Poisoning, envenomation, and trauma from marine creatures

In the course of their clinical work or during leisure activity, family physicians occasionally may encounter patients with injuries from marine creatures. Poisoning, envenomation, and direct trauma are all possible in the marine environment. Ciguatera poisoning can result from ingestion of predatory fish that have accumulated biotoxins. Symptoms can be gastrointestinal or neurologic, or mixed. Management is mostly symptomatic. Scombroid poisoning results from ingestion of fish in which histamine-like substances have developed because of improper refrigeration. Gastrointestinal and systemic symptoms occur. Treatment is based on antihistamines. Envenomations from jellyfish in U.S. waters and the Caribbean are painful but rarely deadly. Household vinegar deactivates the nematocysts, and manual removal of tentacles is important. Treatment is symptomatic. Heat immersion may help with the pain. Stingrays cause localized damage and a typically severe envenomation. The venom is deactivated by heat. The stingray spine, including the venom gland, typically is difficult to remove from the victim, and radiographs may be necessary to localize the spine or fragment. Surgical débridement occasionally is needed. Direct trauma can result from contact with marine creatures. Hemorrhage and tissue damage occasionally are severe. Infections with organisms unique to the marine environment are possible; antibiotic choices are based on location and type of injury. Shark attacks, although rare, require immediate attention.