Kawasaki Disease

What is Kawasaki disease?

Kawasaki disease or Kawasaki syndrome is a rare type of vasculitis (blood vessel inflammation). Inflamed blood vessels can become weak and stretched out. When that happens, they’re at risk of tearing. They can also develop scarring and become too narrow. This limits how much blood can get through to nourish tissues and organs.

Kawasaki disease happens most often in children 6 months to 5 years of age. It affects all of their arteries, but the biggest concern is their coronary arteries. These supply blood to their heart. Children with affected coronary arteries can have heart issues as a result.

With prompt treatment, most children recover in about two months.

How common is Kawasaki disease?

Kawasaki disease is rare, occurring in an estimated 10 to 20 out of 100,000 children younger than 5 in the United States and Canada. In Japan, Korea and Taiwan, it affects 50 to 250 out of 100,000 children younger than 5.

Kawasaki disease is the most common cause of acquired heart disease in children in the United States, Japan and other developed countries.

What are the symptoms of Kawasaki disease?

Kawasaki disease symptoms can include:

• Fever lasting for at least five days.
• Irritability.
• Red or pink eyes without discharge.
• Redness or cracking of your child’s lips or tongue.
• Swelling and/or redness of your child’s hands or feet.
• Peeling of your child’s skin, usually beginning around their nails.
• Rash, mostly on your child’s trunk, but sometimes elsewhere.
• Swollen lymph node(s) in your child’s neck.
• Upset stomach or belly pain.

What causes Kawasaki disease?

The cause of Kawasaki disease is unknown, although more cases happen in late winter and early spring. Researchers are looking into possible Kawasaki disease causes like infections, environmental factors or genetics.

Is Kawasaki disease contagious?

No. Even though a rash is one of the symptoms, it doesn't spread through person-to-person contact.

What are the risk factors for Kawasaki disease?

Risk factors for Kawasaki disease include:

• Male sex.
• Being younger than age 5.
• Being of Pacific Islander or Asian descent.

You can still get Kawasaki disease even if you don’t have any of these risk factors.

What are the complications of Kawasaki disease?

Complications of Kawasaki disease include:

• Aneurysms (weakness or stretching) in inflamed coronary arteries. In severe cases, this may require coronary artery bypass surgery.
• Blood clots and narrowing in coronary arteries.
• Coronary artery rupture.
• Issues with the heart valves that help blood move through your child’s heart.
• Inflammation in your child’s heart.
• Hepatitis in your child’s liver.
• Inflammation in your child’s lungs.
• Infections in your child’s heart.
• Pancreatitis (inflammation) in your child’s pancreas.
• Poor heart function or heart failure.
• Heart attack.

How is Kawasaki disease diagnosed?

Symptoms and signs help healthcare providers make a Kawasaki disease diagnosis with a physical exam. If your child only has some of the symptoms, this is atypical or incomplete Kawasaki disease. Before making a diagnosis, providers have to rule out other causes of fever.

What are the three stages of Kawasaki disease?

The three stages of Kawasaki disease are:

Stage 1 (Acute)

• Fever for five days or more.
• Rash around the trunk or groin.
• Pink eye.
• Red tongue and lips.
• Red skin on hands and feet (palms and soles).
• Swelling in lymph nodes.

Stage 2 (Subacute)

• Starts when fever goes away.
• Upset stomach.
• Diarrhea.
• Pain in joints and belly.
• Peeling skin on hands and feet.

Stage 3 (Convalescent)

• Symptoms go away slowly, but complications can continue.

What tests will be done to diagnose Kawasaki disease?

There’s no test that can directly detect Kawasaki disease. But healthcare providers can do tests that support a diagnosis of Kawasaki disease or rule out other possible illnesses.

They may order:

• Blood tests.
• Urinalysis.
• Echocardiogram, which uses an ultrasound wand on the surface of the chest to view your child’s heart and arteries.
• Electrocardiogram (EKG), a noninvasive test that measures the rhythm in your child’s heart.
• CT (computed tomography) angiogram, using X-rays and a computer.
• MRA (magnetic resonance angiogram), using an MRI.

How is Kawasaki disease treated?

Treatment for Kawasaki disease includes:

• Immune globulin (IVIG), or human blood proteins you receive by IV. About 10% of children may not respond to the first dose of IVIG and will need a second dose or other medications.
• Aspirin.
• IV fluids for hydration.
• Medications for pain and swelling.
• Anticoagulants (blood thinners) for people at risk of blood clots.
• Steroids or other anti-inflammatory medications in severe cases.
• Cold compresses.

Your child will be in the hospital for treatment. The goals of Kawasaki disease treatment are to:

• Reduce inflammation.
• Prevent or lessen damage to arteries.
• Prevent blood clots in people with coronary artery issues.
• Prevent heart complications.

Complications/side effects of the treatment

IVIG is usually well tolerated, but can cause:

• Hemolytic anemia (red blood cells die faster than normal).
• Infusion reactions.
• Chest pain.
• Difficulty breathing.
• Upset stomach.
• Pain in muscles or joints.

Anticoagulants can make your child bleed more easily.

Can Kawasaki disease be prevented?

No. Because researchers don’t know what causes Kawasaki disease, they don’t know how to prevent it.

What can I expect if my child has Kawasaki disease?

The reasons for admission vary, but evaluation for Kawasaki disease usually takes place in the hospital.

Your child will be ready to go home from the hospital when they’re:

• Drinking fluids.
• Taking medicines by mouth.
• No longer have a fever or signs of inflammation.

You’ll need to follow up with your primary healthcare provider, an infectious disease doctor and a cardiologist after discharge. They’ll follow your child closely, including repeating lab work, until there’s no longer any need for further therapy.

A cardiologist will order follow-up echocardiograms one to two weeks and four to six weeks after hospital discharge. Your child may need more frequent echocardiograms if they had issues with their coronary arteries.

Does Kawasaki disease ever go away?

Children can have Kawasaki disease symptoms for four to six weeks. They may feel tired and irritable for eight weeks.

Kawasaki disease can come back in about 2% or 3% of cases.

It can cause long-term damage to arteries and possible heart issues in adulthood. Atherosclerosis is one example. People who have aneurysms (dilated coronary arteries) from the disease need long-term follow-up every year or a few years for the rest of their lives. In some cases, they may need a procedure to improve blood flow.

Your child’s provider will want to make sure they don’t develop blood clots. They also want to make sure your child’s heart muscle gets enough oxygen.

Outlook for Kawasaki disease

The outlook for children with Kawasaki disease depends on how much it affects their hearts. Complications that affect their heart can be severe enough to be fatal within 15 to 45 days of a fever starting. Fortunately, treatment can usually keep heart disease from occurring.

Coronary artery aneurysms can happen in 25% of people who don’t get treatment. In children who receive timely treatment, the rate of coronary artery aneurysms is less than 6%. With treatment, 50% of children with affected coronary arteries heal in one to two years.

Is Kawasaki disease serious?

Yes. But with prompt treatment, most children with Kawasaki disease can recover completely.

How do I take care of my child?

You can care for your child by:

• Ensuring your child’s vaccinations are up to date, including COVID-19, influenza and varicella, while they’re taking aspirin. There’s a small risk of Reye's syndrome in children who take aspirin with a viral illness.
• Not giving your child live virus vaccines (for example, the measles-mumps-rubella, varicella and the nasal live virus influenza vaccines) for 11 months following IVIG. This is because the IVIG may interfere with their body’s ability to develop antibodies to these viruses.
• Restricting certain activities if your child has abnormalities on their echocardiogram.

When should my child see their healthcare provider?

Contact your healthcare provider if your child has:

• A fever that comes back.
• Severe joint pain.
• Any return of previous symptoms that are getting worse.

What questions should I ask my doctor?

Questions to ask your provider include:

• How severe is my child’s condition?
• How long do you expect them to be in the hospital?
• Is there a support group for parents of children with Kawasaki disease?
• How much should I restrict my child’s activity?