How to Deal with Sea Urchin Spines
If you don’t have a few purple urchin tattoos, you likely haven’t been diving hard enough. The purpose of this article is to prepare you to remove urchin spines from yourself or others. Key takeaway: carry a safety pin.
Background: The three categories of sea urchins include, long-spined urchins (diadema spp.), short-spined urchins (purple urchin Stronglyocentrotus), and urchins with pedicellaria (Deadly Flower Urchin Toxopneustes). Depending on the species, their defense mechanism is envenomation with or without a deep penetrating injury.
Figure 1: Diadema (left), Stronglyocentrotus (right)
Most Common Situation: Your significant other steps on an urchin at the beach. She is in pain with purple spines sticking out of her heel and toes. Immediate relief can come from immersing the envenomation site in hot water (109-114º F). Many of these toxins are inactivated heat. Immersion in cold water can numb the site but is less effective. To remove the spines, use a clean bobby pin and pick at the skin around the spine. Then pick down and flick the spine itself repeatedly without breaking it. You will see the spine work its way out of the skin. The goal is to use a sharp tool as narrow as the spine itself. I have personally found that repurposing sterile suture needles held with a hemostat is the best method. Tweezers do not work well as they are bulky and end up pushing the spine deeper into the skin.
If you cannot remove all the spines, it is not a big deal. I personally have had urchin spines in my fingers and knuckles for over 4 years. The urchin spine is calcium carbonate and is eventually encapsulated by fibrous tissue, most often remaining asymptomatic. If you want to try to dissolve an embedded spine, try soaking the region in vinegar early-on.
Locals in Hawaii, Mexico, and Indonesia suggest breaking up hard to reach spines into fine bits by hammering on it with a flat stick, beer bottle, or spoon. The thought process is that, when crushed finely, body absorbs and degrades the spines more rapidly.
Figure 2: Using a suture needle (left) and bobby pin (right) to remove Moroccan urchin spines after a surf session.
Rare Cases: In unfortunate cases, an embedded urchin spine can become infected, invade a joint, or cause chronic pain. If a spine was to become infected you would observe redness, swelling, and pus. If an urchin spine were to invade a joint you would observe redness, swelling, and immobility. The most common joints to be affected are the toes, knees and fingers. Chronic pain can result if a spine is in a weight bearing location.
Figure 3: Septic joint after foreign body went into the metatarsal-tarsal joint.
Interesting Case: The Flower Sea Urchin (Toxopneustes pileolu) is found along the west coast of the Pacific, from Indonesia to Japan. While beautifully designed with diverse appendages, they can deliver a powerful sting. This sting is known to cause intense radiating pain, a sensation of pins and needles, a drop in blood pressure, respiratory distress, and even muscular paralysis which may last up to 6 hours. Reportedly, a female pearl diver became unconscious after accidental contact with the flower sea urchin and subsequently drowned.
