Kawasaki disease is a rare condition in children that involves inflammation of the blood vessels.

Kawasaki disease occurs most frequently in Japan, where the disease was first discovered. In the United States, Kawasaki disease is the leading cause of acquired heart disease in children. It affects more than 4,000 children each year. Eighty percent of patients are younger than age 5.

Kawasaki disease is a poorly understood illness. The cause has not been determined. It may be an autoimmune disorder. The disorder affects the mucus membranes, lymph nodes, walls of the blood vessels, and the heart.

Kawasaki disease can cause inflammation of blood vessels in the coronary arteries, which can lead to aneurysms. An aneurysm can lead to a heart attack, even in young children, although this is rare.

Kawasaki disease often begins with a high and persistent fever greater than 102°F, often as high as 104°F. A persistent fever lasting at least 5 days is considered a classic sign. The fever may last for up to 2 weeks and does not usually go away with normal doses of acetaminophen (Tylenol) or ibuprofen.

Other symptoms often include:

• Extremely bloodshot or red eyes (without pus or drainage)
• Bright red, chapped, or cracked lips
• Red mucous membranes in the mouth
• Strawberry tongue, white coating on the tongue, or prominent red bumps on the back of the tongue
• Red palms of the hands and the soles of the feet
• Swollen hands and feet
• Skin rashes on the middle of the body, NOT blister-like
• Peeling skin in the genital area, hands, and feet (especially around the nails, palms, and soles)
• Swollen lymph nodes (frequently only one lymph node is swollen), particularly in the neck area
• Joint pain and swelling, frequently one both sides of the body

There are no tests that specifically diagnose Kawasaki disease. The diagnosis is usually made based on the patient having most of the classic symptoms.

However, some children may have a fever lasting more than 5 days, but few of the other classic symptoms of the disease. Therefore, all children with fever lasting more than 5 days should be evaluated, with Kawasaki disease considered as a possibility. Early treatment is essential for those who do have the disease.

The following tests may be performed:

• Chest x-ray
• Complete blood count
• C-reactive protein (CRP)
• Echocardiogram
• Electrocardiogram
• ESR
• Serum albumin
• Serum transaminase
• Urinalysis - may show pus in the urine or protein in the urine

Procedures such as ECG and echocardiography may reveal signs of myocarditis, pericarditis, arthritis, aseptic meningitis, and inflammation of the coronary arteries.

Children with Kawasaki disease are admitted to the hospital. Treatment must be started as soon as the diagnosis is made to prevent damage to the coronary arteries and heart.

Intravenous gamma globulin is the standard treatment. It is given in high doses. The child's condition usually greatly improves within 24 hours of treatment with IV gamma globulin.

High-dose aspirin is often given along with IV gamma globulin.

Despite aspirin and IVIG treatment, 10 - 15% of children still develop problems in their coronary arteries. Some research has suggested that adding steroids to the usual treatment routine may improve a child's outcome, but more research is needed.

With early recognition and treatment, full recovery can be expected. However, 2% of patients die from complications of coronary blood vessel inflammation. Patients who have had Kawasaki disease should have an echocardiogram every 1 - 2 years to screen for heart problems.

Complications involving the heart, including vessel inflammation and aneurysm, can cause a heart attack at a young age or later in life.

Call your health care provider if symptoms of Kawasaki disease develop. A persistent high fever that does not come down with acetaminophen or ibuprofen and lasts more than 24 hours should be evaluated by a health care provider.

There are no known measures that will prevent this disorder.

Burns, JC. Revisiting steroids in the primary treatment of acute Kawasaki disease. J Pediatrics. 2006; 149: 291-292.

Freeman AF, Shulman ST. Kawasaki disease: summary of the American Heart Association guidelines. Am Fam Physician. 2006 Oct 1;74(7):1141-8.