Harlequin Syndrome Related to Perioperative Intercostal Blockade: A Case Report.

Harlequin syndrome is a rare syndrome characterized by hemifacial flushing and altered facial sweating, with only a few case reports related to intercostal blockades. We present a case of Harlequin syndrome in a 65-year-old woman after intercostal blockade for video-assisted thoracoscopic lobectomy. One hour postoperatively, the patient became nauseated and presented with flushing of the right half of the face with a clear line of demarcation. Within 3 hours, the flushing disappeared. In this case report, we discuss Harlequin syndrome in relation to intercostal blockade and encourage clinicians to consider this syndrome in the differential diagnosis when encountering similar symptoms.