Treatment
Children with Kawasaki disease should be hospitalized and cared for by a physician who has experience with this disease. In an academic medical center, care is often shared between pediatric cardiology, pediatric rheumatology, and pediatric infectious disease specialists (although no specific infectious agent has yet been identified). To prevent damage to coronary arteries, treatment should be started immediately following the diagnosis.Intravenous immunoglobulin  (IVIG) is the standard treatment for Kawasaki disease and is administered in high doses with marked improvement usually noted within 24 hours. If the fever does not respond, an additional dose may be considered. In rare cases, a third dose may be given. IVIG is most useful within the first seven days of fever onset, to prevent coronary artery aneurysm. IVIG given within the first 10 days of the disease reduces the risk of damage to the coronary arteries in children, without serious adverse effects.Salicylate therapy, particularly aspirin, remains an important part of the treatment (though questioned by some) but salicylates alone are not as effective as IVIG. There is limited evidence to indicate whether children should continue to receive salicylate as part of their treatment. Aspirin therapy is started at high doses until the fever subsides, and then is continued at a low dose when the patient returns home, usually for two months to prevent blood clots from forming. Except for Kawasaki disease and a few other indications, aspirin is otherwise normally not recommended for children due to its association with Reye syndrome.
However, a Cochrane review published in 2017 (updated in 2022) found that, in children, the use of corticosteroids in the acute phase of KD was associated with improved coronary artery abnormalities, shorter hospital stays, a decreased duration of clinical symptoms, and reduced inflammatory marker levels. Patient populations based in Asia, people with higher risk scores, and those receiving longer steroid treatment may have greater benefit from steroid use. Prognosis
With early treatment, rapid recovery from the acute symptoms can be expected, and the risk of coronary artery aneurysms is greatly reduced. Untreated, the acute symptoms of Kawasaki disease are self-limited (i.e. the patient will recover eventually), but the risk of coronary artery involvement is much greater, even many years later. Many cases of myocardial infarction in young adults have now been attributed to Kawasaki disease that went undiagnosed during childhood. Overall, about 2% of patients die from complications of coronary vasculitis.Laboratory evidence of increased inflammation combined with demographic features (male sex, age less than six months or greater than eight years) and incomplete response to IVIG therapy create a profile of a high-risk patient with Kawasaki disease. The likelihood that an aneurysm will resolve appears to be determined in large measure by its initial size, in which the smaller aneurysms have a greater likelihood of regression. Other factors are positively associated with the regression of aneurysms, including being younger than a year old at the onset of Kawasaki disease, fusiform rather than saccular aneurysm morphology, and an aneurysm location in a distal coronary segment.