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- Epidemiology: the most common fish-associated nonbacterial food poisoning in the United States, with most cases occurring in Florida and Hawaii
- In all, 20,000–50,000 people are affected annually.
- Three-quarters of cases involve barracuda, snapper, jack, or grouper found in the Indian Ocean, the South Pacific, and the Caribbean Sea.
- Pathogenesis: Ciguatera toxin is created by microalgae, whose consumption by fish allows the toxin to accumulate in the food chain. Three major ciguatoxins—CTX-1, -2, and -3—are found in the flesh and viscera of ciguateric fish, are typically unaffected by external factors (e.g., heat, cold, freeze-drying, gastric acid), and do not generally affect the fish (e.g., odor, color, or taste).
- Clinical features: Virtually all pts are affected within 24 h; most experience symptoms within 2–6 h. The diagnosis is made on clinical grounds.
- Symptoms can be numerous (>150 reported) and include diarrhea, vomiting, abdominal pain, neurologic signs (e.g., paresthesias, weakness, fasciculations, ataxia), maculopapular or vesicular rash, and hemodynamic instability.
- A pathognomonic symptom—reversal of hot and cold tactile perception—develops within 3–5 days and can last for months.
- Therapy is supportive and based on symptoms.
- Cool showers, hydroxyzine (25 mg PO q6–8h), or amitriptyline (25 mg PO bid) may ameliorate pruritus and dysesthesias.
- For 6 months after disease onset, the pt should avoid ingestion of fish (fresh or preserved), shellfish, fish oils, fish or shellfish sauces, alcohol, nuts, and nut oils.