I know everyone on this site means well, but be very cautious about these diagnoses that it's a sensitivity and not an allergy. From what you described, you sound as if you were very close to anaphylaxis, which can kill you in a matter of minutes. Symptoms can include turning bright red, itching around the ankles and wrists, developing hives, swelling of the lips and other mucus membranes, shortness of breath, chest tightness, nausea and/or vomiting, and dizziness. I developed this kind of acute allergy to orange juice in the 1980s, after literally decades of drinking it every day for breakfast.
That's the nature of allergies -- they can come and go. But as my allergist says, if your reaction is THAT severe, you don't want to take chances by trying "just a little bit." Just because it didn't kill you this time, doesn't mean it won't the next. Not cheerful, but that's the reality.
I hope you will consult (or have consulted) a physician. He or she can do a challenge test, although some allergists don't like to do that, even under controlled conditions, because there's always a risk of a very severe reaction. Skin patch tests aren't as reliable. Often, the doctor will just take your history and make a sort of a presumptive diagnosis. He or she can give you a prescription for an Epi-Pen (adrenaline). Learn how to use it and carry one with you at all times. When your blood pressure drops, it is a necessity. (You haven't lived until you've "shot" yourself in an airplane restroom!)
<message edited by rumaki on Tue, 06/14/11 9:54 AM>