Urticaria. An immunofluorescence and histopathology study

Abstract

Fourteen randomly chosen patients with "garden variety" urticaria were studied for the presence of vasculitis and immunoglobulins and complement. Results of direct immunofluorescence (DIF) of the involved skin were negative, although two patients had immunoglobulins and complement demonstrable in the cytoplasm of the epidermal cells. Results of DIF of uninvolved skin were also predominantly negative. Findings from serum samples tested by indirect immunofluorescence (IIF) were negative, except for one positive in low titer (1:10, the basement membrane zone). Serum C3 and C4 levels were normal in five patients, both levels were low in two, and the C4 level was low in one patient. No skin-reactive immunoglobulins were found in these three patients by DIF or IIF. The ESR was measured and found to be elevated in four patients. Results of immunofluorescence proved negative in these cases. Of the 12 patients studied by hematoxylineosin staining to determine histology, none exhibited vasculitis. We believe that vasculitis with antigen-antibody reactions is not the rule in "garden variety" urticaria.

Pathogenetic Studies in Chronic Urticaria

“…In contrast with others [5,6,15,25], we did not find lowered serum levels of com plement components. Consistent with the results of Berrens et al [26], the mean com plement values were within normal ranges.…”

“…In our opinion, the diagnosis 'vasculitis' should be based on infiltration of inflammatory cells, leukocytoclasis and fibrinoid deposits in and around the vessel walls. Using these criteria, we found no vasculitis in CU, which is in agreement with Small et al [8] and Synkowski et al [15]. Moreover, direct IF failed to show deposits of immunoglobulin, com plement or fibrin.…”

Diagnostic utility of direct immunofluorescence test panels for cutaneous vasculitis: A scoping review

“…43 Nowadays, this subset would likely be reclassified as UV. Studies of DIF findings in urticaria [43][44][45] and UV (both HUV [an entity closely linked to systemic lupus erythematosus] and normocomplementemic UV [NUV] have been undertaken). [46][47][48][49] In studies of DIF findings in HUV in comparison to NUV, HUV appears to have a substantially higher rate of basement membrane zone (BMZ) granular deposition (range: 60%- 96%) [47][48][49] compared to NUV (up to 33%).…”

Complement Activation in Inflammatory Skin Diseases

“…In parallel with early studies, the presence of complement, especially C5a, had a role in augmenting IgG-dependent histamine release from basophils ( 101 ). Although the immune reaction in urticaria is regarded as a type 1 and type 2 hypersensitivity reaction, also local complement deposition can be found in about one-third of chronic urticarial lesions without signs of systemic activation, suggesting a type 3 hypersensitivity reaction as well ( 102 – 105 ).…”