Vasculitis in Chronic Urticaria: An Immunopathologic Study

Forty-five patients with chronic urticaria were studied to determine: (1) the histolgic incidence of leukocytoclastic vasculitis and (2) the clinical, laboratory and immunopathologic parameters that characterized this patient group. By histopathologic examination a spectrum of changes were noted as 9 patients showed leukocytoclastic vasculitis, 15a dense perivascular infiltrate of lymphocytes and eosinphils, and 21 only a trate of lymphocytic perivascular infiltrate. Both the vasculitis and the dense infiltrate groups had an increased incidence of circulating immune complexes, as detected by Clq binding and monoclonal rheumatoid factor inhibition radioassays. Direct immonofluorrescence showed blood vessel deposition of immunoglobulins, complement, and/or fibrin in 33% of the vasculitis group, 13% of the dense infiltrate group, and 9% of the sparse infiltrate group. These studies suggest that a meaningful number of patients with chronic urticaria have histologic and immunopathologic findings of vasculitis