Sea urchins are covered with long, sharp, sometimes venom-coated spines. Touching or stepping on these spines typically causes a painful puncture wound. The spines commonly break off in the skin and cause chronic pain and inflammation if not removed. Joint and muscle pain and rashes may develop.
Sea urchin spines should be removed immediately. Because vinegar dissolves most sea urchin spines, several vinegar soaks or compresses may be all that is needed to remove spines that have not penetrated deeply. Surgical removal may be required for imbedded spines. (X-ray imaging is usually not necessary before surgery, but it may be required if the doctor suspects but is uncertain that there are imbedded spines.) Soaking the injured body part in hot water often relieves the pain.
(See also Introduction to Bites and Stings Introduction to Bites and Stings Many creatures, including humans, bite when frightened or provoked. Others include Alligators and crocodiles Iguanas Mites Ticks read more .)