Harlequin syndrome: An asymmetric face

Area of Science:

• Neurology
• Autonomic Nervous System Disorders

Background:

• Harlequin syndrome involves unilateral sympathetic nervous system dysfunction.
• It is typically idiopathic but can stem from other medical causes.

Observation:

• Characterized by unilateral flushing and hyperhidrosis (excessive sweating).
• Accompanied by contralateral (opposite side) hypo- or anhidrosis (reduced or absent sweating) and paleness.

Findings:

• The condition primarily affects sympathetic nerve function unilaterally.
• While often idiopathic, it can be secondary to organic compression, iatrogenic factors, or systemic diseases.

Implications:

• Harlequin syndrome poses diagnostic and management difficulties.
• Understanding its pathophysiology is crucial for developing effective therapeutic strategies.