What Causes Recurring Itchy Blistery Rashes?

I have a blistery rash...several spots....when the bumps get itcy, they will break with blistery fluid coming out. Then the spot looks like a center with a flowery raised circular area around it. Some of those areas later become itcy and the process repeats.....sometimes not. My Dr doesn t know....has put me on Bacitracin as she thinks I have a staph from scratching?? HELP