IgG4-Related Disease is an immunomediated condition that is characterized by the presence of inflammatory lesions associated with fibrosis and lymphoplasmacytic infiltration rich in positive IgG4 tissue plasmocytes, forming a spectrum of fibroproliferative diseases. The pathogenesis of IgG4-RD is still poorly understood and the treatment is empirical. We report the case of a 50-year-old man with yellow eyelid lesions associated with local edema, previously diagnosed as an allergic process, until biopsy with immunohistochemical study and serum IgG4 dosage revealed the hypothesis […]