Hello Teri ,unfortunately yes ,I'm one of those unlucky ones suffering with rashes and hives many days and suddenly. Mine are kind like pimple look but hurts when something rose then,hurts for real.
Mine are not on my rsd area ,well the one officially diagnose ,but according with some dr my rsd was spreading and feels like they are triggering my pain more.they are around my belly or back,trigger by sweet or heat,any warm weather changes send me stray to flare ,dr only recommended Benadryl and try not to stress,you right ! Like is easy to have pain plus those time bumps hurting as hell.
After few days they go away and few days later, I start all over again
Don't know what s really the problem , I have an spinal cord stimulator as well and trust me ,that's another source of heat and makes my life so confuse and never resolving that puzzle.
Hope soon to see a new dr and finally get a better treatment to treat the rash or at least ,a logic answer ,not excuses like this one : oh hi ,them system case,that as my dr way to approached me every time I saw him. the mystery case,so unprofessional and not helping in any way.
Gentle and soft hugs,take care ,Jesika .