Kawasaki syndrome is a potentially fatal inflammatory disease that affects several organ systems in the body, including the heart, circulatory system, mucous membranes, skin, and immune system. Infants and children are at highest risk (80% are children under 4), but adults have also been diagnosed with the condition. Its cause is unknown.

Nearly twice as common among men, the disease affects Asians more often than either blacks or whites, but it doesn't seem to be found in any one particular part of the world. Although the disease usually occurs in single cases, it sometimes affects several members of the same family and occasionally occurs in small epidemics.

The specific cause of Kawasaki syndrome is unknown, although the disease resembles infections in many ways. Kawasaki syndrome may represent an allergic reaction or another unusual response to certain infections. Some researchers think that the syndrome may be caused by the...