Vol. 46 No. 1 (2026): Le syndrome d’Arlequin : revue de la littérature et cas clinique

Harlequin syndrome is a rare facial dysautonomic disorder first described in 1988 by Lance. The syndrome is characterized by erythematous dyschromia with hemifacial hyperhidrosis. Dyschromia and hyperhidrosis are well-defined at the midline and are also associated with contralateral anhidrosis. The condition results from unilateral disruption of sympathetic fibers at the level of vertebrae T2-T3. In most cases, the condition is idiopathic. However, several cases secondary to underlying cervical and upper thoracic pathologies, to cervico-thoracic surgical or anesthetic interventions, or to systemic diseases have been reported in the literature. Although it is a benign syndrome that often resolves spontaneously, its sudden, dramatic, and colorful onset can cause significant distress and anxiety for the patient and their family. A proper understanding of this syndrome enables clinicians to identify the condition and guide appropriate management.