Scombrotoxin poisoning: an important differential diagnosis for anaphylaxis.

We report a case of scombrotoxin poisoning, an acute illness that develops within minutes to hours of eating poorly processed oily fish, such as tuna or mackerel. It presents with symptoms that can mimic an anaphylactic reaction. It is presumed to arise due to ingestion of histamine that is formed by contaminating bacteria that have flourished during periods of suboptimal refrigeration, following capture. Knowledge of this underdiagnosed malady as a potential differential diagnosis for patients presenting with symptoms suggestive of histamine release is important. It is a notifiable condition. The alternative diagnosis of anaphylaxis may have significant lifestyle implications for the patient. This article reports on one such presentation and the way that the diagnosis was explored.