Control Freak - how did I get that hangover?

Recently I had an unpleasant allergic reaction to beer. Not in the "I had too much of it" way but more in the "it caused severe congestion, sinus blocking and even swollen eye-lids (not the result of a fight outside the pub)" way. It's not necessarily the alcohol and can be anything from histamines to wheat to some random ingredient in a beer that my body dislikes.



Being a scientist, I'd like to work out what it is that causes this reaction as it's happened several times in the past. I also don't want to simply stop drinking beer because a) I like it and b) the majority of beers don't have this affect on me.

Good old wiki has a useful guide on how to try and identify the problem but for the purpose of my "control freak" entry I have a slightly different scenario. Basically on the night in question, I had 4 beers - 2 pints of beer "A", 1 pint of beer "B" and 1 bottle of beer "c".
Beer "A" I have drunk before (and had four of one occasion) and I've never had a problem with it so I think I can rule that out.
Beer "B" - I've never had before so could be a culprit.
Beer "C" - I've never had before so could also be a culprit.

I reckon I can exclude beer "A" but for the sake of the experiment I should try and drink all three beers separately to see what happens. I should also try and mimic the environment of that drinking session which was in the evening before a meal - maybe the empty stomach was the culprit?. I should also take into account that the Chinese meal I had may have caused the allergy (I admit I was having a "lazy Friday"). Rather than have a Chinese every time I think I may just include that with the water control at some point. The trials should be as follows.

1) have  water  - have a high "n" number for that already.
2) have  beer "A"
3) have  beer "B"
4) have beer "C"

I'm reluctant to try 4 of each beer as it potentially means I'd be having 4 times the amount that caused the last unpleasant reaction so will start with one. If none of them show up I'll try more.

If one of them does cause the allergic reaction then I can check the ingredients of the culprits to see what may be the culprit. I could follow this up by trying another beer that has a lot of the suspect allergen - if that results in a reaction I know it's best to avoid beers containing that allergen in high quantities alone.

You could argue this isn't exactly an unpleasant experiment to carry out seeming though it involves drinking and eating Chinese take-aways but trust me it won't be the case if I have the same allergic reaction again.
If anyone has any other useful strategies for identifying said culprit, feel free to share. I know there's a few beer lovers out there!