Kawasaki disease occurs most frequently in Japan, where the disease was first discovered, but it occurs in all ethnicities. In the United States, where Kawasaki disease is the leading cause of acquired heart disease in children, over 4,000 children develop it each year. 80% of patients are younger than 5 years of age. Kawasaki disease is a poorly understood illness. The cause has not been determined. It may be an autoimmune disorder precipitated by unknown outside factors. The disorder affects the mucus membranes, lymph nodes, walls of the blood vessels, and the heart. The heart's involvement and complications are, by far, the most important aspect of the disease. Kawasaki disease can cause inflammation of blood vessels in the coronary arteries, which can lead to aneurysms. (An aneurysm is a weakened area of blood vessel that balloons out.) Such aneurysms can lead to heart attack, even in young children (rarely).
| 
