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. [ABSTRACT FROM AUTHOR]