What clinical sign of complex regional pain syndrome (CRPS) indicates sensory perception abnormalities?

Unrelenting burning pain is a key clinical sign of complex regional pain syndrome (CRPS) that indicates sensory perception abnormalities. Patients with CRPS often experience pain that is disproportionate to the initial injury or trauma, which is characterized by a burning or aching sensation that can be constant or intermittent. This type of pain is not just a physical response but reflects alterations in the nervous system, particularly in sensory pathways.

In CRPS, the pain arises from nerve damage or abnormal activity within the nervous system, which leads to a heightened sensitivity to pain stimuli (hyperalgesia) and an abnormal response to normally non-painful stimuli (allodynia). This burning pain can feel overwhelming and is a significant aspect that affects the patient's quality of life.

Other options including persistent muscle fatigue, joint stiffness, and loss of limb flexibility are symptoms that may be associated with CRPS but do not directly indicate the sensory perception abnormalities as clearly as the unrelenting burning pain does. These other signs are more related to immobilization, disuse, or muscle involvement rather than the distinct sensory experiences of pain perceived in CRPS.