What type of poisoning is indicated by elevated plasma histamine levels after eating tuna?

Elevated plasma histamine levels after consuming tuna is indicative of scombroid poisoning. This condition occurs when fish, particularly those from the scombroid family like tuna, mackerel, and bonito, are improperly stored. When these fish are not kept at the right temperatures, bacteria can convert the amino acid histidine in the fish into histamine, leading to toxicity when ingested.

Patients suffering from scombroid poisoning typically experience symptoms such as flushing, rash, headaches, diarrhea, and gastrointestinal upset shortly after consumption. The elevation of histamine is a direct result of this biological process and is a key factor in diagnosing the condition.

In contrast, other types of poisoning listed do not typically produce elevated histamine levels as their primary symptom. Botulism results from toxins produced by Clostridium botulinum and is characterized primarily by neurological symptoms rather than histamine-related reactions. Mercury poisoning is associated with neurological and gastrointestinal symptoms but does not involve histamine. Ciguatera poisoning, linked to consumption of reef fish, causes symptoms from different neurotoxins and is not connected to histamine elevation. Thus, the specific rise in plasma histamine levels following the consumption of tuna is a hallmark of scombroid poisoning, solidifying the reasoning behind