Is complex regional pain syndrome a neuropathic pain state?
Proposed mechanisms of CRPS include neurogenic inflammation, altered blood flow due to efferent sympathetic activity, cortical reorganization, and autoimmunity. Although the precise mechanism or group of mechanisms is unknown, CRPS shares some clinical and pathologic features with neuropathic pain states. In particular, people with CRPS demonstrate exquisite allodynia and hyperalgesia, and skin biopsy in CRPS demonstrates reduced ENF density. That said, CRPS is a very distinct clinical entity and the trophic changes, temperature changes, and severity of cutaneous sensitivity and guarding make it clearly different from other neuropathic pain states.