I haven't been diagnosed yet (and I may turn out to have something entirely different) but I hadn't had ulcers either until this past week. I got one beneath my tongue which lasted for four days.. the same four days in which my joints flared up with pain and I was struggling to walk.
Mine was much like yours sounds, bright red and white in the middle and I'm so glad I only had one ~hugs you up~
Will watch this for the response of the others as I'm interested to hear their answers too!
Numpty:- (num-p-tee) dialect, chiefly Scot, ~n. 1. a bumbling fool: one who is intellectually challenged. 2. widely known in Scotland as an MSP (Member of Scottish Parliament).