Systemic Vasculitides: Classification Updates, Pathogenesis, and Contemporary Management

This chapter offers a comprehensive review of the primary systemic vasculitides, from ANCA-associated vasculitis and giant cell arteritis to Takayasu arteritis and IgA vasculitis, incorporating the latest updates to classification and disease activity frameworks. Immunopathogenic mechanisms including neutrophil–endothelial interactions, CD4+ T-cell driven granuloma formation, and aberrant complement activation are reviewed alongside evidence-based treatment algorithms featuring rituximab, avacopan, and tocilizumab.