However, according to Dr. Tran Thi Hieu - Department of Nutrition, Thu Duc Regional General Hospital, this is not a fish allergy in the usual sense, but a form of Histamine poisoning, a form of food poisoning that can be prevented if understood correctly and the fish is properly preserved.
The meat of marine fish such as mackerel, tuna, herring, ngan hang... already contains Histidine, a natural amino acid, completely harmless when the fish are fresh.
However, when fish are not cooled early and left at a normal temperature for too long, bacteria will break down Histidine, converting it into Histamine, a dangerous toxin.
The concern is that Histamine is not destroyed by heat. Whether the fish has been fried, cooked or steamed thoroughly, this toxin still exists. Therefore, if many people eat a batch of fish contaminated with Histamine at the same time, they may have the same reaction at the same time, Dr. Hieu analyzed.
Common symptoms include redness, itching, headaches, dizziness, nausea, diarrhea, which can easily be mistaken for an allergy or anaphylaxis, even if it is not a real allergy.
How to choose and store fish to prevent poisoning
According to nutritionists, temperature control is a key factor in preventing Histamine from forming. The fish should be refrigerated immediately after catching or after purchasing, stored continuously at 0-4°C, not kept at room temperature for more than 2 hours and avoid defrosting and freezing many times.
When choosing fish, you should prioritize fresh fish with clear eyes, red bring, firm meat; avoid fish with a strange smell, viscous surface or soft, mushy meat. In addition, bring out the bring and internal organs early because this is where bacteria thrive, and do not leave the cleaned fish in the refrigerator for too long before processing.
Histamine poisoning usually occurs after 10-60 minutes of eating fish, with symptoms such as redness of the face, neck, ears, hives, burning, headaches, nausea. In severe cases, it can be difficult to breathe, low blood pressure, rapid heartbeat, dizziness or fainting, need to take the patient to a medical facility immediately for timely monitoring and treatment.
Dr. Tran Thi Hieu emphasized that marine fish is still a nutritious and safe food if properly preserved. Histamine poisoning occurs mainly when the fish is damaged but is difficult to recognize with the naked eye.
Families and collective kitchens need to choose a reputable source of supply, maintain a cold chain and carefully check food senses. When there are signs of suspected poisoning, do not be subjective but need to take the patient to the hospital early, the expert recommended.
