Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to obtain a history from you and examine you, I can not comment on a formal diagnosis or treatment plan for your symptoms. However, I will try to provide you with some information regarding this matter.
Reflex sympathetic dystrophy (RSD) is now referred to as Complex Regional Pain Syndrome (CRPS). Complex regional pain syndrome is a condition that is usually due to a soft tissue injury. Associated symptoms include abnormal skin color or temperature changes, abnormal sweating, and/or swelling of the affected extremity. The exact pathophysiology is unclear. It is likely due to an abnormal reflex arc from the sympathetic nervous system modulated by cortical pain centers, e.g., brain, causing an increase in catecholamine hypersensitivity. This latter statement is important because the emotional disturbance caused by the injury in many patients may be a precipitating factor in the pain syndrome. A concept that should be mentioned is that of central and peripheral sensitization. These concepts explain the lowering of the pain threshold and can explain why patients feel pain to nonpainful stimuli. The treatment is multifactorial and should begin with neuropathic treatment (see below).
The pain associated with nerve irritation is called "neuropathic pain", and specific medications are effective in this type of pain. Examples of these include (but are not limited to) anti-seizure medications such as Neurontin (Gabapentin) and Lyrica (Pregabalin), and antidepressant medications such as Elavil (Amitriptyline). While medication over time can help lessen the pain associated with complex regional pain syndrome, other treatments such as physical therapy and swimming are often more helpful than you might think. The goal with these treatments is to allow a patient to return as close to normal function as possible, and minimize long-term disability. Often strong narcotic and anti-inflammatory medications are used to treat acute pain, which is appropriate just after an injury, or for re-injury. However, if your doctor has diagnosed your mother with complex regional pain syndrome, then strong narcotics are not likely to help, and may have serious side effects.
I would recommend your mother see a chronic pain specialist. These specialists can be found in many large academic centers in the pain management departments. They may either be an anesthesiologist, psychiatrist, or neurologist, and they can help refer your mother to the other necessary therapies.
Thank you for using the forum, I hope you find this information useful, good luck.