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 won’t attack you, but because they live in shallow water and like to hide near rocks, you could step on or touch one accidentally.

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.

These features make sea urchins difficult for people to observe up close, especially in the sea on Gili Trawangan Island. Sea urchins are almost invisible due to the current sea level which sometimes rises and falls during the rainy season, so swimmers and divers must always be careful when stepping on shallow waters containing rocks, coral reefs, and hidden crevices.

What are the symptoms of a sea urchin sting :

If you get stung, your symptoms could vary depending on which of the 950 species of sea urchin has stung you. The most common symptoms for a single, shallow-water sea urchin puncture include :

1. Swelling in and around the area where you were stung.
2. Redness around the spine’s entrance point.
3. Sensitivity or pain,Infection if the sting is not treated.
4. Blue coloring where the spine pierced your skin, Muscle Aches.

If a sea urchin stings you more than once when you encounter it, your symptoms will be more serious and may likely include :

1. Extreme Tiredness.
2. Loos Of Strength.
3. Signs Of Shock.
4. Loss Of Feeling or the ability to move.
5. Trouble breathing And it can lead to death.

When to seek a doctor:

An allergic reaction to a sea urchin sting can occasionally be life threatening.

People who have a known allergy to sea urchins or other echinoderms, including starfish, should immediately go to the emergency room if they are stung.

People should seek emergency care for the following symptoms:

• Difficulty breathing
• Loss of consciousness, dizziness, or mood or behavior changes
• A sudden rash on a different area of the body from the sting
• Extensive swelling near the sting.

If someone is stung or suspects they have been stung by a venomous sea urchin, it is a medical emergency. They should go to the emergency room.

Some of the signs that the sea urchin sting may have been venomous include:

• dizziness
• changes in heart rate
• loss of consciousness
• nausea or vomiting
• difficulty breathing

When a sea urchin spine breaks off under the skin, it can migrate elsewhere in the body. If this happens, it may require surgical removal. If it is possible to feel a spine under the skin, if a spine is visible underneath the skin, or the spine has broken off, a person should contact a doctor.

When a spine is trapped under the skin or even after a spine is successfully removed, it is possible to develop an infection from a sea urchin sting.

Signs of an infection include red streaks coming out of the wound, an increase in pain, heat at the site of the wound, intense swelling, or a fever. A doctor should be contacted to treat signs of infection from a sea urchin sting.

Treatment of sea urchin stings :

A. First Aid.

• Soak the affected area in hot water (40–45°C) for 30–90 minutes. This will help inactivate the toxin and relieve pain.
• Avoid pressing or breaking the skin, as this will cause the spines to penetrate deeper.
• Avoid using blunt instruments or prying without medical guidance, as the spine fragments can break deeper.

B. Thorn Removal.

• Large, visible spines can be removed with sterile tweezers.
• Small, fragile spines are often left in place as they will dissolve/degrade within a few weeks, but monitoring is still necessary.
• Thorns in joints or tissues require medical intervention (sometimes minor surgery).

C. Medical Therapy.

Important Notes for Clinical Practice :

• Antibiotics are not necessary if the wound is shallow and there are no signs of infection.
• Small sea urchin spines that remain in the skin are often left alone and will dissolve on their own, but follow-up is necessary.
• For severe pain from sea urchin stings, a combination of Paracetamol and Ibu profen can be treated. However, these can be given alternately.
• Note the contraindications for NSAIDs in cases of stomach or kidney disease.

Follow-up Care.

• Apply a warm compress 2–3 times daily to the sea urchin sting.
• Apply a topical antibiotic ointment (mupirocin or fusidic acid) to the sea urchin sting.
• Avoid water activities until the wound has healed.
• Follow up if pain increases, swelling worsens, or signs of infection appear.

Complications of sea urchin stings.

• Bacterial infection
• Granulomatous synovitis occurs if the spines enter the joint
• Permanent skin pigmentation, tissue damage (necrosis), and abscess.
• Retained foreign body – a chronically embedded thorn can cause persistent pain
• Arthritis or tenosynovitis.

Prognosis.

Most sea urchin sting cases will heal completely within a few days to weeks. The prognosis for sea urchin sting cases will worsen if:

• A large number of sea urchin spines are retained.
• Injury occurs in the hands or sensitive areas of the feet.
• Infection or toxic reaction occurs on the skin when attacked by a sea urchin.
• Treatment is delayed.

Sea urchin sting prevention.

• If you’re in shallow or rocky areas of the ocean, keep an eye out for sea urchins.
• Watch where you step and where you put your hands to avoid surprise contact with them.
• Don’t go into the ocean at night if you know there are sea urchins in the area.
• Wearing water shoes or flippers might protect you from stepping on a sea urchin’s spines.
• A sharp spine or a high-pressure touch will still probably end up in a sting, even if you are wearing something on your feet.
• For the health of sea urchins, you shouldn’t touch them. If you have to touch one to move it out of your way, for example, handle it carefully and avoid putting too much pressure on the spines.
• If you’re unsure how serious your urchin sting is, contact your healthcare provider for a diagnosis and more information on how to treat your injury.
• People with a history of anaphylactic reactions to sea urchin stings should consider staying out of the water.
• Talking to a doctor about a reaction is advisable since it could be to a specific type of sea urchin only.

See Also: snake bite treatment

FIRST AID FOR SEA URCHIN.

• First aid for sea urchin stings requires prompt removal of the spiky spines.
• Removing sea urchin spines with tweezers can cause them to break and splinter at the skin’s surface.
• The spines might appear to be gone but can remain in the deeper layers of skin. Instead, it is advisable for a person to soak the affected area in vinegar. Vinegar can help dissolve the spines.
• The spines are gone when they are no longer protruding from the skin, and there are no black or gray dots remaining at the surface of the skin.
• If the first vinegar soak does not remove the spines, a person should continue applying vinegar compresses several times a day until the spines are gone.
• Warm compresses can help with pain and swelling. Nonsteroidal anti-inflammatory drugs, such as ibuprofen, can also relieve pain.
• In the days following the injury, a person should keep the wound clean and apply a triple antibiotic ointment. If the wound is red or itchy, topical hydrocortisone cream may help.

Conclusion :

Sea urchins are sphere-shaped or flat creatures that live in the ocean and are completely covered in protective spines. On the tips of these spines are tiny claw-like pincers called pedicellariae.‌ Sea urchins won’t attack you, but because they live in shallow water and like to hide near rocks, you could step on or touch one accidentally. ‌

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.(*)

References 

Halstead BW. Poisonous and Venomous Marine Animals of the World. U.S. Government Printing Office; 1988.

Auerbach PS. Auerbach’s Wilderness Medicine. 7th ed. Elsevier; 2016.

Fenner PJ. Marine envenomation: An update. Aust Fam Physician. 2017.

Haddad V et al. Injuries caused by sea urchins. Rev Med Trop. 2018.

Thomas P, Scott T. Guide to Treatment of Marine Envenomation. Clin Dermatol. 2002.

Wong et al. Sea Urchin Injuries: Review and Case Studies. Wilderness Environ Med. 2017.

Centers for Disease Control and Prevention (CDC). Marine Injury Guidelines. 2021.

Writer: dr. Jhon Trafolta Silitonga, AMF - General Practitioner & Chief Medical Officer Nusa Medica Clinic Gili Trawangan