Kawasaki syndrome is a fever-based illness that primarily affects children younger than five years of age. It is characterized by a fever, rash, swelling of the hands and feet, irritation of the mouth lips and throat, and redness in the eyes. The cause of Kawasaki syndrome is unknown. It doesn’t appear to be hereditary or contagious. Because the illness frequently occurs in outbreaks within a population, an infectious agent (such as a virus) is the likely cause.