Histamine Update

[winer]

So this means that there are histamines in BOTH the human body, and in the wine (absorbed from the skin of the grape). When you drink a red wine containing histames, do they "add to" the histamines already in the human body, or do they interact with those already there?

Another question: If it is the histamines that are the cause of headaches for some people, (like me) is there any way I could tell ahead of time what level of histamines there are in a given red wine? (I'm getting tired of the "trial and error" method.)