Harlequin syndrome as a complication of epidural anesthesia.

Harlequin syndrome is a rare neurological condition that results in unilateral facial flushing and sweating. Although the syndrome is generally a benign condition with complete resolution if appropriate treatment is initiated, unilateral facial flushing can be a sign of several serious conditions and should be thoroughly investigated. Sudden onset of facial flushing related to harlequin syndrome developed in a patient who had bilateral lung transplant with postoperative epidural anesthesia for pain control. Differential diagnosis includes neurovascular disease (acute stroke), malignant neoplasm of brain or lung, Horner syndrome, idiopathic hyperhidrosis, and Frey syndrome. Harlequin syndrome is often easily treated by discontinuing the anesthetic or adjusting placement of the epidural catheter.