Recognizing and Treating Sea Urchin Stings

Medically reviewed by Justin Choi, MD on August 29, 2017Written by Ana Gotter on August 29, 2017

What are sea urchins?

Sea urchins are small, spike-covered sea creatures that live in oceans throughout the world. They can be found in both warm and cold water, though they typically live in relatively shallow water like rock pools, coral reefs, or rocks exposed by the waves. Sea urchins aren’t aggressive, but their likelihood of being in shallow waters where people may be can result in our contact with them. This can result in an inadvertent sting.

While they’re beautiful to behold, sea urchins are extremely painful to make physical contact with. Most people are stung when they accidentally step on or touch a sea urchin, which can be easy to do in murky waters since they like to hide in crevices during the day. In some cases, people (particularly young children) may pick them up not realizing that they may sting.

What are the symptoms of a sea urchin sting?

Sea urchin stings are immediately painful. They often leave puncture wounds on the skin, which can easily become infected if not treated immediately. The stung area may become red and swollen. If the skin is punctured (which is common), the puncture site is often a blue-black bruised color.

Multiple deep puncture wounds can be a very serious injury, especially if accompanied with symptoms such as:

  • weakness
  • muscle aches
  • shock
  • paralysis
  • intense fatigue

These symptoms may lead to respiratory failure, and even death.

What causes a sea urchin sting?

A sea urchin has two defense systems. One is always engaged because it’s the natural, external body. This is made up of long, venomous spikes that are sharp enough to puncture skin. These spikes can also easily break off inside your body after the sea urchin stings you.

The second defense system is more active. It’s called the pedicellariae, which are essentially jaws that can release venom.

The immediate puncture wounds from the spikes will cause severe pain, especially because the spikes can potentially puncture fairly deep into the body.

Home treatments for a sea urchin sting

If you’re stung by a sea urchin, immediately remove any part of the sea urchin that’s embedded within your body. Use tweezers to remove the large spines. You can use a razor to gently scrape out the pedicellariae.

Once you do this, wash the affected area with soap and water.

To manage initial pain after the sting, you can take over-the-counter treatments like ibuprofen (Advil, Motrin) or acetaminophen (Tylenol). You can use topical antibiotic creams like Neosporin on the affected area at least three times a day. If the area is itching, you can use topical hydrocortisone cream.

Stop using the hydrocortisone immediately and call your doctor if there are any signs of infection, such as:

  • swelling
  • warmth, redness
  • fever
  • increased pain

Q:

Is it safe to have someone urinate on the area that was stung by a sea urchin?

A:

No, this is not recommended and has not been proven to be helpful.

Justin Choi, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

When to see a doctor

For deep puncture wounds, you should see a doctor.

If you’re experiencing pain for longer than four days after being stung, you should make an appointment to see your doctor. If you experience signs of infection at any point, seek immediate medical attention. You should seek immediate emergency attention if you’re experiencing symptoms such as:

  • muscle weakness
  • paralysis
  • muscle aches
  • extreme fatigue

When you see your doctor, they’ll ask about the sting, when it happened, and your symptoms. They’ll examine the area that was stung. If your doctor thinks a spine of the sea urchin may be left inside the body, they may use an X-ray to find its location and remove it. Your doctor may recommend that you get a tetanus shot.

If you have an infection, your doctor will likely prescribe antibiotics. Take the medication for the full course your doctor orders, even if your symptoms subside within just a few days. If the infection is severe enough, your doctor may admit you to the hospital for intravenous (IV) antibiotics.

If spines are embedded within the body or near a joint, they may require surgical removal.

Can sea urchin stings cause other conditions to develop?

If left untreated, sea urchin stings can cause a number of serious complications. The most common is infection from the puncture wounds, which can become serious very quickly.

Any spines broken off within the body may also migrate deeper if not removed, causing tissue, bone, or nerve injury. This could cause tissue death, joint stiffness, or arthritis. If you experience necrosis, or tissue death, go to the hospital immediately.

Shortness of breath or respiratory failure can happen in rare cases. This requires immediate emergency treatment, including oxygen supplementation and possible ventilation.

What is the outlook for a sea urchin sting?

Sea urchins are beautiful creatures, but like most animals in nature, they are best observed from afar. The stings can be severely painful and can cause a number of serious complications if not treated promptly.

With treatment, the pain and symptoms should subside within five days. If the pain hasn’t subsided, or if you see signs of infection or other complications, make an appointment to see a doctor as soon as possible.

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