Does prolonged skin temperature measurement improve the diagnosis of complex regional pain syndrome?

This Practice Point provides commentary on a prospective study by Krumova et al. that explored the diagnostic utility of long-term temperature measurements in patients with upper extremity complex regional pain syndrome (CRPS). The objectives of the group were twofold: to evaluate vascular abnormalities in CRPS by comparing real-time thermal variations experienced in everyday circumstances over prolonged time frames in affected and nonaffected hands, and to develop a practical approach for differentiating CRPS from other painful conditions. Measurement of skin temperature dynamics differentiated between CRPS and arm pain secondary to other etiologies with a sensitivity of 73% and a specificity of 67%. Although the technique Krumova and colleagues used is more practical than those previously described, it is still too onerous for patients and physicians to routinely employ. We anticipate that improved identification of pain mechanisms will translate into better treatment outcomes, but this hypothesis remains to be tested.