INTRODUCTION

Kawasaki disease (KD, also called mucocutaneous lymph node syndrome) is one of the most common vasculitides of childhood [1]. It is typically a self-limited condition, with fever and other acute inflammatory manifestations lasting for an average of 12 days if not treated. Complications such as coronary artery aneurysm, cardiomyopathy with depressed myocardial contractility and heart failure, myocardial infarction, arrhythmias, and peripheral arterial occlusion may develop, which may cause significant morbidity and mortality. (See "Cardiovascular sequelae of Kawasaki disease".)

The frequency of aneurysm development and mortality have been dramatically decreased as a result of intravenous immune globulin therapy; early diagnosis is critical to achieve the optimal treatment result. The epidemiology and etiology of Kawasaki disease will be reviewed here. The clinical features, diagnosis, treatment, and cardiac sequelae are presented separately. (See "Clinical manifestations and diagnosis of Kawasaki disease" and "Initial treatment and prognosis of Kawasaki disease" and "Cardiovascular sequelae of Kawasaki disease".)

EPIDEMIOLOGY

Geographical variation — The incidence of KD is greatest in children who live in East Asia or are of Asian ancestry living in other parts of the world [2-4]. The following studies illustrate the geographical and ethnic variation in the incidence of KD:

• Japan — KD is a reportable disease in Japan and more than 100,000 cases of KD have been registered there since its initial description by Tomisaku Kawasaki in 1967 [5,6]. The incidence among children younger than five years of age is approximately 100 per 100,000 per year, but it may be increasing [7]. In a retrospective review of 84,829 cases reported over 14 years between 1987 and 2000, the incidence of KD in children younger than five years of age increased from 74 per 100,000 in 1987 to 140 per 100,000 in 2000 [8]. In 2007 and 2008, the annual incidence rates in children aged zero to four years were 215 and 219 per 100,000 , respectively [9]. The bimodal seasonality of KD, with rates highest in the winter month of January, and in the summer months of June and July, remains a characteristic of KD incidence in Japan.
• Taiwan and China — Data from the Taiwan National Health Insurance Database indicate that the incidence of KD among children younger than five years was 69 per 100,000 per year between 2003 and 2006 [10]. A hospital-based survey of KD in all 45 hospitals in Beijing reported an increase in the incidence in children younger than five years of age from 41 per 100,000 in 2000 to 51 per 100,000 in 2004 [11].
• United States — Studies of hospital discharge records by the United States Centers for Disease Control (CDC) estimated an overall annual incidence of 17 to 27 per 100,000 children younger than five years in the United States [2,12]. Annual incidence was highest among Asians and Pacific Islanders (33 per 100,000), intermediate among non-Hispanic African Americans (17 per 100,000) and Hispanics (11 per 100,000), and lowest among Caucasians (9 per 100,000) [2]. In contrast to Japan, surveillance in the United States is passive and many cases may be missed.

The overall incidence was 22 per 100,000 children less than five years of age in San Diego County during a six-year period from 1998 to 2003 [3]. The rates based upon ethnicity were 15.3, 20.2 and 45.9 per 100,000 children less than five years of age for whites, white Hispanics, and Asian/Pacific Islanders, respectively.