Jellyfish Stings: Signs, Symptoms, First Aid, Treatment, Prevention

For those of us who like to enjoy swimming, diving or simply just wading in the sea, a sting from a jellyfish, unfortunately, is quite a common occurrence. A single jelly fish has lengthy tentacles coming out from its body and they have the capacity to inject venom from thousands of its microscopic barbed stingers. The stings from a jellyfish vary a lot in terms of their severity. People bitten by a jelly fish often experience immediate pain, redness and irritated marks on the skin. There are some jellyfish stings which can cause symptoms all over the body. Prompt medical attention is required for severe reaction to a jellyfish sting. In rare cases, jellyfish stings can also be life-threatening. The good news is, most of the times conservative or home treatment is sufficient to treat a jellyfish sting.

Jellyfish Stings

What Exactly Is A Jellyfish?

Jellyfishes are marine or sea animal belonging to the group Cnidaria. Jelly fishes are gelatinous sea animals that are not aggressive by nature and are found to be swimming freely in the sea. Their body is surrounded by tentacles. These tentacles contain sacs, also known as nematocysts, which are filled with venom and which causes the sting. The jellyfish sting can be painful and can sometimes be also fatal.

Where Are Jellyfish Located?

Jellyfishes are found all over the world, but the most poisonous of them are found in the Australian and Indo-Pacific waters. Jellyfish are commonly found near the water’s surface at the times when the light is fading. They can be found washed up on the beach or floating in the water column. Stings occurring from jellyfish are mostly accidental in nature, such as while swimming, stepping on them or accidentally touching them. There are certain times when the jellyfish have reproductive gatherings about a week to 10 days after a full moon. So, you can find an increased number of jellyfish at this time.

Mechanism of Jellyfish Sting

The tentacles of Jellyfish contain microscopic barbed stingers. There is a tiny bulb present in each stinger, which contains venom along with a sharp-tipped coiled tube. The venom is used by the jellyfish to protect itself and to kill prey. When a person accidentally brushes against a tentacle, the tiny triggers present on its surface eject barbs, which are known as stingers. Its tube pierces the skin and releases the venom. The venom affects the surrounding region of contact and can also enter the bloodstream. Jellyfish, which have been washed up on a beach still can release poisonous stingers when they are touched.

Harmful/Lethal Types of Jellyfish

There are many types of jellyfish whose sting are harmless to humans and the symptoms can be relieved with home treatment or conservative management. However, there are some types of jellyfish whose sting can result in severe pain and can also cause systemic symptoms. Some of the jellyfish whose sting can cause serious problems in people, are:

  • Box Jellyfish: Also known as sea wasps, sting by this type of jelly fish can cause acute pain and fatal reactions, although this is rare. Species of Box Jellyfish, which are more dangerous, are found in the warm waters of the Indian and Pacific oceans.
  • Portuguese Man-of-War: Also known as Bluebottle Jellyfish, this type of jellyfish mostly inhabits the warmer seas. Portuguese man-of-war jelly fish has a purple or bluish gas-filled bubble, which acts as a sail and helps in keeping it afloat on the water.
  • Sea Nettle: This type of jellyfish can be found both in warm, as well as cool sea waters. Sea nettles are abundantly found in Chesapeake Bay as they reside along the northeast coast of the United States.
  • Lion’s Mane Jellyfish: This type of jellyfish is the largest jellyfish found in the entire world. The diameter of their body is greater than 3 feet. They commonly inhabit the cooler, northern regions of the Atlantic and Pacific oceans.

5 Factors Which Increase the Risk of Getting Stung by Jellyfish

  1. Diving or swimming without wearing any protective clothing in regions, which are abundant with jellyfish.
  2. Swimming during the time of a jellyfish bloom, i.e. when jellyfish appears in large numbers.
  3. Swimming on a downwind shore.
  4. Sunbathing or playing on a beach where jellyfish has been washed up.
  5. Swimming in a place which has plentiful jellyfish.

Common Symptoms of Jellyfish Sting

  • Immediate pain, which has stinging, burning and prickling characteristics.
  • Appearance of red, purplish or brown tracks on the skin after being stung by jellyfish. This is displayed as a print of the contact by the tentacles with the skin. They can also be seen as raised welts or rashes.
  • Itching is present in most cases after being stung by jellyfish.
  • Other common symptom of jellyfish sting is swelling.
  • Patients with jellyfish sting also experience numbness and tingling.
  • Throbbing pain is felt, which radiates up the arm or the leg.

Severe systemic reaction to the jellyfish sting can appear immediately or after many hours after the sting. Seek immediate medical attention if the stings are over a large area of skin and if the patient experiences severe pain symptoms or has a serious allergic reaction to the sting.

Signs and Symptoms of Severe Jellyfish Stings are:

4 Factors Which Decide the Severity of Reaction to a Jellyfish Sting

  1. The size and type of the jellyfish.
  2. Patient’s age, overall health and size. Severe reactions following jellyfish sting are more likely to occur in children and those individuals who are in poor health.
  3. The duration of the time in which the skin was exposed to the stingers.
  4. The extent of the skin affected by jellyfish sting.

First Aid for Jelly Fish Sting

  • First thing to do after a jellyfish sting is to get the patient out of the water and tell him/her to remain as calm as possible.
  • Rinse the stung area with sea water.
  • Remove the stingers of jellyfish using tweezers or sticks. If these are not available, the gently scrape off the stingers using the edge of a credit card or ID card.
  • You can also use your gloved hands or towel to pull off the tentacles. Never touch the tentacles with bare hands.
  • Avoid rubbing the area or using fresh water or using ice/heat application before removing the stingers, as any change in the environment of the stingers will cause the nematocysts present in them to activate and fire more venom.
  • Avoid getting sand on the stung region.
  • Rinse the region affected by jellyfish sting with vinegar.
  • Apply a paste of baking soda paste or shaving cream/foam. This will help in preventing the spreading of the jellyfish toxins.
  • Ice/heat packs can be applied now, after removing all the stingers and tentacles of jellyfish. This will help in easing the pain.
  • Pain relievers can be taken and topical anesthetics and steroids helps with pain, swelling and itching arising from jellyfish stings.
  • Discard all the items which have come in contact with the jellyfish.

Treatment for Jellyfish Sting

Treatment for Jellyfish Sting

Majority of the jellyfish stings can be relieved by the simple treatment of:

  • Rinsing the stung area by Jellyfish with salt water.
  • Next soak the stung area by Jellyfish in vinegar for around 20-25 minutes. This will help in preventing the nematocysts from releasing the poison.
  • Alternatively you can also soak the affected region in 70% isopropyl alcohol or apply Safe Sea Jellyfish After Sting pain relief gel.
  • Never use fresh water after jellyfish sting, as the nematocysts continue to release their poison in fresh water.
  • For the same reason mentioned above, do not rub the stung area by Jellyfish and avoid any application of cold or hot water.
  • Using a pair or tweezers, the tentacles are removed.
  • Next, apply a paste of baking soda or shaving cream to the stung region.
  • Use a razor to shave the area so as to remove any adherent nematocysts.
  • Vinegar or alcohol is again reapplied. .
  • Application of shaving cream or baking soda paste helps in preventing the deactivated nematocysts from releasing their toxins during removal with the razor.
  • In case of jellyfish stings to the eyes, the eyes should be rinsed with a commercial saline solution, such as Artificial Tears. Soak and rinse a towel in vinegar and dab the skin around the eyes.
  • Avoid direct contact of the vinegar with the eyes.
  • For jellyfish stings to the mouth, mix ¼ cup of vinegar with ¾ cup of water. Use this solution to gargle and then spit it out. Do not swallow this solution.
  • Pain relievers, such as acetaminophen (Tylenol) or ibuprofen (Motrin) or Aleve can be taken every 6 to 8 hours for pain.
  • Medicines, such as diphenhydramine (Benadryl) help in relieving the itching.
  • Lidocaine or calamine lotion helps in alleviating itching and discomfort.
  • Topical or oral steroids help with the swelling as well as itching resulting from jellyfish sting.
  • Antibiotics can be prescribed if the patient has cellulitis after jellyfish sting.
  • Tetanus shot needs to be given if the patient’s last shot was more than 10 years back.

Emergency Treatment for Severe Reaction to Jellyfish Sting

  • Cardiopulmonary resuscitation (CPR) needs to be given if the patient is in shock after jellyfish sting.
  • In case of anaphylactic shock, epinephrine injection is given.
  • Patient will be put on life support for stabilizing the heart rate, breathing and blood pressure.
  • If the sting is from box jellyfish, then antivenin medication needs to be given.
  • Pain relievers for pain are given.
  • Oral antihistamines or corticosteroids are given for rashes, swelling and itching arising from after jellyfish sting.

Treatment Myths for Jellyfish Sting

These remedies are more or less myths and haven’t been proven to help in treatment of jellyfish sting:

  • Use or application of human urine after jellyfish sting.
  • Use of meat tenderizer.
  • Using solvents, such as ethanol, formalin and gasoline.
  • Application of pressure bandages.

How To Prevent Jellyfish Sting?

  • Always wear protective clothing, such as gloves, dive skins, wet suits etc. when swimming in the seawater.
  • Avoid swimming in areas which are jellyfish-infested.
  • Avoid picking up or touching dead jellyfish, as they still have active nematocysts, which can release toxins even after drying up.
  • If you are going to a region where jellyfish is common, try to find out what type of jellyfish is common in that area.
  • Always carry a first aid kit with you when going outdoors for swimming. Make sure that it contains an oral antihistamine.
  • Taking a course in basic first aid is beneficial before swimming at the beach or snorkeling or scuba diving.
  • When doing the above mentioned activities in the evening or at night, look carefully for jellyfish floating on the water’s surface.
  • Be prepared for a jellyfish sting and always carry Safe Sea Jellyfish After Sting® pain relief gel with you when swimming in the sea water.
  • If you already have a known allergy to insect sting, then always carry an allergy kit containing EpiPen.
  • Avoid touching marine life when you are swimming, scuba diving or snorkeling.

Also Read:

Pramod Kerkar, M.D., FFARCSI, DA
Pramod Kerkar, M.D., FFARCSI, DA
Written, Edited or Reviewed By: Pramod Kerkar, M.D., FFARCSI, DA Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:August 29, 2022

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