Vasculitis in Chronic Urticaria: An Immunopathologic Study

Abstract

Forty-five patients with chronic urticaria were studied to determine: (1) the histologic 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, 15 a dense perivascular infiltrate of lymphocytes and eosinophils, and 21 only a sparse 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 immunofluorescence 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.

Microscopic Morphology of Different Types of Urticaria

“…39 Infiltrates of neutrophils, eosinophils or eosinophil products, activated macrophages, and T-helper lymphocytes have been described before in lesions of chronic and cholinergic urticaria and in DPU, with the last involving primarily the lower dermis. [2][3][4]10,17,18,39 In about half of our patients with chronic urticaria and also those of Monroe et al, 5 mononuclear cells were predominant. It remains to be clarified whether this is due to an increased duration of these lesions before biopsy or to specific pathological features.…”

Pathogenetic Studies in Chronic Urticaria

“…Moreover, direct IF failed to show deposits of immunoglobulin, com plement or fibrin. These results are in con trast with those of Monroe et al [1] and Rus sel Jones et al [23]. This discrepancy is probably due to a differnce in patient selec tion; in contrast with our series, many of the patients of these authors had associated symptoms pointing to urticarial vasculitis.…”

“…In patients with CU, histological and im munopathological features of necrotizing (leukocytoclastic) vasculitis [1][2][3][4] have been observed as well as hypocomplementemia [5][6][7] and evidence of circulating immune complexes [1,4,5,8]. These findings suggest a relationship between CU and urticarial vasculitis.…”

“…The condition varies con siderably, from a mild illness, e.g. urticaria [1], to a severe disease, e.g. systemic lupus erythematosus (SLE) [13,14].…”

“…It is, therefore, important to know how many pa tients with CU show immunological and histopathological features of urticarial vas culitis. In the literature there are conflicting reports; some authors mentioned that vas culitis is a common finding in CU [1,3,4], others, however, did not [8,15,16]. Atten tion has also been paid to fibrinolysis in ur ticaria [17]; activated complement factors may trigger fibrin formation and fibrinoly sis and products of the latter system may conversely trigger the complement system [18].…”