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Genetic and Rare Diseases Information Center (GARD)

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Harlequin syndrome

Other Names for this Disease
  • Sudden onset of unilateral flushing and sweating
  • Unilateral loss of facial flushing and sweating with contralateral anhidrosis
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What is Harlequin syndrome?

Harlequin syndrome was first coined by Lance and Drummond in 1988 when they described five cases of unilateral (on one side) flushing and sweating.[1] The asymmetrical facial sweating and flushing described with this condition has been named the 'Harlequin Sign'.
Last updated: 6/29/2009

What symptoms are associated with Harlequin syndrome?

The Harlequin sign is sometimes associated with warmth and anhidrosis (lack of sweating) of the arm and leg on the opposite side. This may be induced by exercise.  Attacks of cluster headache may be accompanied by tearing and nasal discharge, forehead sweating, and abnormal contraction of the pupils and drooping of the upper eyelid. The cause of these phenomena has no widely accepted explanation.[2]
Last updated: 6/29/2009

What causes Harlequin syndrome?

Most cases of Harlequin syndrome are thought to occur when nerve bundles (particularly ones in the face and neck) are injured. In many cases, the cause of the injury is unknown. However, individual cases of Harlequin syndrome have been reported in association with: trauma, tumor, stroke, autoimmune disease (multiple sclerosis), syringomyelia, hygroma, neurinoma, optic neuritis, and parasomnia. Signs and symptoms of Harlequin syndrome may overlap with those of Ross syndrome, Adie syndrome, and Horner's syndrome.[3][4]
Last updated: 12/28/2012

Is there treatment for Harlequin syndrome?

In individuals who have the Harlequin sign with no known explanation, no treatment is usually required, and the condition is benign.[5]
Last updated: 6/29/2009