The gastrointestinal form may appear hours or days after ingestion with nausea, vomiting, diarrhea and abdominal pain. Stop eating if oral sensations are perceived. Empty stomach if systemic symptoms are noted, using emetic or lavage. Give respiratory support and monitoring if needed. Fish left at room temperature undergo bacterial breakdown of tissue histidine to histamine and saurine.
Spoiled fish have a sharp, peppery taste.
Occur in the first hour, and a histamine-like intoxication is seen. There is headache, flushing, dizziness, palpitations and tachycardia. One may see hypotension, bronchospasm, urticaria and anaphylaxis. GI symptoms include nausea, vomiting, diarrhea, abdominal pain, thirst and dysphagia. Antihistamines appear to be helpful.