A pediatric case of idiopathic harlequin syndrome

Harlequin syndrome is a rare condition characterized by asymmetric facial flushing and sweating in reaction to heat, exercise, or emotional circumstances. It results from a defect of the autonomic nervous system. The syndrome can arise from structural defects or iatrogenic factors or can be primary (idiopathic) and have a benign course. We report a 4-year-old boy who experienced sweating and flushing on the left side of the face after exercise. He had no noteworthy medical or birth history. Neurological and ophthalmological examinations revealed no additional abnormalities. Magnetic resonance imaging of the cervicothoracic spinal cord and cerebrum showed no anomalies. A diagnosis of idiopathic harlequin syndrome was made.