What indicator is a clinical hallmark for diagnosing Kawasaki disease?

Persistent high fever is a key clinical hallmark for diagnosing Kawasaki disease. This condition is characterized by a prolonged fever that typically lasts more than five days and is often resistant to typical antipyretic treatments. The fever usually presents abruptly and is one of the first symptoms to appear, serving as a critical criterion in the diagnosis of Kawasaki disease.

In addition to the persistent high fever, Kawasaki disease may present with other clinical features, but the duration and intensity of the fever are particularly telling. The fever occurs as part of a systemic inflammatory response, which is a hallmark of the disease. Early recognition and diagnosis are crucial because prompt treatment can prevent serious complications, such as coronary artery aneurysms.

Other symptoms like conjunctivitis, dark urine, and joint pain may occur but are not as definitive or critical for diagnosis as the persistent high fever.