Omalizumab-based therapy in normocomplementemic urticarial vasculitis: a retrospective case series of 18 patients.

BACKGROUND: Urticarial Vasculitis (UV) is a rare immune-complex-mediated vasculitis characterized by urticarial lesions lasting ≥24 hours and small-vessel inflammation. Management is challenging, and evidence for omalizumab, an anti-IgE monoclonal antibody, remains limited. OBJECTIVES: To evaluate clinical and laboratory outcomes and safety of omalizumab-based therapy in patients with clinicopathologically diagnosed normocomplementemic UV. METHODS: This retrospective study included 18 patients with clinicopathologically diagnosed normocomplementemic UV treated with omalizumab. Demographics, disease duration, comorbidities, and laboratory parameters (C-Reactive Protein [CRP], Erythrocyte Sedimentation Rate [ESR], total Immunoglobulin E [IgE]) and Urticaria Activity Score over 7 days (UAS7) were assessed before and after treatment. RESULTS: Eighteen patients (14 females, 4 males) with a mean age of 47.3 ± 16.8 years were included. Mean disease duration was 15.8 ± 10.8 months, and mean omalizumab treatment duration was 14.8 ± 12.0 months. Mean UAS7 decreased significantly from 25.3 ± 7.7 to 1.2 ± 3.4 (p < 0.001). CRP also decreased significantly (10.7 ± 17.2 to 3.6 ± 3.3 mg/L; p = 0.002), while the reduction in ESR was not significant (18.2 ± 26.5 to 10.9 ± 7.8 mm/h; p = 0.124). Total IgE increased after treatment (451.6 ± 1075.5 to 496.4 ± 621.2 IU/mL; p = 0.010). Complete remission occurred in 17 patients (94%). No treatment-related adverse events were observed. STUDY LIMITATIONS AND CONCLUSIONS: Limitations include retrospective design, small sample size, lack of a control group, and concomitant therapies. Omalizumab was associated with marked clinical improvement and favorable safety in normocomplementemic UV, supporting a potential role for IgE-mediated mechanisms.