Synonyms: Progressive isolated segmental anhidrosis
Harlequin syndrome (HSD) is an autonomic disorder occurring at any age and characterized by unilateral flushing and sweating involving the face and sometimes arm and chest in condition of thermal exercise or emotional stress without sympathetic ocular manifestations. However tonic pupils parasympathetic oculomotor lesion and pre- or postganglionic sudomotor sympathetic deficit can rarely occur.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version May 2026
Newly diagnosed with
Harlequin syndrome?
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Advocacy Organizations
Dysautonomia Support Network
Dysautonomia Support Network’s Mission is to provide a Community that Empowers and Supports those impacted by dysautonomia to live their best lives. DSN provides support through community, virtual support group meetings and amazing resources such as Handouts, Handbooks and our Dyscovery Education video series.
Uganda Alliance of Patients Organization
Supporting patients to access quality, safe and patient-centered healthcare services.
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Clinical Trials
For a list of clinical trials in this disease area, please click here.