Reflex sympathetic dystrophy R.S.D or Complex regional pain syndrome:

Complex regional pain syndrome or RSD is essentially inflammation of the autonomic nerves in a localized area. RSD has been associated with injury dating back to the Civil War. We have already described the association of autoimmune disorders with injury. In general, patients who have complex regional pain syndrome suffer from pain, sensory changes, edema, sweating, and temperature disturbance in the afflicted extremity. Chronic changes can involve the skin, nails, and bone. Persistent inflammation, of the sympathetic nervous system and the central nervous system causes this condition.

Symptoms include increased sweating, skin color changes, skin temperature changes, weakness of the affected area, swelling, as well as symptoms outside the affected dermatome.