The key symptom is prolonged severe pain that may be constant. It has been described as “burning,” “pins and needles” sensation, or as if someone were squeezing the affected limb. The pain may spread to the entire arm or leg, even though the injury might have only involved a finger or toe. In rare cases, pain can sometimes even travel to the opposite extremity. There is often increased sensitivity in the affected area, known as allodynia, in which normal contact with the skin is experienced as very painful.
People with CRPS also experience changes in skin temperature, skin color, or swelling of the affected limb. This is due to abnormal microcirculation caused by damage to the nerves controlling blood flow and temperature. As a result, an affected arm or leg may feel warmer or cooler compared to the opposite limb. The skin on the affected limb may change color, becoming blotchy, blue, purple, pale, or red.
Other common features of CRPS include:
changes in skin texture on the affected area; it may appear shiny and thin
abnormal sweating pattern in the affected area or surrounding areas
changes in nail and hair growth patterns
stiffness in affected joints
problems coordinating muscle movement, with decreased ability to move the affected body part
abnormal movement in the affected limb, most often fixed abnormal posture (called dystonia) but also tremors in or jerking of the limb.