Case Reports
Don’t Get Hung Up on Fishhooks: A Guide to Fishhook Removal
In the sport of fishing, barbed fishhooks often are used for their effectiveness in maintaining the fish on the hook once it is caught.
Comment
Sea urchin spine injuries are commonly seen in coastal regions with frequent participation in recreational and occupational water activities. A wide variety of responses can be seen in sea urchin spine injuries. There generally are 2 types of cutaneous reaction patterns to sea urchin spines: a primary initial reaction and a secondary delayed/granulomatous reaction. When the spines initially penetrate the skin, the primary initial reaction consists of sharp localized pain that worsens with applied pressure. In addition to pain, bleeding, erythema, edema, and myalgia can occur.3 These symptoms typically subside a few hours after complete removal of the spines from the skin.6 If some spines remain in the skin, a secondary delayed/granulomatous reaction can occur, which can lead to the formation of granulomas that can manifest as nodules or papules and can be diffuse.
Many patients may think their painful encounter with a sea urchin was just an unfortunate event, but depending on the location of the injury, more serious extracutaneous reactions and chronic symptoms may occur. Some cases have described the development of arthritis and synovitis from the implantation of spines into joints.1,2,4-6 Other extracutaneous complications include neuropathy and paresthesia, local bone destruction, radiating pain, muscular weakness, and hypotension.3
The severity of the injury also can depend on the sea urchin species and the number of spines implanted. There are approximately 80 poisonous sea urchin species possessing toxins in venomous spines, resulting in edema and change in the leukocyte-endothelial interaction.9 Substances identified in the spines include proteins, steroids, serotonin, histamine, and glycosides.3,9 The number of spines implanted, particularly the number of venomous spines, can lead to more severe complications. Penetration of 15 or more venomous spines can commonly lead to extracutaneous symptoms.3 Another concern, irrespective of species type, is the potential for secondary infection associated with the spine penetration or implantation into the skin. Mycobacterium marinum infections have been reported in some sea urchin granulomas,10 as well as fungal infection, bacterial infection, and tetanus.3
The diagnosis of sea urchin spine injuries starts with a thorough history and physical examination. A positive history of sea urchin contact suggests the diagnosis, and radiographs can be useful to find the location of the spine(s), especially if there are no visible nodules on the skin. However, small fragments of spine may not be completely observed on plain radiographs. Any signs or symptoms of infection should prompt a culture for confirmation and guidance for management. Cutaneous biopsies can be helpful for both diagnosis confirmation and symptomatic relief. Reported cases have described granulomatous reactions in the vast majority of the histologic specimens, with necrosis an additional common finding.7,8 Sea urchin granulomas can be of varying types, the majority being foreign-body and sarcoid types.3,6,7
Treatment of sea urchin spine injuries primarily involves removal of the spines by a physician. Patients may soak the affected areas in warm water prior to the removal of the spines to aid in pain relief. Surgical removal with local anesthesia and cutaneous extraction is a common treatment method, and more extensive surgical removal of the spines is another option, especially in areas around the joints.2 The use of liquid nitrogen or skin punch biopsy also have been described as possible methods to remove the spines.11,12
Conclusion
Sea urchin spine injuries can result in a wide range of cutaneous and systemic complications. Prompt diagnosis and treatment to remove the sea urchin spines can lessen the associated pain and is important in the prevention of more serious complications.
