress in household vinegar (5% acetic acid solution) and hot water. Apply to the affected area to prevent further stings.
  • If vinegar is not available, rinse the area with large amounts of salt water. Do not use fresh water—this may cause the tentacles to release venom. Do not use urine, gasoline, kerosene, or turpentine.
  • Rinse eye stings with a saline solution, such as Artificial Tears. Do not put vinegar, alcohol, or any other "stinger solution" in the eyes. The skin around the eye can be dabbed with a cloth soaked in vinegar, but you must be extremely careful not to get any of the solution in the eye.
  • If vinegar is not available, unseasoned meat tenderizer, baking soda, or one-quarter-strength household ammonia may be useful for treating jellyfish stings. Be careful not to get these products in your eyes. Meat tenderizer or baking soda may be sprinkled directly onto the affected area or made into a paste by adding water and then applied to the skin. Apply meat tenderizer to the skin for no longer than 15 minutes. Soak a cloth in ¼ cup (60 mL) ammonia mixed with ¾ cup (180 mL) water and put it on the affected area.
  • After decontamination, pick off tentacles with a stick or your hand protected by a towel or glove. Be very careful not to rub or press the tentacles.
  • If it is available, apply a lather of shaving cream or soap, or a paste of baking soda, flour, or talc to the skin. The stinging cells will stick to the shaving cream or paste and can then be easily scraped off with a safety razor, a knife edge, or the edge of a credit card.
  • Take an antihistamine, such as diphenhydramine or chlorpheniramine, or apply 1% hydrocortisone cream to help control itching. Note: Do not use the cream on children younger than age 2 unless your doctor tells you to. Do not use in the rectal or vaginal area in children younger than age 12 unless your doctor tells you to. Also, don't give antihistamines to your child unless you've checked with the doctor first.
  • Use an ice pack to help relieve pain.
  • Clean any open sores 3 times per day, apply an antiseptic ointment, such as bacitracin, and cover with a light bandage.

Seabather's eruption

  • Do not rub your skin. If larvae are on your skin, rubbing will cause them to sting.
  • Remove your swimsuit as soon as possible. Since larvae can become trapped in the fabric of your suit, it is important to remove a contaminated suit to prevent more stings.
  • If available, rinse in household vinegar (5% acetic acid solution) or rubbing alcohol (40%–70% isopropyl alcohol).
  • Shower with fresh water. Apply soap and vigorously scrub your skin. Do not shower with a contaminated suit on. If larvae are trapped in the fabric of a suit, a freshwater shower will cause the larvae to sting.
  • Take an antihistamine, such as diphenhydramine or chlorpheniramine, or apply 1% hydrocortisone cream cream to help control itching. Note: Do not use the cream on children younger than age 2 unless your doctor tells you to. Do not use in the rectal or vaginal area in children younger than age 12 unless your doctor tells you to. Also, don't give antihistamines to your child unless you've checked with the doctor first.
  • Use an ice pack to help relieve pain.
  • Wash the rash with soap and water daily.

Coral scrapes and cuts

Most minor coral scrapes or cuts can be treated at home.

  • Wash the wound for 5 minutes with a soft brush or towel and large amounts of warm water and soap (mild dishwashing soap, such as Ivory, works well). Cleaning the wound as soon as possible may reduce the risk of infection, scarring, and tattooing of the skin from coral material left in the wound. See how to clean a wound.
  • After washing, rinse the wound with a large amount of fresh water.
  • After rinsing with fresh water, rinse the wound again with a solution of one-half hydrogen peroxide and one-half water.
  • After rinsing with a solution of one-half hydrogen peroxide and one-half water, rinse again with fresh water.
  • Stop mild bleeding with direct pressure to the wound. See how to stop bleeding.
  • Use an antibiotic ointment, such as polymyxin B sulfate (for example, Polysporin) or bacitracin. Put the ointment lightly on the wound. The ointment will keep a bandage from sticking to the wound. Be sure to read the product label about skin sensitivity. If a skin rash or itching under the bandage develops, stop using the ointment. The rash may mean you had an allergic reaction to the ointment. Antibiotic ointments that contain neomycin may have an increased risk of causing an allergic reaction.
  • Consider bandaging the wound. You may need to protect your wound from getting dirty or irritated. If available, use a nonstick dressing. Be sure to read the product label for correct use.
    • Clean the wound thoroughly before bandaging it to reduce the risk of infection occurring under the bandage.
    • Apply a clean bandage when it gets wet or soiled to further help prevent infection.
    • If a bandage is stuck to a scab, soak it in warm water to soften the scab and make the bandage easier to remove.
  • Watch for symptoms of a skin infection.
  • Be patient. Coral scrapes and cuts may take weeks and sometimes even months to heal completely.
Medicine you can buy without a prescription
Try a nonprescription medicine to help treat your fever or pain:

Talk to your child’s doctor before switching back and forth between doses of acetaminophen and ibuprofen. When you switch between two medicines, there is a chance your child will get too much medicine.

Safety tips
Be sure to follow these safety tips when you use a nonprescription medicine:
  • Carefully read and follow all directions on the medicine bottle and box.
  • Do not take more than the recommended dose.
  • Do not take a medicine if you have had an allergic reaction to it in the past.
  • If you have been told to avoid a medicine, call your doctor before you take it.
  • If you are or could be pregnant, do not take any medicine other than acetaminophen unless your doctor has told you to.
  • Do not give aspirin to anyone younger than age 20 unless your doctor tells you to.

Symptoms to watch for during home treatment

Call your doctor if any of the following occur during home treatment:

  • The lips, tongue, or throat become swollen, or other severe symptoms develop.
  • Symptoms of a skin infection develop.
  • A rash develops.
  • Symptoms become more severe or frequent.


You can limit your risk of being injured by jellyfish, a Portuguese man-of-war, or coral.

  • Be familiar with the marine risks in the area where you plan to swim, snorkel, or dive. If you are traveling, obtain information about the local conditions.
  • Be prepared with first aid supplies that might be needed for a injury.
  • Watch for warning signs that are posted when there is a jellyfish or Portuguese man-of-war invasion.
  • Do not touch jellyfish, Portuguese man-of-wars, or coral.
  • Watch out for jellyfish and Portuguese man-of-wars in the water, particularly when there are strong onshore winds.
  • Stay out of the water when jellyfish and Portuguese man-of-wars are present. Look out for the bluish floats of the Portuguese man-of-war, and avoid the poisonous trailing tentacles.
  • Watch for beached jellyfish and Portuguese man-of-wars. Their tentacles may still sting.
  • Do not rely on clothing or on coating the skin with petroleum jelly (such as Vaseline) to prevent stings. Wear a wet suit to reduce your risk of getting stung. A wet suit is a close-fitting, one- or two-piece suit, usually made of rubber or foam neoprene. Swimmers, snorkelers, divers, kayakers, and other people who spend time in cold water may wear wet suits for warmth and protection.
  • Wear protective shoes when walking on the beach. Avoid stepping on marine life.
  • Avoid swimming or snorkeling in swallow water, where touching or bumping into coral might occur.
  • Wash your swimsuit with detergent and heat-dry after use. This will kill the stinging larvae that cause seabather's eruption.
  • Talk to your doctor about carrying an allergy kit if you have had any sort of allergic reaction or severe reaction to a marine sting in the past.
  • Consider using a topical jellyfish sting inhibitor lotion, such as Safe Sea.

Preparing For Your Appointment

To prepare for your appointment, see the topic Making the Most of Your Appointment.

You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:

  • What are your main symptoms?
  • When did your symptoms begin? How have your symptoms developed, progressed, or changed since the sting?
  • Do you know what you were stung by? Can you describe what stung you? Note: Bring a sample of the stinging organism with you if you can safely do so. A sample may help your doctor plan your treatment.
  • When were you stung? How many times were you stung?
  • Where were you when you were stung?
  • Have you ever had an allergic reaction or a severe reaction to a similar sting?
  • What steps have you tried at home to take care of this problem? Did they help?
  • Do you have any health risks?


ByHealthwise Staff
Primary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency Medicine
Specialist Medical ReviewerDavid Messenger, MD
Last RevisedMay 20, 2011

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