Nasal manifestations of IgG4-related disease: A report of two cases.

IgG4-related disease (IgG4-RD) is a recently recognized clinical disease entity characterized by elevated serum IgG4, tumefaction, tissue infiltration of IgG4-positive plasma cells and fibrosis. IgG4-RD may occur, either synchronously or metachronously, in a variety of organs throughout the body. We describe herein two representative cases of the nasal manifestations of IgG4-RD, characterized by diffuse, crusty, erosive lesions on nasal mucosa. Oral steroid administration was effective in treating these nasal manifestations. We report a decrease in IgG4 positive plasma cell infiltrates in nasal mucosa biopsy specimens after steroid therapy, demonstrating that infiltration of IgG4-positive cells is reversible.