Complex Regional Pain Syndrome: The Worst Pain Known to Humankind

Complex regional pain syndrome (CRPS) is the worst pain known to humankind. It has been classified as pain worse than cancer pain, amputation of a digit, or labor pain. The difference is that CRPS is a chronic condition that lasts for many years. As in all medical conditions, the essential piece to diagnosis of CRPS is based on the clinical history and physical examination. The diagnosis of CRPS depends on the following: pain, color and temperature asymmetry, swelling, and nail and hair growth changes. The intensity of the pain is far more than expected from the inciting injury and in some cases from immobilization. The pain spreads to a wider area than the original site. It may spread to the opposite side and even to the whole body, including the viscera. The pain is unrelated to any physical activity but does increase significantly with using the body part. A color differential between the affected and the unaffected side is often very obvious but may not be present continuously. A temperature differential of 1.1ºC between the affected and the unaffected side is considered significant. The color and temperature differential is not as obvious in the torso or the axial skeleton as in CRPS of the abdomen, perineum, or chest wall. The swelling is much more evident in the initial stages of the condition and can vary from a small area of pitting edema to large diffuse swelling to the point of skin becoming thin and glossy and even breaking down. Hair changes may consist of darker, coarser hair or light and sparse hair. Nails may be brittle, discolored, and ridged. There is no gold standard test to diagnose CRPS. Testing may be done to rule out another possible diagnosis.