Update on Cutaneous Small Vessel Vasculitis: Terminology, Morphology, Diagnostic Evaluation, and Management

Purpose of the ReviewCutaneous small vessel vasculitis (CSVV) is the clinical presentation of the histologic entity of leukocytoclastic vasculitis (LCV); the vasculitis may be skin-limited, or also affect internal organ systems. Even when skin-limited, it may be a manifestation of a systemic illness. The etiologies and disease associations are broad, ranging from an uncomplicated, self-limited, immunological phenomenon to a harbinger of autoimmune disease, infection, or malignancy. It is a challenging entity for clinicians to provide a thoughtful and comprehensive evaluation for patients presenting with small vessel vasculitis.Recent FindingsA dermatologic addendum to the Chapel Hill Consensus Criteria proposed a logical framework to categorize cutaneous small vessel vasculitis into both skin-limited and systemic variants. Recent publications have demonstrated that branching morphology and systemic symptoms suggest a greater need for systemic work up, while cases presenting with non-branching, venule involvement with scant systemic symptoms may not require extensive evaluation. Moreover, radiological studies have demonstrated limited value.SummaryAs cutaneous small vessel vasculitis is a heterogenous disease entity, an updated understanding of terminology, pathogenesis and lesion morphology will help to inform clinicians when to suspect systemic versus skin-limited disease and guide their evaluation accordingly.