Possible Ambiguity in Interpretation Between Immunoglobulin G4-Related Disease (IgG4-RD) and Sarcoidosis in a Post-COVID-19 Pandemic.

A 36-year-old lady presented with fever, cough, maculopapular rash, painless sialadenitis, episcleritis, and arthralgia of more than 10 months, occurring in episodes since she tested positive for COVID-19 in 2020. Her symptoms were well controlled with corticosteroid and immunosuppressant therapy. Her clinical presentation and findings on bronchoscopy resembled that of sarcoidosis. However, the bronchial biopsy histopathology ruled out sarcoidosis. An increased serum immunoglobulin G4 level and its possible association with COVID-19 raises the question of whether the possibility of immunoglobulin G4-related disease (IgG4-RD) could be entertained.