Supplementary Data and Table for A Detailed Analysis of the Distribution, Morphology, and Histopathology of Complex Purpura in Hospitalized Patients: A Case Series of 68 Patients

We reviewed a case series of 68 inpatients over a four-year period with a dermatologic consultation for purpura and biopsy findings of vasculitis or microvascular occlusion. Key features of complex purpura are non-branching vs. branching (retiform) morphology, dependent vs. acral/generalized distribution, and leukocytoclastic vasculitis (LCV) vs. microvascular occlusion (with emphasis on depth of involvement). Dependent non-branching purpura with only superficial vessels involved by LCV was most often due to IgA vasculitis or cutaneous single-organ small vessel vasculitis. In contrast, deeper involvement by LCV was suggestive of systemic disease (e.g. ANCA-associated vasculitis). Branching purpura was concerning, with greater than 90% sensitivity and specificity for microvascular occlusion and associated high mortality (~50%). The majority of patients who died had acral branching lesions.