I went through 5 weeks of testing at an Allergist, and the only thing he could report I was allergic too was chocolate, which I already knew. Talk about nasal allergies.
Anyway, he also told me I seemed "sensitive" to anything with vinegar in it, so he told me to watch my use of condiments, like ketchup, mustard, mayonnaise and the like, which at the time made sense, because I was known to drown my French Fries in ketchup. I eventually learned to add some ketchup to the plate, and then just "dip" them in the ketchup.
The day I had the outbreak, my office mate was going to pick up lunch, and I asked her to get mine as well, which it turned out to be ham and cheese with mustard, and the guy at the deli must've drowned the sandwich with it, because my office mate wound up taking me to the hospital later that afternoon. They gave me a shot of something (don't recall what now), but it eventually wore off, so a friend gave me the name and telephone number of her Allergist, and off I went the next day to start testing. It also put off my vacation for a month. ~shakes head~