I always have a CD flare after, or during a sinus infection...I also get the mouth sores at the same time. In fact the mouth sores seem to "announce" that one will follow the other. My doctor explained that during a sinus infection, post nasal drip down your throat and into your tummy,/bowel triggers an inflammation.....seeing as the with CD patients your GI system is super sensitive to "invaders" or overeacts automatically to something foreign. With me...I had chronic sinusitis for years and with it the above problems. An MRI revealed how seriously infected my sinuses were. I was on antibiotics for months and suffered a terrible flare. ...but once the sinuses cleared up ....my tummy followed suit.
I also have an eczema patch on one hand that never goes away....but gets much worse during a flare....and then my other palm develops a same problem. When the flare is over, the one hand gets better but never the other.
50 yr.old retired RN,Crohn's D for last35 yrs..severe esophagitis, migraines,strictures,urethral stricture,depression,probable MS.