Type I complex regional pain syndrome (reflex sympathetic dystrophy) developing on the background of carpal tunnel syndrome

Complex regional pain syndrome (CRPS) is a clinical entity characterized by severe distal extremity pain as well as autonomic signs such as edema and color and skin temperature alterations. It was originally described by Weir Mitchell in 1870 as “causalgia” in order to define symptoms such as severe pain, edema, and color and temperature alterations in the distal extremities of soldiers enduring nervous injury during the American Civil War. Upon the observation of similar clinical manifestations in individuals with no nervous injury, this condition was thought to originate from sympathetic hyperactivity, hence the term “reflex sympathetic dystrophy RSD” in 1900s. More recently, the term “complex regional pain syndrome” was adopted with consensus in order to clarify the terminological controversy. While “reflex sympathetic dystrophy” defines Type I CRPS, the term “causalgia” is used for defining Type II CRPS.1