Recurrence of complex regional pain syndrome after administration of adenosine.

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. To illustrate the hypothesis that intravenous adenosine can reactivate dormant CRPS. 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. Intravenous adenosine can reactivate dormant CRPS. Its potential pronociceptive role in CRPS calls for further studies to better elucidate the underlying mechanisms.