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.