What is reflex sympathetic dystrophy characterized by?

Reflex sympathetic dystrophy, now more commonly referred to as complex regional pain syndrome (CRPS), is characterized by an abnormal response of the sympathetic nervous system following an injury. This condition typically occurs after an injury, surgery, or trauma and is marked by symptoms such as prolonged pain, swelling, and changes in the skin, leading to a dysfunctional response in the nervous system rather than an adequate or typical response.

The condition's hallmark is that the pain experienced is disproportionate to the severity of the initial injury, which suggests that there is a misfiring of the sympathetic nervous pathways. This miscommunication can result in increased sensitivity to stimuli, abnormal sweating, temperature changes, and skin color changes in the affected area. The abnormal sympathetic response may involve both overactivity and altered blood flow, contributing to the pain and other symptoms. Thus, option B correctly captures the essence of reflex sympathetic dystrophy by highlighting the significant role of the sympathetic nervous system's abnormal response to injury.