Recurrence of complex regional pain syndrome after administration of adenosine

Background: The effects of adenosine in acute chronic pain are not clear. Literature supports both a pronociceptive/inflammatory role of the A2aR/A2bR and antihyperalgesia/allodynia with A1Rs/A3Rs. Adenosine could participate in the reactivation of chronic regional pain syndrome (CRPS) through inflammatory pathways and via A2Rs. Plastic changes in the brain CRPS-related overlap with those seen in systemic inflammation and persist even after symptoms of CRPS resolve. Aim: To illustrate the hypothesis that intravenous adenosine can reactivate dormant CRPS. Case report: An individual with successfully treated CRPS developed supraventricular tachycardia, he was treated with intravenous adenosine. Shortly after a second dose, he developed severe pain at a lower limb from relapsed CRPS. Treatment included lumbar sympathetic block, physical therapy and pharmacological agents. Conclusion: Intravenous adenosine can reactivate dormant CRPS. Its potential pronociceptive role in CRPS calls for further studies to better elucidate the underlying mechanisms.