Harlequin Syndrome

What is Harlequin syndrome?

Harlequin syndrome is a condition that causes flushing and sweating on one side of your face, neck and chest. You don’t experience sweating or flushing on the other side of your body.

Harlequin syndrome affects your sympathetic nervous system. Your sympathetic nervous system is part of your autonomic nervous system. Your autonomic nervous system regulates many functions of your body that are “automatic” like your heart rate, blood pressure, breathing and digestion. Within this system is the sympathetic nervous system that’s responsible for activating your “fight-or-flight” response. This activates when your body is in motion or you feel strong emotions. Your sympathetic nervous system helps regulate your body temperature by telling your body to sweat, like when you’re exercising, to cool down. Symptoms of Harlequin syndrome appear when your sympathetic nervous system activates.

What’s the difference between Harlequin syndrome and the Harlequin sign?

Harlequin syndrome is a condition that affects your sympathetic nervous system. The Harlequin sign is a symptom of Harlequin syndrome and other health conditions. The Harlequin sign causes color changes (darkening or redness) on one side of your body. The other side will have pale or unchanged skin.

How rare is Harlequin syndrome?

It’s quite rare; fewer than 1,000 people in the United States have Harlequin syndrome.

Is Harlequin syndrome life-threatening?

No, Harlequin syndrome isn’t life-threatening. It doesn’t affect your life expectancy.

What are the symptoms of Harlequin syndrome?

Symptoms of Harlequin syndrome affect each side of your body differently. Symptoms of the affected side of your body include:

• Skin has a red tone or is darker than your natural skin tone.
• Sweating.
• Skin is warm to the touch.

On the unaffected side of your body, you may experience:

• Paleness.
• No sweating.
• Cold skin to the touch.

The sides of your body separate down the center. Imagine a line going up and down (vertically) from the center of your forehead, through your nose to your chest.

Other, less common symptoms of Harlequin symptoms include:

• Patches of scaling, dry, flaky skin.
• Headaches.
• A runny nose.
• Watery eyes.
• Droopy eyelid and/or differences in the pupils of the eye (Horner syndrome).

When do symptoms of Harlequin syndrome happen?

You may notice symptoms of Harlequin syndrome when you’re:

• Exercising.
• Feeling intense emotions or stress.
• In hot climates.
• Eating spicy foods.

What causes Harlequin syndrome?

In many cases, we don’t know what causes Harlequin syndrome. Research suggests it happens because of a miscommunication between cells on the right and left side of your body in your autonomic nervous system.

Sometimes, there’s a blockage on a cell’s communication pathway. This is the route that a cell’s message takes from your brain (hypothalamus) to the upper thoracic spinal cord. It goes out to the upper thoracic nerve roots that provide the sympathetic nerve supply to the face and upper body. It regulates your sweating and blood vessels.

The blockage could be the result of:

• A tumor along the pathway.
• A lesion from infection or inflammation.
• An injury such as from surgery in the upper chest region near your spine.

What are the risk factors for Harlequin syndrome?

Harlequin syndrome can affect anyone at any age, including babies and children. You may be more likely to develop Harlequin syndrome if you:

• Had surgery to treat excessive sweating (endoscopic thoracic sympathectomy).
• Received anesthesia.
• Experienced an injury that affected your sympathetic nervous system.
• Have an underlying condition like Horner syndrome.

What are the complications of Harlequin syndrome?

While rare, Harlequin syndrome may cause the following complications:

• Difficulty regulating your body temperature.
• Permanent facial discoloration.
• Anxiety or low self-esteem due to your body looking different.

How is Harlequin syndrome diagnosed?

A healthcare provider will diagnose Harlequin syndrome after a physical exam to review your symptoms. They’ll use tests to rule out conditions with similar symptoms and determine the underlying cause.

Tests to diagnose Harlequin syndrome include:

• Stress test: During this test, you’ll perform exercises and a healthcare provider will monitor you to see if the physical activity causes symptoms. Exercising can make symptoms of Harlequin syndrome visible.
• Imaging tests: Imaging tests give your healthcare provider a look inside your body. These tests are painless and may include a chest X-ray, computed tomography (CT) scan and magnetic resonance imaging (MRI).

How is Harlequin syndrome treated?

Treatment isn’t always necessary for Harlequin syndrome. The condition may go away on its own. If your healthcare provider recommends treatment, it depends on what caused your symptoms. Treatment could include:

• Therapy or counseling to reduce anxiety regarding how Harlequin syndrome affects your body in social situations.
• An injection of medications to block flushing or skin color changes (stellate ganglion block).
• Botulinum toxin injections to regulate sweating and other symptoms.
• Surgery or radiation to remove a tumor or lesion.

Can Harlequin syndrome be prevented?

There’s no known way to prevent Harlequin syndrome.

What can I expect if I have Harlequin syndrome?

Harlequin syndrome isn’t usually harmful to your body. Your symptoms may resolve on their own over time. Or you may only experience symptoms when you exercise or eat spicy foods. Treatment isn’t always necessary. Your healthcare provider will let you know more about your outlook and what to expect.

How long does Harlequin syndrome last?

Your symptoms can last for a few minutes to a few hours until you stop the activity that caused it. For example, if your symptoms appear during exercise, when you’re able to cool down and relax, your skin will return to normal.

When should I see a healthcare provider?

Visit a healthcare provider if you experience symptoms of Harlequin syndrome like sweating and skin color changes on only one side of your body. Harlequin syndrome usually isn’t anything to worry about. But a provider needs to diagnose its cause in the rare case it’s a sign of an underlying condition or a tumor.

What questions should I ask my healthcare provider?

• What caused my symptoms?
• Do I need treatment or surgery?
• Are there side effects of the treatment?
• What are my treatment options if I’m embarrassed about my symptoms?

Is Harlequin syndrome the same as Harlequin ichthyosis?

No. Harlequin syndrome is a condition that causes sweating and skin color changes on one side of your body. It’s not life-threatening or genetic, though many cases are present from birth (congenital).

Harlequin ichthyosis is a life-threatening, genetic skin condition. It causes a baby to be born with hard, thick skin. Babies with Harlequin ichthyosis have diamond-shaped plates on their skin. The shapes are separated by deep cracks. A healthcare provider may refer to this condition as “Harlequin baby syndrome,” which sounds like “Harlequin syndrome,” but they’re very different conditions.

A note from Cleveland Clinic

Harlequin syndrome symptoms (temporary sweating and skin color changes) only affect one side of your body. It can be difficult to feel like yourself when your skin is noticeably different than usual. A healthcare provider can help you diagnose why this is happening. In some cases, the answer isn’t always clear. Even if you don’t need treatment, you can talk to a mental health provider about ways to promote self-esteem and a positive self-image.