Reflex sympathetic dystrophy and burning neuralgia: This is a chronic pain state. Those caused by bone or soft tissue injury are called type I complex localized pain syndrome (CRPS), or reflex sympathetic dystrophy; those caused by nerve injury are called type II CRPS, or burning neuralgia. Pain is associated with autonomic changes (e.g., impaired sweating or vasomotor disorders) and/or nutritional changes (e.g., skin or bone atrophy, hair loss, joint contractures). Radionuclide bone scans (showing elevated uptake), radiographs of the limbs (showing bone sparing), and thermography (showing elevated or decreased skin temperature) are useful in uncovering autonomic changes and trophic changes. Complex localized pain syndromes primarily involve sympathetically maintained pain, rather than other types of chronic pain. Therefore, if this syndrome is suspected, treatment with blockade of sympathetic efferent function should be used, usually with a nerve block or closure. Some clinical observations suggest that the outcome can be improved if sympathetic nerve closure is administered as early as possible. Treatment: If the syndrome is maintained by sympathetic nerves, narcotic or pharmacological closure of sympathetic function and physical therapy are the most important treatment measures. If not, interventions targeting the sympathetic nervous system should not be pursued. If pain relief remains relatively short-lived despite repeated temporary closure, surgical or chemical sympathectomy is indicated. In elective cases, the application of intravenous guanethidine, reserpine, or brompheniramine for local sympathetic closure, a specific anesthetic technique, may be useful. The sympathetic blocking drugs prazosin (1-8 mg total daily in divided oral doses) and phenoxybenzamine (40-120 mg total daily in divided oral doses) may also be helpful. Other drugs that may be tried are nifedipine (10-30 mg orally, 3 times daily), adrenocorticosteroids (e.g., prednisone, 60-80 mg total orally daily, tapered to discontinuation over 2-4 weeks), tricyclic antidepressants, anticonvulsants, and other drugs used to treat any type of neuropathic pain (see above). Long-term use of opioid analgesics is of varying opinion but is occasionally useful in reliable patients; however, this treatment should be considered only after all other applications have failed and close follow-up observation of the patient is required. Physical therapy is important in all phases of treatment. If a myofascial pain provocation site is found, local anesthetic or saline injection should be considered. Transcutaneous electrical current nerve stimulation may be helpful and should be explored over a long period of time for different stimulation sites with different stimulation parameters. Other methods of nerve stimulation (nerve reinforcement) include stimulation resistances (short rubs to the damaged painful area) and acupuncture treatment. There are no studies to clarify which neurostimulation treatment is superior to another, nor can it be concluded that if one method does not work well, applying another method will not work either. In short, treatment is all empirical. Psychotherapy is discussed below.