Immunoglobulin G4 sinusitis in association with aspirin-exacerbated respiratory disease

Background: Immunoglobulin G4 (IgG4) related disease is a systemic inflammatory disease characterized by tumor-like tissue infiltration with IgG4 positive (IgG4) plasma cells. Aspirin-exacerbated respiratory disease (AERD) is defined as asthma, chronic rhinosinusitis with nasal polyposis, and hypersensitivity to cyclooxygenase-1 inhibitors. Objective: We described a case of a non-smoking 61-year-old male with prior NSAID sensitivity who presented with a 1-year history of left eye proptosis associated with chronic nasal symptoms, ultimately identified as concurrent AERD and IgG4 sinusitis. Methods: The patient was evaluated in the clinic and diagnosed by using clinical, radiographic, and surgical biopsy findings. Results: Although initial concern was greatest for malignancy, a biopsy specimen confirmed the presence of a dense lymphoplasmacytic infiltrate and storiform fibrosis, associated with increased IgG4 plasma cells. Therefore, IgG4-related disease (RD) was identified in this patient with AERD. Conclusion: Shared type II inflammation may be responsible for the coexistence of IgG4-RD and AERD as observed in our patient. Health care workers must be cognizant of the simultaneous presentation of both IgG4-RD and AERD.