Diagnostic criteria in patients with complex regional pain syndrome assessed in an out-patient clinic

Background: Specific criteria have been described and accepted worldwide for diagnosing patients with complex regional pain syndrome (CRPS). Nevertheless, a clear-cut diagnosis cannot be confirmed in a number of cases. Aim: The objective of this study was to investigate the effectiveness of the described diagnostic criteria used by several clinical disciplines. Methods: We included 195 patients who were referred to our pain clinic within a period of 1 year. Data were collected on patient characteristics, signs, symptoms, disease-related medication, and the background of the referring clinicians. Results: The Harden and Bruehl criteria were confirmed in 95 patients (49%). These patients used a higher than average number of analgesics, opiates, and anti-oxidants, and frequently received prescriptions for benzodiazepines instead of anti-depressants. The mean disease duration was 29 ± 4.6 months and the mean visual analogue score for pain was 8.1 ± 0.19. A subgroup of patients had a colder temperature in the affected extremity compared with the unaffected extremity. This subgroup showed a longer disease duration and higher visual analogue scale pain. Conclusion: The diagnostic criteria used to determine CRPS should be further improved. A large number of referred patients experienced substantial pain, without receiving adequate medication. Disease-related medication is unrelated to CRPS-specific disease activity. Knowledge of underlying mechanisms is warranted before an adequate pharmaceutical intervention can be considered.