Sea urchins have two types of poisonous organs. The spines, or barbs, produce puncture wounds and pedicellaria lie between the barbs and release a toxin when they attach to an object. When a sea urchin feels endangered, they point their barbs in the direction of the threat. One barb in the foot, though painful, is not generally serious unless an infection develops. However, multiple barbs in the foot can lead to serious health problems.
Sea urchins inhabit oceans all over the world in warm and cold waters. Circular-shaped and small -- between 1.2 and 4 inches in diameter -- sea urchins have a spiny shell covering their body. Packed, fitted plates of their skeletal shell protect them from injury. Camouflaged, movable spines, or barbs, outline the shell to protect them from predators. Sea urchin colour varies from red, light pink, purple, brown or black. Inhabiting rock pools, mud, exposed rocks, coral reefs and sea grass beds, these nocturnal creatures normally hide in holes and crevasses in the daytime and look for food at night.
Soak the affected foot in water that is as hot as can be tolerated for 30 to 90 minutes. Repeat this if the pain persists. Use clean tweezers to remove large barbs in the foot and do not use your fingers. Apply shaving cream to the affected area on the foot and scrape it off with a razor to remove the pedicellaria. After pulling out the barbs and removing the pedicellaria, scrub the affected area with soap and water and then rinse thoroughly with clean water. Take acetaminophen or ibuprofen to help reduce the pain.
Sea urchin barbs in the foot can cause numbness, pain, swelling and lead to an infection if not treated. Signs of an infection include redness, pus and heat at and around the wound. If an infection of the foot occurs, contact a physician, who may prescribe antibiotics or an antibacterial ointment. Numerous deep puncture wounds may lead to shock, weakness, fatigue, muscle aches, respiratory failure, paralysis and in extreme cases, death. Seek immediate medical attention if breathing problems or chest pain occurs. Spines that enter near or at a joint may require surgery for removal.
When visiting the ocean, watch carefully when walking to prevent stepping on sea urchins, especially around rocky areas or coral. If walking in an area covered with sea urchins, try to find an alternative route. Avoid picking up sea urchins because they see humans as a threat. By handling these creatures, the protective covering on their skin and scales that guard them against predators can sustain damage.