Jellyfish Sting

What is a Jellyfish Sting?

Jelly fish stings occur frequently. The people at risk for being stung by a jelly fish are those who swim in the ocean, or even wade in ocean water. Jelly fish are difficult to see in water because they are clean in color and have a gelatinous form. Their tentacles trail behind them in the water and are difficult to see as well. However, the tentacles carry venom and are lined with thousands of tiny barbed stingers.

The sting from a jelly fish can be mild to severe in nature. However, if you are stung, it will be immediately evident. The skin around the sting becomes painful and red almost immediately. There will also be visible marks on the skin.

At times, the sting from a jelly fish can cause a fully body reaction and if it is severe enough, the sting can be life threatening. While some stings from jelly fish can be treated at home, others require immediate medical attention.

What are the Symptoms of a Jellyfish Sting?

Symptoms of a jellyfish sting can vary depending on the location and severity of the sting. The symptoms can range from mild to severe, and the treatment will depend on the severity of the injury.

Symptoms include

  • Stinging pain.
  • Burning or prickling pain
  • Tracks on the skin in the shape of the tentacles, can be red, brown, or purple in color.
  • Itching around the site.
  • Inflammation
  • Numbness or tingling in the area
  • A throbbing pain which can radiate along the affected extremity.

Jellyfish stings can be severe. A severe jellyfish sting can affect the organs in the body, or even multiple organ systems. The reactions can appear immediately after the sting, or they can appear several hours after the injury occurs.

Severe symptoms include

  • Nausea
  • Vomiting
  • Muscle weakness
  • Joint problems
  • Dizziness
  • Weakness
  • Fever
  • Sudden difficulty breathing
  • Rapid heart rate
  • Irregular heart rate

The severity of a jellyfish sting is determined by a number of factors.

Severity factors

  • The breed and size of the jellyfish.
  • The age of the person stung.
  • The health of the patient stung.
  • The size of the person stung.
  • How long the stingers remained in the skin.
  • How large the sting is and how much skin was affected by the sting.

Jellyfish Sting Causes

Jellyfish have cells on their tentacles called cnidocytes. These cells contain venom-containing spines called nematocysts, which the jellyfish uses to protect itself. When the tentacles touch you, the nematocysts shoot out these spines within a fraction of a second. They can easily pierce human skin, and the venom is injected into the body.

Jellyfish venom contains a class of protein called porins. These are so named because they act as a pore across a cellular membrane. This creates a hole in the cells of your body so that the venom can enter and damage the cell. The venom is indiscriminate and will attack any cells it comes across, including skin cells, blood cells, and nerve cells. However, the venom of different species of jellyfish contains different combinations of these porins, which is why the intensity and danger of a jellyfish sting varies from species to species.

How is a Jellyfish Sting Treated?

The majority of jellyfish stings can be treated at home. The area should be thoroughly rinsed with salt water. After rinsing, you should apply a baking soda paste or vinegar. Taking an over the counter pain medication will help reduce the swelling and relive the pain from the sting.

There are other situations that may require a doctor to write a prescription for the person who was stung. Oral antihistamines may be prescribed for someone who develops a rash as reaction to the sting. Corticosteroids may be required for those who have a mild allergic reaction.

A jellyfish sting that is on or near the eye may require you to receive medical treatment to flush the venom out. You may also require pain medication to control the burning and pain associated with the sting.

For someone having a severe reaction to a jellyfish sting, emergency care is necessary. A person who is affected by a severe jellyfish sting may require the following treatment:

  • CPR
  • Life support for unstable, or erratic breathing, heart rate, or high blood pressure
  • Antivenin medication.
  • Prescription medication for pain

Jellyfish Sting Prevention

If you are planning to swim in the sea, either on the beach or in open waters, always check if that area is inhabited by jellyfish. Most species of jellyfish prefer warmer waters, including the sea nettle, the Portuguese man-of-war, and the box jellyfish, which has a particularly painful and potentially deadly sting. However, some species prefer cooler water, including the Lion’s mane, which can grow to sizes of one meter in diameter.

Not only is it prudent to check for jellyfish before swimming, you should avoid or take extreme care on beaches where jellyfish have washed up. Even dead jellyfish can still sting, as can tentacles that have been detached from the body.

If you must swim or dive in areas inhabited by jellyfish, be sure to wear protective clothing specifically designed to offer protection against jellyfish stings. This type of clothing is a little thicker than normal swimwear to prevent the nematocysts from penetrating it.

Last Reviewed:
October 06, 2016
Last Updated:
March 14, 2018