Treating a Sea Urchin Sting

Treating a Sea Urchin Sting

October 26, 2018Sea Urchins10290Views39Comments

“Take nothing but pictures, leave nothing but bubbles.”

While most divers know and respect this mantra, there are certain instances when unexpected or unavoidable immediate contact with marine animals can occur. Tide pools and intertidal zones are great places to observe marine wildlife, but they also present the risk of getting too close to something that can intentionally or inadvertently injure you—like the sea urchin.

Sea urchins are spike-covered spherical creatures that are usually just small enough to fit in the palm of your hand—they can measure around 1.2 to 3.9 inches in diameter. They also come in different colors, although the most common are black, brown, purple, red and green.

Are Sea Urchins Poisonous?

colorful red and purple sea urchins on coral reef

Sea urchins are related to “harmless” sea creatures like sand dollars, sea stars, and sea cucumbers. They are omnivorous creatures that only feed on very small plants and animals like seaweed, algae, plankton, and decaying organic matter. Their insides (gonads and roe) are actually considered a popular seafood delicacy.

Despite the fact that they aren’t considered dangerous, sea urchins do have a physical defense mechanism that can be harmful—their sharp spines, which are certainly hard to miss. These spikes, which cover nearly every inch of their bodies, serve as their first defense against predators. The spines themselves are not venomous, but they do have pedicellariae (small, claw-shaped jaws attached to the sea urchin’s shell) that bite and release painful venom to serve as their second defense system.

These features make sea urchins difficult for people to observe up close, so swimmers and divers should always be cautious when treading shallow waters where there are rocks, coral reefs, and hidden crevices.

How to Treat a Sea Urchin Injury

red sea urchin in hand

The main disadvantage of being impaled by a sea urchin, besides possible envenomation, is that the spines are very brittle and can be left embedded deep into your skin tissues. Some victims of sea urchin stings will have spines stuck beneath their skin long after the initial contact, either due to the difficulty of removal or indifference to their presence.

Sea urchin puncture wounds will often look bruised (blue-black in color). The area may also become swollen and reddish, plus it can get infected if the sting is not treated right away.

While a sea urchin sting is easily treated, it’s nothing to be cavalier about—do not ignore it. Multiple puncture wounds (especially deep ones) can be severe enough to cause intense fatigue, shock, paralysis, breathing problems, or even respiratory failure leading to death. Thus, it’s important to seek immediate medical attention if you’re unable to remove the spines yourself.

Here are some tips to remember when attempting to treat your own wounds:

Carefully remove the spines

It’s important that you immediately remove any spines that have gotten into your skin. If the spines are protruding enough that you can get a hold of them with tweezers or pliers, do so slowly and with care. If there are any pedicellariae, you can use a razor to gently scrape them out of your skin.

Some people are familiar with removing splinters with a needle and may find that method to be effective with sea urchin spines, but it is crucial that you sterilize the needle before you use it to dig into your flesh.

As previously mentioned, sea urchin spines are brittle and, like splinters, have the potential to break into pieces as you attempt to remove them. Take care not to crush the spine with your implement and use as steady a hand as possible.

Clean the affected area

Once you’re sure that you’ve removed all signs of the sea urchin from your body, it’s time to wash the area. Whether you use an antiseptic cleanser, hydrogen peroxide, or just good ol’ soap and water, it is very important that you clean the punctured area to avoid any risk of bacterial infection.

Use the hottest water you can possibly stand without scalding yourself and soak the affected area in it for about 20 minutes until your skin prunes. You can even add Epsom salt to boost the skin softening effect.

Soaking in hot water is advantageous for a few reasons: it helps manage the pain, keeps the wound clean, and will also enable easier removal of the spines because your skin will be more pliable. If you have been envenomed and are experiencing pain, a vinegar soak will help neutralize the toxins and relieve some of the discomfort.

Recovery and aftercare

For a couple of days after the removal of the spines, continue to soak the wound in hot water several times a day. Apply a topical antibiotic ointment like Neosporin on the affected area thrice a day after washing and drying the skin.

Topical hydrocortisone cream can also be used for any itching around the affected area.
You can also take over-the-counter pain medications like Advil (ibuprofen) and Tylenol (acetaminophen) if you are experiencing any pain.
Be sure to use fresh bandages to keep puncture wounds clean until they have healed.

Consider seeking medical help

If you have tried but failed to successfully remove the spines, see a medical professional as soon as possible. Remember that you should not attempt to do the removal yourself if you are dealing with deeply embedded or large spines, multiple or deep puncture wounds, or punctures near joints, as these may require surgical removal.

Also, call your doctor if you are experiencing increased pain; if the pain doesn’t go away after the fourth day; or if you see any signs of infection, like swelling, warmth, redness, and fever. Your doctor will either give you a full course of antibiotics that can be taken at home or have you admitted to the hospital to receive antibiotic treatment through an IV.

Being extra careful doesn’t always mean that you won’t get hurt or injured—especially when you’re in the ocean. It’s even possible to get stung by a spiky sea urchin even when you’re on the shore because some of them do end up on the sand, where people can accidentally step on them. What you need to remember is that it is important to have yourself treated immediately to avoid any serious complications like infections, spikes migrating deep inside your body, or other dangerous bodily reactions that can lead to more dangerous health risks.


  1. Stepped on a sea urchin when I was at gitmo getting out of the water during a dive while serving in the Coast Guard .I went to sick-bay they cleaned it put me on light duty for a wk and told me my body will absorb the spines ….

  2. Apply lots of vinegar after a good gentle cleaning and removing any spines. Leave the compress of soaking vinegar on for as long as you can even overnight. Take a good hot tub bath and soak as long as you can as many times as you can. This should go on until you don’t see any of the spines under the skin as the vinegar helps to dissolve them. They will go away in about a week with this process. Leaving them in will possibly promote arthritis and paralyzation of half of your body . This happened to two of my dive partners who didn’t use the vinegar to dissolve the spines. Both were hospitalized. This remedy has worked well for me many times in Hawaii where Ive lived and dove for over 30 years.

    1. Using hydrogen peroxide might be fine for the initial cleaning but I recommend alcohol. Hydrogen peroxide can inhibit new cell growth. I personally don’t use it in tropical environments. I agree with seeking medical attention if the spines are deep or very plentiful.

  3. I ran into one in my left chest on a dive on the YO257 off of Oahu, didn’t have any treatment, did take a time to get rid of the black spots on my chest, the spines were like glass, just broke off if tried to remove. Just let it assimilate into my system, no adverse affects

  4. Just remove what you can. Then, get a piece of wood, and start hitting yourself in the area affected. Spines will break in your skin, and disappear after a while. It worked for me a long time ago. =)

  5. Fear friends in turkey they are not poisinous. So if it had broken inside and no part seen outside , we put alittle olive oil and the skin gently spits it out by itself in few days.

  6. This happened to me back in 2003′. My situation was far worst . I had over 9 my entire arm was purple. I had no idea what to do nor did the dive crew and captain.
    Learning experience!!!

  7. Large part of my lower arm, pulled out what I could and then put it in hot / warm water for an hour and rubbed lemon over it, Sorted. Just had a few black marks for a couple of days. The spines are made of Calcium Carbonate so dissolve in acid and hot water.

  8. Dove into shallow water and hand came down right on top of urchin. My hand looked like the one in pic. Spines all broke at surface leaving 20 or so buried under skin. Surprising, there was little initial pain and no lingering pain. All pieces eventually dissolved or worked themselves out like a splinter does. Overall it was no big deal.

  9. I was pushed into one while snorkeling off the coast of St John, USVI in ’08. I had 2 dozen spines in my ankle. I soaked it in a 50/50 mix of water and acidic acid. I had trouble swimming back to shore. I was able to start my open water certification class in 24 hours.

  10. A diabetics hypodermic needle is best to perpindicularly pry them out from under the skin. After the spine festers up a bit you will need to enlarge the original hole to allow the spine a path to come up. Use tweezers when you can get it out far enough to get a hold of. Be wary of spines lodged in joints and tendons as they never will come out and you must have surgery. Also, they can migrate through through soft tissue and come out years later . Having been a 25 year Sea Urchin harvester in California,I have excised many in my hands feet and knees and also have had to go under the knife for one lodged in a knuckle. I have even sliced into the soft tissue of myself to get at some spines. Its not really that big of a deal just use good basic sterile techniques with common rubbing alcohol and tend to any resultant wounds appropriately.

  11. There’s an Urchin sting first aid kit out and available made by Ocean Care Solutions..has everything you need in it..tweezers..saline solution..bandages..ointments..the works…check it out…good to have on hand…

  12. I sat on one a few weeks ago in mexico and I couldn’t do any of this. Maybe that’s why I still have the marks:P

  13. I was rock diving from a boat in Port Orford Oregon, and there were so many of them it was hard to avoid them, I ended up getting spined on the backside of my hand and it was painful.

  14. My cousin used to live in the Netherlands Antilles and he once stepped one an urchin. My aunt took him to the doctor who told them the spines were too deep to extract and then the doctor rolled the area back forth to break them up as much as possible (sure hope he used novacaine first)!

  15. We have seen a man treated in bali..the locals used a spoon and crushed the spines and then applyed a local leaf…our friend had no more trpoble with his foot

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.