I accidently ripped a part of my nail off my thumb recently doing a "stupid" thing. It was a horrible pain for a WEEK.

RSD is a sympathetic neuropathy, where something activates the sympathetic nervous system. There are papers showing it can be prevented (trauma and surgical trauma RSD was blocked by simple Vit C treatments). It also responds to antioxidants, and seems to be some sort of biochemical signaling error. Also there are papers that calcium channel blocking drugs can help in the early stages. This suggests a malfunction of the NMDA receptor which is activated by calcium.

There are some patients over there with a crossover to PN but not as many as you'd expect.

I do think PNers feel pain more than other people when injured. This may be more of a link to Fibromyalgia than RSD.

I placed a small strong magnet over the nerve at the base of my thumb/wrist and the pain stopped. Without that little help that thumb was throbbing away and driving me nuts, especially at night. Certain positions in bed made it far more painful. I experimented with it some, since it has been a long while since I had an accidental injury of this magnitude!