What Is Kawasaki Disease?

Kawasaki (KAH-wah-SAH-ke) disease is a rare childhood disease. It's a form of a disease called vasculitis (vas-kyu-LI-tis).

In Kawasaki disease, the walls of the blood vessels throughout the body become inflamed. The disease can affect any type of blood vessel in the body, including the arteries, veins, and capillaries.

In some cases, Kawasaki disease affects the coronary arteries, which carry oxygen-rich blood to the heart. As a result, a small number of children who have Kawasaki disease may develop serious heart problems.

Overview

The cause of Kawasaki disease isn't known. The body's response to a virus or infection combined with genetic factors may cause the disease. However, no specific virus or infection has been found, and the role of genetics isn't known.

The disease can't be passed from one child to another. Your child won't get it from close contact with a child who has the disease. Also, if your child has the disease, he or she can't pass it on to another child.

Kawasaki disease affects children of all races and both genders. It occurs most often in children of Asian and Pacific Island descent. It's more likely to affect males, and most cases occur in children younger than 5 years.

One of the main symptoms of this disease is a fever that lasts longer than 5 days. The fever remains high even after treatment with standard childhood fever medicines. Children with the disease also may have red eyes, red lips, and redness on the palms of their hands and soles of their feet. These are all signs of inflamed blood vessels.

Early treatment is important. It helps reduce the risk that Kawasaki disease will affect the coronary arteries and cause more serious problems.

Outlook

Kawasaki disease can't be prevented. However, most children who develop Kawasaki disease fully recover—usually within weeks of getting symptoms. Further problems are rare.

In some children, the disease affects the coronary arteries. This can cause serious problems. These children need long-term care and treatment.

Researchers continue to look for the cause of Kawasaki disease and better ways to diagnose and treat it. They also hope to learn more about long-term health risks, if any, for people who have had the disease.

Other Names for Kawasaki Disease

• Kawasaki syndrome
• Mucocutaneous lymph node syndrome

What Causes Kawasaki Disease?

The cause of Kawasaki disease isn't known. The body's response to a virus or infection combined with genetic factors may cause the disease. However, no specific virus or infection has been found, and the role of genetics isn't known.

Kawasaki disease can't be passed from one child to another. Your child won't get it from close contact with a child who has the disease. Also, if your child has the disease, he or she can't pass it on to another child.

Who Is At Risk for Kawasaki Disease?

Kawasaki disease affects children of all races and ages and both genders. It occurs most often in children of Asian and Pacific Island descent.

The disease is about 1.5 times more likely to affect boys than girls. Most cases occur in children younger than 5 years, and it's most common in children younger than 3 years. It's very rare in children older than 8 years.

What Are the Signs and Symptoms of Kawasaki Disease?

Major Signs and Symptoms

One of the main symptoms during the early part of Kawasaki disease, called the acute phase, is fever. The fever lasts longer than 5 days. It remains high even after treatment with standard childhood fever medicines.

Other classic signs of the disease are:

• Swollen lymph nodes in the neck
• A rash on the mid-section of the body and in the genital area
• Red, dry, cracked lips and a red, swollen tongue
• Red, swollen palms of the hands and soles of the feet
• Redness of the eyes

Other Signs and Symptoms

During the acute phase, your child also may be irritable and have a sore throat, joint pain, diarrhea, vomiting, and stomach pain.

Within 2 to 3 weeks of the start of the first symptoms, the skin of your child's fingers and toes may peel, sometimes in large sheets.

How Is Kawasaki Disease Diagnosed?

Kawasaki disease is diagnosed based on your child's signs and symptoms and the results from diagnostic tests and procedures.

Specialists Involved

Pediatricians often are the first to suspect a child has Kawasaki disease. Pediatricians are doctors who treat children.

If the disease has affected your child's coronary arteries, a pediatric cardiologist will confirm the diagnosis and give ongoing treatment. Pediatric cardiologists treat children who have heart problems.

Other specialists also may be involved in treating children who have Kawasaki disease.

Signs and Symptoms

The doctor will check your child for the classic signs and symptoms of Kawasaki disease.

The doctor will rule out other diseases that cause similar symptoms. These diseases include Rocky Mountain spotted fever, scarlet fever, and juvenile rheumatoid arthritis.

Generally, your child will be diagnosed with Kawasaki disease if he or she has a fever that lasts longer than 5 days plus four other classic signs or symptoms of the disease.

However, not all children have classic signs and symptoms of Kawasaki disease. Diagnostic tests and procedures can help confirm whether a child has the disease.

Diagnostic Tests and Procedures

Echocardiography

All children suspected of having Kawasaki disease have a test called echocardiography (EK-o-kar-de-OG-ra-fee). This painless test uses sound waves to create images of the heart. These pictures show the coronary arteries.

Doctors use the test when they suspect a child has the disease, but the child has fewer than four of the five classic signs.

Echocardiography also can help show the disease's effects over time, if any, on your child's coronary arteries. Often, the disease's effects on the coronary arteries don't show up until the second or third week after the first symptoms appear. Therefore, this test is done regularly after the diagnosis.

Some children who don't have the classic signs and symptoms of the disease's acute phase may not be diagnosed until 2 to 3 weeks after the onset of the disease. This is when another common sign of Kawasaki disease occurs—peeling of the skin on the fingers and toes.

If your child is diagnosed at this point, he or she will likely need echocardiography right away to see whether the disease has affected the coronary arteries.

Other Diagnostic Tests

Doctors also use other tests to help diagnose Kawasaki disease. These include:

• Blood tests. These tests can show whether the body's blood vessels are inflamed.
• Chest x ray. This test can help show whether Kawasaki disease has affected the heart.
• EKG (electrocardiogram). This simple test detects and records the heart's electrical activity. EKG can show whether Kawasaki disease has affected the heart.

How Is Kawasaki Disease Treated?

Kawasaki disease is mainly treated with medicines. Rarely, medical procedures and surgery may be used for children whose coronary arteries are affected.

The goals of treatment are to:

• Lower fever and reduce inflammation to improve symptoms
• Prevent the disease from affecting the coronary arteries

Initial Treatment

Kawasaki disease can cause serious complications. Therefore, your child will likely be treated in a hospital, at least for the early part of the treatment.

The standard treatment during the disease's acute phase is high-dose aspirin and immune globulin. Immune globulin is a medicine given intravenously (injected into a vein).

Most children who receive these treatments improve greatly within 24 hours. For a small number of children, fever remains. In these cases, a second round of immune globulin may be given.

At the start of treatment, high doses of aspirin are given. As soon as your child's fever goes away, a low dose of aspirin is given. The low dose helps prevent blood clots, which can form in the inflamed small arteries.

Most children treated for Kawasaki disease fully recover from the acute phase and don't need any further treatment. They should, however, follow a healthy diet and adopt healthy lifestyle habits to lower their risk for future heart disease (this is advised for all children, not just those who have the disease).

Children who have had immune globulin should wait 11 months before having the measles and chicken pox vaccines. Immune globulin can prevent those vaccines from working properly.

Long-Term Care and Treatment

If Kawasaki disease has affected your child's coronary arteries, he or she will need ongoing care and treatment. It's best if a pediatric cardiologist provides this care to reduce the risk of severe heart problems. A pediatric cardiologist is a doctor who treats children who have heart problems.

Medicines and Tests

When Kawasaki disease affects the coronary arteries, they may expand and twist. If this happens, your child's doctor may prescribe anticoagulants (like warfarin) to prevent blood clots from forming in the affected coronary arteries.

Anticoagulants usually are stopped after the coronary arteries heal. Healing may occur about 18 months after the acute phase of the disease.

For the small number of children whose coronary arteries don't heal, routine tests are needed. These include:

• Echocardiography. This test uses sound waves to create images of the heart.
• EKG (electrocardiogram). This test detects and records the heart's electrical activity.
• Stress test. This test gives the doctor information about how the heart works during physical activity or stress.

Medical Procedures and Surgery

Rarely, a child may need cardiac catheterization (KATH-e-ter-i-ZA-shun). This procedure is used to diagnose and treat some heart conditions. A long, thin, flexible tube called a catheter is put into a blood vessel in the arm, groin (upper thigh), or neck and threaded to the heart. Through the catheter, doctors can perform diagnostic tests and treatments on the heart.

Very rarely, a child may need to have other procedures, or even surgery, if inflammation narrows his or her coronary arteries and blocks blood flow to the heart. Coronary angioplasty (AN-jee-oh-plas-tee), stent placement, or coronary artery bypass grafting (CABG) may be used.

Coronary angioplasty restores blood flow through a narrowed or blocked coronary artery. A thin tube with a balloon on the end is threaded through a blood vessel in the arm or groin (upper thigh) to the narrowed or blocked coronary artery. The balloon is then inflated to widen the artery and restore blood flow.

A stent may be placed in the coronary artery during angioplasty. Stents are small mesh tubes. They're used to keep narrowed or weakened arteries open. Stents can help improve blood flow and prevent the artery from bursting.

Rarely, a child may need to have CABG. This surgery is used when a coronary artery is severely blocked. During CABG, a healthy artery or vein from another part of the body is connected, or grafted, to the blocked coronary artery. The grafted artery or vein bypasses (that is, it goes around) the blocked part of the coronary artery. This improves blood flow to the heart.

How Can Kawasaki Disease Be Prevented?

Kawasaki disease can't be prevented. However, most children who develop the disease fully recover—usually within weeks of getting signs and symptoms. Further problems are rare.

Living With Kawasaki Disease

Most children who develop Kawasaki disease fully recover—usually within weeks of getting symptoms. Further problems are rare.

However, early treatment is important to reduce the risk of serious problems.

Researchers continue to look for the cause of Kawasaki disease and better ways to diagnose and treat it. They also hope to learn more about long-term health risks, if any, for people who have had the disease.

What To Expect After Treatment

Most children treated for Kawasaki disease fully recover from the acute phase. They don't need further treatment. They should, however, follow a healthy diet and adopt healthy lifestyle habits to reduce the risk for future heart disease (this is advised for all children, not just those who have the disease).

Children treated with immune globulin should wait 11 months before having measles and chicken pox vaccines. Immune globulin can prevent these vaccines from working properly.

Ongoing Health Care Needs

If Kawasaki disease has affected your child's coronary arteries, he or she will need ongoing care and treatment. It's best if a pediatric cardiologist provides this care to reduce the risk of severe heart problems. A pediatric cardiologist is a doctor who treats children who have heart problems.

Support Group

For more information on Kawasaki disease, go to the Kawasaki Disease Foundation Web site. This site provides information about Kawasaki disease, access to volunteers who help families cope with Kawasaki disease, and a link to an online support group for parents and others caring for children with the disease.

Key Points

• Kawasaki disease is a rare childhood disease. In Kawasaki disease, the walls of the blood vessels throughout the body become inflamed. This disease can affect any type of blood vessel in the body, including the arteries, veins, and capillaries.
• The cause of Kawasaki disease isn't known. The body's response to a virus or infection combined with genetic factors may cause the disease. However, no specific virus or infection has been found, and the role of genetics isn't known.
• Kawasaki disease can't be passed from one child to another.
• Kawasaki disease affects children of all races and ages and both genders. It occurs most often in children of Asian and Pacific Island descent. It's more likely to affect males, and most cases occur in children younger than 5 years.
• One of the main symptoms during the early part (acute phase) of Kawasaki disease is fever. The fever lasts longer than 5 days. It remains high even after treatment with standard childhood fever medicines.
• Other classic signs and symptoms are swollen lymph nodes in the neck; a rash on the mid-section and genital area; red, dry, cracked lips and a red, swollen tongue; red, swollen palms of the hands and soles of the feet; and redness of the eyes.
• During the acute phase of Kawasaki disease, your child also may be irritable and have a sore throat, joint pain, diarrhea, vomiting, and stomach pain. Within 2 to 3 weeks of the start of symptoms, the skin on your child's fingers and toes may peel, sometimes in large sheets.
• Kawasaki disease is diagnosed based on your child's signs and symptoms and the results from diagnostic tests and procedures. Generally, your child will be diagnosed with Kawasaki disease if he or she has a fever lasting longer than 5 days and four other classic signs of the disease. Because not all children have classic signs of the disease, diagnostic tests and procedures can help confirm a diagnosis.
• Kawasaki disease is mainly treated with medicines. Rarely, medical procedures and surgery also may be used for children whose coronary arteries are affected.
• Kawasaki disease can't be prevented. However, most children who develop the disease fully recover—usually within weeks of getting signs and symptoms. Further problems are rare.
• If Kawasaki disease has affected your child's coronary arteries, he or she will need ongoing treatment.
• Researchers continue to look for the cause of Kawasaki disease and better ways to diagnose and treat it. They also hope to learn more about long-term health risks, if any, for people who have the disease.

Links to Other Information About Kawasaki Disease

NHLBI Resources

• Vasculitis (Diseases and Conditions Index)

Non-NHLBI Resources

• Kawasaki Disease (MedlinePlus)

Clinical Trials

• Current Research (ClinicalTrials.gov)