Bisphosphonates for pain relief in reflex sympathetic dystrophy

Reflex sympathetic dystrophy (RSD) is a poorly characterised condition whose various and unpredictable features include pain, tenderness, swelling, vasomotor, and sudomotor changes, involuntary movements, and trophic phenomena. 1 Also known by terms such as algodystrophy, Sudeck’s atrophy, and complex regional pain syndrome (CRPS) type I, RSD most commonly follows trauma and is distinguished from causalgia (CRPS type II), which is associated with major nerve injury. The pain of RSD may have various qualities but is typically burning, spreads outside the area that has been damaged, and is often accompanied by sensory features, including allodynia and hyperalgesia.Osteoporosis is one of its diverse trophic features.It characteristically spares the articular surfaces and may be spotty, focal, or more widespread than at the site of the causative lesion. 1 First recognised radiographically in 1900 by Sudeck, 2