Chronic Regional Pain Syndrome (CRPS) also known as Reflex Sympathetic Dystrophy (RSD) is a pain syndrome that is considered more painful on the McGill University Pain Scale (42/50) than childbirth or amputation. Approximately 200,000 people in the United States suffer from this terrible syndrome. Allodynia is a common symptom of CRPS. Allodynia is pain sensitization from stimulation that is normally not painful. For instance, a mild temperature change or gentle physical touch may cause severe pain.