De Ritis Ratio Is a Potential Independent Predictor of Recurrence of Single-Organ Cutaneous Small Vessel Vasculitis

Background/objectives: According to the Chapel Hill Consensus Conference nomenclature, single-organ cutaneous small vessel vasculitis (SOCV) is defined histopathologically by immune complex-mediated vasculitis of the dermal capillaries/venules without systemic involvement. There is a lack of investigations studying predictors of SOCV outcomes. This multicenter retrospective study aimed to assess whether baseline serum liver scores could predict SOCV recurrence. Methods: Data from 204 inpatients with histopathologically confirmed idiopathic SOCV treated between 2000 and 2022 were analyzed. All patients had baseline blood tests for platelets and liver parameters; those with systemic diseases were excluded. The study evaluated the AST to Platelet Ratio Index (APRI), Fibrosis-4 (FIB-4) index, and De Ritis ratio (DRR). Results: Recurrence was observed in 17.6% of patients. Univariable analysis identified hospital stay length, DRR, cutaneous extent, and cardiovascular comorbidities as predictors, but logistic regression confirmed only cutaneous extent and DRR as independent predictors of disease recurrence. Conclusions: A higher DRR (cut-off > 1.13) may indicate necrosis from reduced blood flow, making it a potential predictor of SOCV recurrence.