One thing that antibiotics and sugar have in common are that they both play havoc on the healthy bacterial in the gut. At least that is my understanding. The gut is quite important for the immune system, and many believe that it is quite important in general for health. Most doctors do not have this understanding. There are a large number of nerves supplying the gut, leading some to call it the 2nd brain. Why the sugar causes a flair-up, I don't know, but something to think about. Sounds like you should avoid sugar, which would be great for all of us, but I am certainly not willing to do so at this point, so I understand. Good luck.
Ron