An old lady with anterior chest pain and unilateral facial flushing.

Harlequin syndrome is rare and typically characterized by asymmetric flushing and sweating. Although it is usually considered idiopathic, literature review shows that it may be caused by lesion over lung apex or after central venous catheterization in the internal jugular vein. We present a 74-year-old woman who had been experiencing recurrent chest pain and right shoulder pain since 2 weeks ago.