If it's any comfort, my experience may help ease your mind. Years ago I converted on a PPD test (i.e., I had a severe reaction to a skin test for tuberculosis). For this reason, I was very reluctant to undergo BCG treatment. I mean, what if my bladder reacted the way my arm did? My uro sent me to an infectious disease specialist, who found no active TB in my system, and she recommended that I take the BCG treatments at half dose, just to be on the safe side. I have since had 2 treatments with minimal side effects (fatigue & mild headache for a couple of days). 4 more to go, but I am no longer apprehensive.