Urticarial vasculitis.

Thirty seven patients with chronic urticaria were prospectively studied from August 1984 to July 1986. These patients were submitted to regular and immunological laboratory tests. Biopsies were taken from recent urticarial lesions for histologic analysis and also to direct immunofluorescence and immunohistochemistry studies. Vasculitis was found in 27% of the patients. Most of them showed only urticarial lesions except two (20%), that presented residual macula; angioedema occurred in 20% of the urticarial vasculitis (UV) patients; most cases had no systemic manifestations. Serum immunoglobulins and circulant immunocomplexes were increased in both groups. Complement reduction was considered an evidence of vascular aggression, being found in 55% of the UV patients. Direct immunofluorescence studies showed only 10% of positive IgM fluorescence in the vessel walls in the UV group. Immunohistochemical evaluation in the same group revealed mainly slight deposition of immunoglobulins IgG, IgM and IgA in the plasma cells of 80% of the samples and in only 10% there was immunoglobulin deposition in the vessel walls. The authors concluded that conventional histopathology is the best diagnosis method for urticarial vasculitis, direct immunofluorescence and immunoperoxidase being ancillary tools. Therefore, a special group of patients was detected, clinically and therapeutically resembling common urticaria patients, but presenting vasculitis in the histologic exam. This fact leads to the hypothesis that there is a range between common urticaria and urticarial vasculitis with systemic involvement.