Harlequin syndrome

What causes Harlequin syndrome?

Most cases of Harlequin syndrome are thought to occur when nerve bundles, particularly ones in the head and neck, are injured. Nerve bundles allow signals from the autonomic nervous system to travel throughout the body. In many cases, the cause of the injury to the nerve bundles is unknown. However, individual causes of the symptoms of Harlequin syndrome have been reported in association with: trauma, tumor, stroke, autoimmune disease (multiple sclerosis or hyperthyroidism), a virus, or a fluid-filled cyst in the spinal cord (syrinx).

When the nerve bundles are injured, they are not able to communicate with half of the face and body properly. Therefore, that half of the body is not able to respond to stimuli such as exercise by flushing and producing sweat. This causes the Harlequin sign that is associated with this syndrome.

Last updated on 05-01-20

How is Harlequin syndrome diagnosed?

A diagnosis of Harlequin syndrome is typically made when a person has symptoms consistent with the condition. This may include clinical evaluation after exercise and a sweating test to determine which parts of the body are affected.

If Harlequin syndrome is suspected, other tests may be ordered to rule out other symptoms associated with the syndrome or other diseases with similar symptoms. These tests may include an MRI of the spine and brain to determine if there is a visible cause of the symptoms. Doctors may also want to see if there are any symptoms affecting the pupils of the eyes and the reflexes elsewhere in the body.

Last updated on 05-01-20

Is Harlequin syndrome inherited?

Harlequin syndrome does not appear to be inherited from one generation to the next. In most cases, Harlequin syndrome is thought to be caused by injury to the nerve bundles, which cannot be inherited from a parent. However, in some cases Harlequin syndrome seems to be associated with autoimmune disease, which could be caused by the immune system attacking the nerve bundles as if they were an infection.

In general, autoimmune diseases are thought to be caused by a combination of genetic and environmental factors. If Harlequin syndrome is caused by an autoimmune response, it is possible that the symptoms of Harlequin syndrome could occur in other members of the family with an autoimmune disease.

Last updated on 05-01-20

Do people with Harlequin syndrome feel a sensation when their face begins to flush?

Yes. People with Harlequin syndrome may feel a sensation with facial flushing.

Last updated on 05-01-20

Is Harlequin syndrome a progressive disease? Can the facial flushing become constant?

Signs and symptoms of Harlequin syndrome very rarely progress. The syndrome tends to have a stable course. We were unable to find a case report describing an individual with Harlequin syndrome that experienced constant facial flushing.

Last updated on 05-01-20

How rare is Harlequin syndrome?

We are not aware of a prevalence or incidence estimate for Harlequin syndrome. It is generally considered a rare condition due to the paucity of case reports.

Last updated on 05-01-20

Is Harlequin syndrome genetic or does it occur secondary to an abnormality in embryonic/fetal development?

Harlequin syndrome is not a genetic disorder. Most cases 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.

Last updated on 05-01-20

What is the long-term outlook for people affected by Harlequin syndrome?

The long-term outlook for people affected by Harlequin syndrome is good. This syndrome is known as a benign condition because it is not known to affect a person’s daily living or lifespan. However, for some people the facial flushing and sweating associated with Harlequin syndrome may be embarrassing. These individuals may desire treatment.

It is important to determine if there is another underlying cause of the symptoms in order to receive proper treatment and accurately predict a person’s long-term outlook.

Last updated on 05-01-20

Is there treatment for Harlequin syndrome?

If an underlying cause of Harlequin syndrome is identified, treatment should be directed to the cause of the syndrome. Surgery may be possible to repair a lesion that is causing Harlequin syndrome. If there is no known cause of the symptoms and the symptoms are not affecting a person’s daily life, some people may choose not to pursue any treatment.

In cases where an individual has symptoms of Harlequin syndrome and wishes to receive treatment, injection with botulinum toxin (Botox) or a procedure called contralateral sympathectomy is possible. In contralateral sympathectomy, the nerve bundles that are responsible for causing flushing in the face are interrupted. Therefore, this procedure causes both sides of the face to no longer flush or sweat. Because the symptoms of Harlequin syndrome are not typically associated with affecting a person’s daily life, this treatment is only recommended if a person is very uncomfortable with the flushing and sweating associated with the syndrome.

Last updated on 05-01-20

McDougal DH and Gamlin PD. Autonomic control of the eye Comprehensive Physiology. January 2015; 5(1). 439-473. Reference Link Corbett M and Abernethy DA. Harlequin syndrome J Neurol Neurosurg Psychiatry. 1999; 66(4). 544. Reference Link Tascilar N, Tekin NS, Erdem Z, Alpay A, and Emre U. Unnoticed dysautonomic syndrome of the face: Harlequin syndrome Autonomic Neuroscience: Basic and Clinical. December 30, 2007; 137(1-2). 1-3. Reference Link Biondi A, Persiani R, Zoccali M, Rausei S, Cananzi F, and D'Ugo D.. Harlequin syndrome Ann Thorac Surg. July 2009; 88(1). 304. Reference Link Fallon KE and May JJ. Harlequin syndrome in two athletes Br J Sports Med. 2005; 39. e1. Reference Link Pavone P, Praticò AD, Micali G, Greco F, Ruggieri M, and Pavone L. Autonomic Dysfunction Manifesting With Asymmetric Face Flushing and Paroxysmal Nonconvulsive Episodes J Child Neurol. December 2013; 28(12). 1673-1676. Reference Link Algahtani H, Shirah B, Algahtani R, and Alkahtani A. Idiopathic Harlequin syndrome manifesting during exercise: A case report and review of the literature Case Reports in Medicine. 2017; 2017. Reference Link de Avelar Breunig J, Hartmann M, Freire CF, and de Almeida HL. Harlequin syndrome in childhood—case report Anais Brasileiros de Dermatologia. November-December 2012; 87(6). 907-909. Reference Link Pradeep PV, Benede AK, Harshita SS, and Jayashree B. Harlequin syndrome in a case of toxic goiter: a rare association Case Reports in Medicine. 2011; 2011. Reference Link Harlequin syndrome Orphanet. Reference Link

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