Harlequin Sign

Overview

Harlequin sign is a noticeable difference between the two sides of the face or body. One side may look red and sweaty, while the other side looks pale and dry. In newborns, it is usually a harmless, temporary color change. In older children and adults, it can be a sign related to the nerves that control blood vessels and sweat glands. It is not a disease itself, and it is not contagious.

The newborn color change is common and usually harmless. The pattern of one-sided flushing and sweating in older children or adults is rare.

The newborn form is seen in babies, often in the first few days of life. The one-sided flushing and sweating form can affect children and adults of any age. It is sometimes called Harlequin syndrome when it causes repeated one-sided flushing and sweating.

Symptoms

Common symptoms

• One side of the face becomes red and sweaty while the other side stays pale and dry.
• The difference may be more noticeable after heat, exercise, strong emotion, or a hot shower.
• Some people notice only flushing, only sweating, or both.
• The skin color difference may come and go, and it usually does not hurt.
• The pattern can be noticed by other people, which may feel embarrassing.

Symptoms in children

• In newborns, a temporary sharp line can appear between pink or red skin on one side of the body and pale skin on the other side.
• The newborn color change is often brief and goes away on its own.
• Older children can have the same one-sided flushing and sweating pattern as adults.
• If a child has new one-sided symptoms with eye changes, weakness, or feeling unwell, seek medical advice.

Symptoms in older adults

• New one-sided flushing or sweating in an older adult deserves a check, especially if it starts suddenly.
• It may be noticed along with a drooping eyelid, a smaller pupil, eye pain, or vision changes.
• Many causes are not serious, but a healthcare professional can help decide whether tests are needed.

Causes

Main causes

• In newborns, the color change is thought to be due to immature control of blood vessels and usually settles without treatment.
• In older children and adults, it can be linked to the nerves that control blood vessels and sweat glands, sometimes called the sympathetic nerves.
• Sometimes no clear cause is found, and the pattern is harmless.
• Less often, it may be linked to nerve irritation, nerve injury, neck or chest surgery, eye problems, or other underlying conditions.

Risk factors

• Being a newborn, for the harmless newborn color change.
• Having had neck, chest, or eye surgery or an injury in those areas.
• Having a condition that affects the nerves controlling the face or eyes.
• Rarely, having a growth or other problem near nerve pathways, which is why new symptoms are checked.

When to see a doctor

See a doctor urgently if:

• Call your local emergency number for sudden weakness, facial drooping, trouble speaking, vision loss, severe headache, seizure, fainting, chest pain, or breathing trouble.
• Seek same-day medical advice for new one-sided flushing or sweating with eyelid drooping, pupil changes, eye pain, or vision changes.
• Seek same-day advice if a baby with a color change seems unwell, is not feeding, or is unusually sleepy.
• Get checked quickly if symptoms start after a neck, chest, or eye injury or surgery.

Book a routine appointment if:

• Make a routine appointment if one-sided flushing or sweating keeps happening and you want to know why.
• See your doctor if the visible difference bothers you or affects your confidence.
• Ask about a check-up if a newborn color change lasts longer than expected or you are unsure.

Diagnosis

A healthcare professional usually starts by asking about when the symptoms happen, what triggers them, and whether both sides of the face or body are affected. They will examine you or your child, including the eyes and nerves. There is no single test for Harlequin sign. Tests are used only when needed to look for an underlying cause.

Tests that may be done

• Physical and neurological examination.
• Eye examination, including pupil checks.
• Blood tests if an underlying condition is suspected.
• Imaging such as ultrasound, CT, or MRI in some cases.
• Specialist tests of sweating or nerve function, usually only if referred to a specialist.

What to expect at your appointment

Your clinician may ask you to keep a simple diary of when the flushing or sweating happens. If symptoms are mild and clearly linked to heat or exercise, you may only need reassurance. If there are eye or nerve symptoms, you may be referred to a specialist for further checks.

Treatment

For the newborn color change, no treatment is needed. For older children and adults, treatment depends on whether an underlying cause is found and how much the symptoms bother you. Many people need only reassurance and simple ways to avoid triggers.

Self-care at home

• Keep cool and avoid overheating. Use fans, loose clothing, and cool drinks in hot weather.
• Notice and avoid triggers such as very hot rooms, heavy exercise, or stressful situations when possible.
• Keep a simple diary of when symptoms happen and share it with your healthcare professional.
• For a baby, mention any color changes at check-ups. Seek advice if the baby seems unwell.
• Use gentle, unscented skin care if sweating irritates the skin.

Medical treatments

If an underlying condition is found, the focus is on treating that condition. For bothersome flushing or sweating, specialists may discuss options such as procedures that reduce nerve signals, but these are not suitable for everyone and are only considered after a full assessment. Your healthcare professional can explain what is safe and appropriate for you.

When is surgery considered?

Surgery is not usually needed for Harlequin sign itself. It may be considered only if a treatable underlying cause is found, and any decision would be made with specialist advice.

Living with this condition

Most people manage by avoiding overheating and knowing that the pattern is usually harmless. If the visible difference makes you self-conscious, it is okay to talk about it with your doctor or someone you trust.

Lifestyle tips

• Stay cool in hot weather and during exercise.
• Drink enough fluids, especially when you are warm or active.
• Manage stress with relaxed breathing, gentle activity, or hobbies you enjoy.
• Build exercise up gradually and choose cooler times of day.
• Ask for adjustments at work or school if heat or embarrassment is a problem.

Diet and exercise

There is no special diet for Harlequin sign. Regular exercise is usually fine. Choose cooler times, keep water handy, and stop if you feel dizzy, faint, or unwell.

Mental health and emotional wellbeing

A visible one-sided color or sweating pattern can cause embarrassment, worry, or low confidence. These feelings are valid, and support is available. If you feel overwhelmed or have thoughts of harming yourself, contact your local emergency number or a local crisis support service right away.

Prevention

The newborn form cannot be prevented. The one-sided flushing and sweating form is not always preventable, but avoiding triggers may reduce episodes. Treating any underlying condition can help.

Vaccines

There is no vaccine that prevents Harlequin sign.

Screening programmes

There is no routine screening test for Harlequin sign. New one-sided symptoms should be checked by a healthcare professional.

Complications

If left untreated

• The newborn color change usually goes away on its own with no lasting effects.
• If an underlying nerve or eye condition is present, symptoms may continue or change over time.
• Rarely, a more serious underlying cause may need treatment.
• Some people feel embarrassed or anxious about the visible symptoms.

Long-term outlook

The outlook is very good for the newborn form, which is harmless and temporary. For older children and adults, many cases are not serious and can be managed with simple measures. A check-up helps rule out other conditions and gives you clear guidance.

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