Immunofluorescence studies in granuloma eosinophilicum faciale.

Direct immunofluorescence investigations were performed on skin biopsies from five patients with granuloma eosinophilicum faciale (GEF; facial granuloma). An extensive and brilliant granular picture was observed along the basement membrane (BM) of the epidermis and the hair follicles, in the walls of the vessels, in the cellular infiltrates and on the connective tissue fibers. These granules were positively stained by antisera directed against IgG, complement (C3/4) and, although less consistently, against IgA and IgM. IgE was found in one case along the BM, but anti- IgD was negative. Concomitantly heavy fibrillar deposits of fibrin were present in the walls of the vessels and in the cellular infiltrates, together with granular depositions along the BM. The analysis of the complement factors showed that C1q, C4, C3, C3c, C3d and C5 were present in the same pattern as C3/4. These results indicate that GEF can be considered as a chronic form of leukoclastic vasculitis mediated by an Arthus-like mechanism, maintained by an unidentified, persistent antigen or by locally produced Ig aggregates.