Kawasaki Disease

Abstract

Kawasaki disease (KD) is an acute systemic inflammatory illness that occurs predominately in children <5 years of age. The reported incidence varies widely depending on the ethnicity of the population and the method of case ascertainment. Recent reports would suggest the annual incidence is ≈20 to 25 per 100 000 children <5 years of age in North America, with the highest reported incidence of 188 being in Japan, where the disease was first described in 1967.1 The illness is self-limited and of unknown cause, but is complicated by a systemic vasculitis with a predilection for small- to medium-sized arteries, particularly the coronary arteries. The majority of patients will have either transient coronary artery dilation or no coronary artery luminal changes as noted on echocardiography. Long-term prognosis for these patients is considered to be excellent. Coronary artery aneurysms occur in 25% of patients, but the prevalence is reduced to ≈4% for patients treated with intravenous immunoglobulin infusion within 10 days of illness onset. Aneurysms are associated with an intense inflammatory cell infiltrate, destruction of the internal elastic lamina, and smooth muscle cell death. Coronary artery involvement is usually maximal within 6 to 8 weeks after the acute episode. Regression of aneurysms can occur primarily through myointimal proliferation, although the arterial structure and function remains abnormal,2 and there is an important ongoing risk of stenoses and occlusions.3 Long-term cardiology assessment and management is required, and some of these patients may require revascularization procedures or, rarely, cardiac transplantation. KD has become the most prevalent acquired cardiac disease in children in developed countries. Article see p 60 Although coronary artery complications are the predominant cause of morbidity and mortality, other cardiovascular abnormalities can occur. Valvulitis is a less prevalent complication, and there have been case reports of important long-term aortic and …