[2][4] Symptoms may include flushed skin, sweating, headache, itchiness, blurred vision, abdominal cramps and diarrhea.

[2] Rarely, breathing problems, difficulty swallowing, redness of the mouth, or an irregular heartbeat may occur.

[2][5] Scombroid occurs from eating fish high in histamine due to inappropriate storage or processing.

[2][6] These fish naturally have high levels of histidine, which is converted to histamine when bacterial growth occurs during improper storage.

[9] Histamine is the main natural chemical responsible for true allergic reactions, so the symptoms produced are almost identical to a food allergy.

In September 2016, authorities in Singapore intercepted canned tuna imported from Thailand after finding high levels of histamine.

The Shenzhen Post reported that histamine poisoning from scombroid fish happens often in the autumn in Guangdong province in China.

In 2012, UK environmental health authorities in north east Lincolnshire intercepted and destroyed a shipment of tuna from Vietnam after four crew members were reported to have developed symptoms of histamine poisoning.

[15] Commercially canned tuna was determined to be the cause of the poisoning of 232 persons in the north-central United States in 1973.