Here is my situation: few days ago I had soy vanilla-flavored milk that I do not normally take. Less than an hour after that I noticed I had some trouble with swallowing and approximately 10 minutes later I started feeling pressure in my throat. I didn't have trouble breathing but my airways felt somewhat constricted. The feeling of constricted throat lasted for a day and half. Next day I woke up with post-nasal drip. The thing is that, as I mentioned above, I do not normally have soy milk. I only had it on 2 other occasions. The week before I also had vanilla soy milk (different manufacturer) in the evening and woke up with the exact same feeling of tight throat, that, again lasted for few days. It was followed with post-nasal drip like this time. At this point you would normally suspect soy allergy, but there are few things that just don't fit in. I had chocolate- flavored soy milk maybe a month ago (in fact, that was my first time to try it) with no reaction whatsoever. I also thought that it might be vanilla that is causing the issues but I had other vanilla-flavored drinks and products all my life and never had anything similar to this. Another thing worth mentioning is that I had some cold-related problems during this period. Sore throat on few occasions during 2 week period. At the time I took soy milk I was symptom- free, however. At first I thought my symptoms were cold related and I went to see the doctor and voiced my concerns. She said it was sinus infection and put me on antibiotics and post-nasal drip did disappear (could be coincidence) but it came back today. I have been taking antibiotics for 4 days now (2 more days to go) and this morning post-nasal drip resurfaced after 4 days of absence and 2 days since last having soy milk. So, my question is are these even symptoms of food allergy? If they are, would they last for so long after the exposure? The first time everything lasted for at least 7 days (there was no overlap though; 3 days of tight throat and then 4 days of post-nasal drip). I've never had problems of this sort, yet I'm sure I must have had soy before in some form( since it is commonly found in number of processed foods). Also, the first time I didn't have any problems in first couple of hours, only the next morning did the symptoms appear (although I did consume it in the evening). Do you think this is infection of some sort and the fact that my symptoms are preceded by soy-milk consumption is only a coincidence? I know this is really long, but I would be extremely grateful if somebody would give me his/her opinion. Thanks in advance.