RESUMO
An increasing number of cases have reported that coronavirus disease 2019 (COVID-19) can lead to immune system dysregulation and induce autoimmune diseases, but the mechanism is unclear. We treated a patient who presented with an unknown fever after infection with the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2023. After excluding the possibility of infection, malignancy, and other connective tissue diseases, we considered the diagnosis of IgG4-related disease in consideration of the patient's pathology and clinical findings. In this article, we summarize our diagnostic experience and summarize the case reports of IgG4-related diseases associated with SARS-CoV-2 infections since the COVID-19 pandemic.