In KD, myocarditis develops even earlier than epicardial coronary arteritis; it peaks by disease day 10 and then disappears gradually after day 20. The myocarditis is distributed unevenly, ranging from the entire heart to the epicardial layer of the base of the heart.

We speculate that endothelial dysfunction in former KD patients is affected by the febrile period of the acute phase, and antiplatelet drugs may improve endothelial function. The increased arterial stiffness of patients caused by post-inflammatory fibrotic changes in the arterial wall indicates that adults with a history of KD have an increased risk of developing atherosclerosis.

In addition to lymphadenopathy with necrosis, KD should be suspected if there is non-purulent inflammation of the LN capsule and/or surrounding connective tissue featuring mainly monocytes/macrophages.