I'm pretty good at avoiding the hot foods, but the crunchy ones get me. Like Cap'n Crunch. And Snyder's pretzel nuggets! Especially the savory ones, because I have to suck the seasoning off first. Popcorn -- I always end up with at least one cut on my gums. And Nerds -- crunch *plus* citric acid.
I have the itchy mouth reaction to raw pineapple and all raw stone fruits -- peaches, plums, nectarines, cherries. All my favorites. Sometimes it's worth the itch.