WOW! How awful for you! Dont worry about this spreading though. Im not saying it wont, but worrying wont help u anyway. Just focus on what to do about the pain u now have. When my foot originally went haywire, i found it helpful to wear a sock because it buffered accidental stimuli from triggering pain. You might want to trycovering your arm to protect it. Keep it out of the shower, away from hot pots, etc. I broke my ankle, the same side as my rsd foot. Caused flare of rsd big time. Had to have it casted because the casual bumps or brushings of the foot would cause same old rsd searing pains. Its been a couple years and it hasnt spread any where else physically. I have developed hypothyroidism, anxiety, and some gastro intestinal disorders which i attribute to this. So take a deep breathe, hold it a few seconds, let it out slowly, and say to yourself, this too shall pass. Fingers crossed . Lol!