Aquatic Antagonists: Lionfish (Pterois volitans)

Management

Individuals with lionfish stings should immerse the affected area in hot but not scalding water. Those with more serious injuries should seek medical attention. Home remedies that are generally contraindicated include application of topical papain or meat tenderizer.¹⁰ Data on ice packs are mixed, but because the toxin is heat labile, the most effective initial step in treatment is immersion of the affected area in water (temperature, 40°C to 45°C) for 30 to 90 minutes.⁶ The hot water inactivates the heat-labile toxin, leading to near-complete symptomatic relief in 80% of cases and moderate relief in an additional 14%. Immersion time more than 90 minutes considerably increases the risk for burns. Children should always be monitored to prevent burns. If a patient has received a nerve block for analgesia, the wound should not be immersed in hot water to avoid burns to the skin. The wound should be meticulously cleaned with saline irrigation, and radiography or ultrasonography should be performed as deemed necessary to look for any retained foreign bodies.⁸ Patients may require parenteral or oral analgesia as well as careful follow-up to ensure proper healing.⁹ Systemic symptoms require supportive care. Venomous fish wounds typically are small and superficial. Empiric antibiotic therapy is not advised for superficial wounds but may be required for clinically infected wounds.⁸ Tetanus prophylaxis should be given as appropriate to all affected patients. It has been noted that blister fluid contains high concentrations of lionfish venom, and when present, it increases the likelihood of converting the injury from a grade II to grade III wound with tissue necrosis; therefore, blisters should be drained or excised to decrease the chances of subsequent tissue necrosis.^11,12 If secondary infection such as cellulitis develops, antibiotics should be chosen to cover likely pathogens including common skin flora such as staphylococci and marine organisms such as Vibrio species. Wounds showing signs of infection should be cultured, with antibiotics adjusted according to sensitivities.⁵ Deeper wounds should be left open (unsutured) with a proper dressing to heal. Any wounds that involve vascular or joint structures require specialty management. Wounds involving joints may on occasion require surgical exploration and debridement.

Public Health Concerns

In an attempt to slow the growth of their population, human consumption of the fish has been encouraged. The lionfish toxin is inactivated by cooking, and the fish is considered a delicacy; however, a study in the Virgin Islands found that in areas with endemic ciguatera poisoning, 12% of lionfish carried amounts of the toxin above the level considered safe for consumption. This toxin is not inactivated by cooking or freezing and can lead to ciguatera fish poisoning for which there is no antidote and can be associated with prolonged neurotoxicity.¹³

Conclusion

As lionfish numbers continue to increase, physicians across multiple specialties and regions may see an increase in envenomation injuries. It is important that physicians are aware of how to recognize and treat lionfish stings, as prompt and comprehensive treatment provides benefit to the patient.