Reflex sympathetic dystrophy. A common clinical avenue for somatoform expression.

Reflex sympathetic dystrophy (RSD) and causalgia appear to reflect identical pictures even though the latter is related to nerve injury and the former is not. Overriding past and present skepticism about a role for the sympathetic system in their cause and treatment, the International Association for the Study of Pain still recommends sympathetic blocks and sympathectomy for both causalgia and RSD. Such fallacy is traceable to fragmentary clinical observations, to ad-hoc experiments, and to traditional neglect of the placebo phenomenon in chronic "neuropathic" pain patients.