Scorpionfish are colorful venomous marine animals found primarily in tropical waters. Their exotic beautiful appearance has made them increasingly popular among marine aquarists in the United States. Many envenomations have resulted from mishandling. They are well camouflaged in the wild. Stings are usually caused by accidentally stepping on them. Scorpionfish are grouped into the genera Pterois (lionfish), Scorpaena (scorpionfish proper), and Synanceja (stonefish), in order of increasing severity of envenomation. All have multiple spines associated with venom glands. Envenomation results from skin puncture followed by venom release. Immediately following a sting, the victim experiences intense pain that lasts for hours if untreated. The envenomation site may become warm, erythematous, and edematous, and vesicles may arise. Lionfish stings are painful but relatively mild, while systemic effects are more common with stonefish stings and may produce a constellation of cardiovascular, pulmonary, neurologic, and gastrointestinal sequelae. Death has been reported from stonefish stings.
Lionfish (Pterois volitans). Envenomations occur by contact with the erectile spines on the dorsal, pelvic, and anal fins of the fish. (Photo contributor: Kevin J. Knoop, MD, MS.)
Scorpionfish. The scorpionfish is well-camouflaged, leading to accidental contact and envenomation in unsuspecting divers. (Photo contributor: Kevin J. Knoop, MD, MS.)
Management and Disposition
Hot water immersion (43°C-46°C [109°F-115°F]) for 30 to 90 minutes should be initiated as soon as possible. Rebound pain is common and can be treated with repeated hot water immersion. The wound should be inspected for pieces of spine and sheath. Thorough warm saline irrigation should be performed along with wound exploration. Severe pain is treated with local injection of lidocaine without epinephrine and with opiate analgesia. Antibiotic prophylaxis should be considered in high-risk wounds and tetanus prophylaxis given, if indicated.
Stonefish stings are the most dangerous. Severe systemic reactions may occur. Antivenin (Commonwealth Serum Labs, Australia) is available.
Scorpionfish venom is heat labile. Hot water immersion is effective in treating pain and inactivating venom.
Since 2002, Indo-Pacific lionfish have been reported in increasing numbers from New York to the Bahamas.
Stonefish. The highly venomous stonefish is well-camouflaged. Envenomation usually results when the victim steps on the fish. (Photo contributor: Ian D. Jones, MD.)