Classification of complex regional pain syndromes. New concepts.

A new classification system, termed complex regional pain syndromes types I and II, has been devised to replace the nomenclature of pain disorders previously termed reflex sympathetic dystrophy and causalgia. CRPS type I does not have identifiable major nerve injury, whereas CRPS type II has an identifiable major nerve injury. The classification is based on clinical symptoms and signs without incorporating any mechanistic connotations. These CRPS disorders may have SMP, SIP, or both.