A half-century of autopsy results--incidence of pediatric vasculitis syndromes, especially Kawasaki disease.

BACKGROUND The objectives of this study were to clarify the details of pediatric vasculitic diseases on the basis of Japanese autopsy reports and determine whether there were cases of probable Kawasaki disease (KD) even before KD came to be widely recognized as a disease entity. METHODS AND RESULTS Systemic vasculitis autopsy cases aged 15 years or less were selected from the total of 1,335,045 autopsy cases listed in the Annual of Pathological Autopsy Cases in Japan from 1958 through 2008. Those cases were classified into 14 disease groups and then analyzed with regard to various details. There were 380 autopsy cases of vasculitis in children (0.03% of the total autopsy cases). More than half were KD, and other diseases included unclassified vasculitis, polyarteritis nodosa, purpuric vasculitis, Takayasu arteritis, etc. The first recorded case of KD autopsy occurred in 1969. Up until 1976 there was a great difference in the number of autopsies between pediatric vasculitis and KD. However, after 1977 their numbers were in close agreement. The autopsy findings for 24 of 125 child vasculitis autopsies performed before 1976 and diagnosed as non-KD were consistent with KD. CONCLUSIONS Although autopsies of pediatric vasculitis cases are extremely rare, the majority consists of KD. Moreover, it is likely that autopsy cases that were probably KD first appeared in the early 1960s.