The symptoms of Kawasaki disease are similar to those of an infection, so bacteria or a virus may be responsible. But so far a bacterial or viral cause hasn't been identified.
As Kawasaki disease isn't contagious, it can't be passed from one person to another. This makes it unlikely that it's caused by a virus alone.
Kawasaki disease can affect children of any age. It can be more serious in children under the age of 1.
The children who develop Kawasaki disease may be genetically predisposed to it.
This means the genes they inherit from their parents may make them more likely to get the condition.
One theory is that rather than there being a single gene responsible for Kawasaki disease, it may be the result of many genes that each slightly increase the chances of a child developing the condition.
Kawasaki disease is more common in children from northeast Asia, especially Japan and Korea.
This also suggests there may be a genetic cause.