The immunofluorescent technique was used to determine the presence of immuno-γ-globulin (IgG) and complement (C′3) in allergic vasculitis (AV) skin lesions. By the use of specific antisera it was possible to demonstrate that IgG and C′3 are present in the areas of fibrinoid necrosis of capillaries and small vessels in the corium. The presence of IgG and complement and the absence of other plasma proteins suggest that an immunologic process is taking place in the pathogenesis of AV. Similarity between these findings and those demonstrated in experimentally-induced Arthus phenomenon has been considered.
STRINGA SG, BIANCHI C, CASALA AM, BIANCHI O. Allergic Vasculitis Gougerot-Ruiter SyndromeImmunofluorescent Study. Arch Dermatol. 1967;95(1):23-27. doi:10.1001/archderm.1967.01600310029005