Kawasaki disease.

Kawasaki disease, a pathologic syndrome known to occur in children, was first described in 1967 as mucocutaneous lymph node syndrome by Kawasaki. The disease occurs chiefly in infants under 4 years of age, presenting with symptoms similar to scarlet fever or Stevens-Johnson syndrome. The changes are found at postmortem and consist of multiple aneurysms and thrombosis, which occur predominantly in the coronary arteries and are responsible for sudden death in most cases. Kawasaki disease is a systemic, acute inflammatory disease entity and in the early stages shows diffuse, necrotizing necrosis. Vasculitis affects primarily the arterioles, venules, and capillaries. Once aneurysmal dilatation has taken place, the wall of the coronary aneurysm becomes thin and the basic structures are destroyed by infiltration of inflammatory cells, which is followed by scar formation within 1 month from the onset of the disease. Coronary arterial lesions are nowadays responsible for the increase of myocardial infarction among the patients. Causes of sudden death include acute ischemia from obstruction or narrowing of the main coronary artery due to thrombosis, thickening of the vascular walls, myocarditis, rupture, and involvement of the conduction system by inflammatory infiltrates, resulting in complete atrioventricular block.