Kawasaki Disease

What is Kawasaki disease?

Kawasaki (pronounced cow-a-SA-kee) disease is the most common cause of acquired heart disease in children. It affects about 7,000 children in the United States every year. Although most with Kawasaki disease are younger than 5 years, it can occur in children of all ages and even in young adults.

“Acquired” heart disease means it develops during childhood rather than being present at birth (congenital). No one knows what causes it.

Kawasaki disease can affect many parts of a child’s body, including the lining of the mouth, nose and throat (mucous membranes); skin; eyes; and lymph nodes (part of the immune system).

Kawasaki disease can also cause problems with the heart, including: 

  • Inflammation of a child’s blood vessels (vasculitis), especially their coronary arteries. The coronary arteries supply the heart with blood. Inflammation can lead to enlargement of these arteries called aneurysms. Then a scar can form, narrowing the arteries. In the worst case, a clot can form in the arteries and block blood flow to the heart.
  • Swelling of the heart muscle (myocarditis) or the sac around the heart (pericarditis). 

The most serious problems from Kawasaki disease are the effects it may have on the heart and its arteries. According to the American Heart Association, 1 in 5 children with Kawasaki disease have problems with their heart because of the disease.

It’s important to get care right away because treatment is much more likely to be effective if given within the first 10 days of the start of symptoms.

This disease is named after the Japanese doctor who first identified it in 1967, Tomisaku Kawasaki.

  • Kawasaki disease is the leading cause of acquired (non–birth defect related) heart disease in children in the United States. Doctors diagnose Kawasaki disease in about 7,000 children in this country each year.

    It’s not clear what causes Kawasaki disease. It is possible that infection might serve as a trigger for the body’s own immune system to attack itself. Kawasaki disease does not pass from person to person, like a virus does.

    About 1 in every 5,000 children in the United States gets Kawasaki disease. In Japan and other Asian countries, it occurs in more than 10 in every 5,000 children.

    Any child may get Kawasaki disease. It’s more common in boys and in Asian children. Most children with Kawasaki disease recover completely within weeks and do not have lasting problems. All children who’ve had this condition need to be followed and have regular check-ups to see if any problems develop. Some may need ongoing care for long-term issues.

Kawasaki Disease at Seattle Children’s


  • Our Heart Center is the top-ranked cardiology and cardiac surgery program in the Northwest and among the best in the nation, according to U.S. News & World Report. With more than 40 pediatric cardiologists, we have experience diagnosing and treating every kind of heart problem.

    Our heart team has extensive experience with the diagnosis and treatment of children with Kawasaki disease. In a typical year, we see about 40 new children with this condition. We provide ongoing care to another 500 to 600 patients with Kawasaki disease.

    Timely evaluation and treatment are essential to prevent the most serious effects of Kawasaki disease. For this reason, our Kawasaki disease specialists make seeing children with symptoms of the condition a top priority.

    Our pharmacists are experienced in safely providing and monitoring the special medicines that children with Kawasaki disease need.

    Some children need cardiac catheterization procedures to treat the narrowing of their arteries. We provide this treatment in one of our state-of-the-art cath labs and have extensive experience caring for infants, children and adolescents.

    Seattle Children’s has been treating children since 1907. Our team members are trained in their fields and in meeting the unique needs of children. For example, the doctors who give your child anesthesia (sedation) are board certified in pediatric anesthesiology. This means they have extra years of training in how to take care of kids. Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.

  • Because we see so many patients with Kawasaki disease, we have a special Kawasaki Disease Clinic within the Heart Center. The clinic is staffed by pediatric heart doctors (cardiologists) who have developed special expertise and are dedicated to the diagnosis, treatment and continuing care of patients with this condition.

    The doctors in this clinic evaluate each patient individually. They’ll review your child’s medical history and laboratory studies in order to create a specialized plan of care for your child. We will address all your questions about how this disease affects your child.

  • Seattle Children’s is also a leader for research in the causes and effective treatment of Kawasaki disease.

    Dr. Michael Portman leads a group that is working to provide new and more effective treatments, determine whether or not there is a genetic cause or a link to diet and develop a reliable test to diagnose the disease.

    Portman is directing a multicenter clinical trial to see whether using a new medicine, etanercept, with the standard medicine (intravenous immunoglobulin [IVIG] and aspirin) improves how patients do over the short and long term.

    More than 600 families have enrolled in Portman’s research to identify genetic factors that make children more likely to get Kawasaki disease or that affect how they respond to treatment.

    There is a high rate of Kawasaki disease in Asia. This has raised questions about whether soy might make children more likely to get it. Portman has published results of a study showing that eating soy isoflavone is associated with risk of Kawasaki disease. Read more about the connection between diet and Kawasaki disease.

    Read more about the Portman Research Group’s activities.

    Read more about Kawasaki disease at Seattle Children’s.

  • When you come to Seattle Children’s, a team of people will take care of your child. Along with your child’s heart doctor (cardiologist), you are connected with nurses, nutritionists, child life specialists, social workers and others, if their expertise is needed. We work together to meet all of your child’s health needs and help your family through this experience.

    We’re committed to your child’s overall health and well-being. We’ll discuss treatments in ways you can understand and involve you in every decision.

    Read more about the supportive care we offer.

Symptoms of Kawasaki Disease

Children with Kawasaki disease will usually have some or all of these symptoms: 

  • Fever higher than 101.5 degrees that lasts for at least 4 or 5 days
  • Red, patchy skin rash on the trunk and around the groin or diaper area
  • Swelling and redness in the hands and feet, with peeling skin later on
  • Red eyes, similar to pinkeye (conjunctivitis)
  • Swollen lymph nodes in the neck and armpits
  • Red, swollen, cracked lips, mouth, throat and tongue (sometimes called strawberry tongue)
  • Blood tests that show swelling (inflammation) 

Some children also get swollen joints, pain, stomachache, diarrhea and vomiting. It’s common for children to be fussy because of their symptoms.

Diagnosing Kawasaki Disease

To diagnose this condition, your doctor will examine your child and check their temperature. The doctor will ask for details about any symptoms your child has, their health history and your family health history.

There is no specific test for Kawasaki disease. Laboratory studies, such as the C-reactive protein test and a complete blood count, help to support the diagnosis.

To rule out other illnesses and to check your child’s heart, your doctor might do tests like blood tests, electrocardiogramechocardiography and chest X-rays.

Treating Kawasaki Disease

To reduce the risk of coronary artery problems, it’s important for children with Kawasaki disease to get treatment right away.

  • Intravenous immunoglobulin (IVIG), a medicine given through a vein, also called an IV, is the main treatment. It is effective if given within the first 10 days of the disease. About 20% of children do not respond to the first dose and need to get a second dose. To get this medicine, your child will need to stay in the hospital.

    Your child will also need aspirin to help control symptoms like fever, rash and swollen joints. At first, they will likely need high doses. Then, after their temperature is normal, the doctor will lower the dose. Your child will go home and stay on the lower dose for several weeks.

    Once treatment starts, children with Kawasaki disease usually start to feel much better within about a day.

    If your child has coronary artery problems from Kawasaki disease, they may need other types of care, such as medicines that prevent blood clots, to help prevent further problems.

  • No one has found an association between Reye syndrome and aspirin when used in the treatment of Kawasaki disease. Aspirin was associated with “Reye syndrome” in the 1970s and 1980s when it was used in extremely high doses to treat viral illnesses, like the flu and chickenpox.

  • Doctors at Seattle Children’s are trying to find new and better treatments for Kawasaki disease. Because 20% of children do not respond to IVIG, they are trying different medications. Your team at the hospital may ask permission for your child to participate in a clinical research study, or clinical trial, to learn more about treating Kawasaki disease. Doctors at Seattle Children’s also are searching for a way to predict which patients will not respond to IVIG. They may ask you to participate in this type of research.

    Read more about Seattle Children’s Kawasaki Disease research program.

Contact Us 

Contact the Heart Center at 206-987-2515 to request an appointment, a second opinion or more information.

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