ABSTRACT
Large gaps in the understanding of nosology, etiology, and pathogenesis confound the study of vasculitis. This lack of information, in turn, complicates attempts at classification. Primary vasculitides may be classified according to their clinical manifestations, the size of blood vessels involved, the histology of vascular damage, or the presumed disease pathogenesis. This chapter uses a working scheme for classifying pediatric vasculitides, attempting to include current knowledge of disease pathogenesis but leaving open the possibility of reclassification as new data emerge (Table 24).
