Canned Fish Allergy?

[nellafallen]

First let me start off by saying I love all types of seafood. However, I found out at a very young age that I was apparently allergic to tuna and salmon, feels like I am having a heart attack with severe chest pains and it becomes difficult to breath. What I didn't know was that it was actually only canned tuna and salmon that I am allergic to. I recently got the nerve to try fresh salmon and tuna and had no reaction what so ever. Thinking maybe I had grown out of my allergy toward it I tried tuna from a can and had the same chest pain shortness of breath reaction. Needless to say I wont be doing that again but at least I know I can eat fresh fish (and it tastes better anyhow). The strange thing is I can eat canned oysters and other canned goods with no reaction. Does the canning process alter fish? If so what exactly is causing the reaction and why doesn't it have the same effect on other canned goods? Anyone heard of this before?