Jellyfish stings leave a distinctive print of tentacles leaving narrow trail marks.
Jellyfish have tentacles with thousands of stinging cells called nematocysts.
They fire toxins when you bump or brush against them.
Illustration by Julie Bang for Verywell Health
These stings cause skin irritation, pain, blisters, and skinnecrosisor cell death.
The severe pain and burning from a jellyfish sting lasts about an hour or two.
As the pain subsides, it typically begins to itch.
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The itching can last for a week.
This gallery shows what different stings can look like.
It also explains how they should (and shouldn’t) be treated.
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Jellyfish Sting on Knee
This photo contains content that some people may find graphic or disturbing.
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Jellyfish stings have a distinctive look.
The sting often leaves a “print” of the tentacle.
Pete & Brook
You may see red, brown, or purple track marks on the skin.
Along with the marks, you may feel:
Seek emergency care if you have signs ofanaphylaxis.
This condition is a medical emergency which can lead to death.
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Jellyfish stings can usually be diagnosed by how they look.
It will still show faint tentacle marks.
Depending on the species and the number of stings, your reaction may range from mild to severe.
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If there are many stings, venom can build up in your blood vessels.
That can cause patchy redness, swelling, and burning.
In one camp, there are those who insist that distilled white vinegar will “neutralize” the toxins.
Mat Honan
Then they follow with soaking for 20 to 40 minutes in hot but not scalding water.
Using acold compressafter the soak may help ease the pain and inflammation.
Jellyfish Sting on the Feet
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Most jellyfish stings don’t need medical care.
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They can often be treated at home.
They should always be seen by a doctor.
Reactions may come on quickly or several hours after the sting.
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If you’re stung near the eye, flush the eye with lots of water.
Go to the nearest emergency room or call 911 if you’re able to’t drive yourself.
Anophthalmologistor eye doctor will need to remove any stingers and assess the injury.
You may need oral antibiotics to prevent infection and reduce the risk of eye damage.
The areas of redness, swelling, and inflammation are also larger.
Pufferfish stings are more spread out.
The marks are irregular with a cluster of raised sores.
Anemone stings are similar but more tightly clustered.
They sometimes develop blister-like sores that ooze.
Learning the difference between these types of stings can help you get the right treatment.
Some stings, like those from a man o' war, can be severe.
While man o' war stings can cause extreme pain, they are rarely deadly.
Far more serious is the box jellyfish of Australia.
They have caused eight deaths since 2000 with two in 2016 alone.
They can cause pain, swelling, redness, and itching.
For some people, they can also cause an allergic reaction that can be life-threatening.
To tell a jellyfish sting from other sea creature stings, look for narrow trails of tentacle marks.
A wide trail or one with random clusters is likely to be the sting of a different creature.
You’ll need to remove any stingers left in the skin.
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