IgG4 related pleural disease: Recurrent pleural effusion after COVID ‐19 vaccination

IgG4‐related disease is characterized by a systemic fibroinflammatory process associated with substantial infiltration by plasma cells with IgG4 in the organs. Our patient presented with pleural effusion, and was diagnosed with IgG4‐related lung disease (IgG4‐RLD) after he received two doses of the Pfizer COVID‐19 vaccine. The patient developed dyspnea and hypoxia 2 weeks after receiving the second dose of the Pfizer COVID‐19 vaccine. CT scan revealed left pleural effusion which was drained. However, the effusion recurred requiring thoracoscopic drainage, placement of an indwelling catheter, and decortication with biopsy. IgG4 serum level was 268 mg/dl and pathology revealed pleural fibrosis, lymphoplasmacytic infiltrates, and increased IgG4‐positive plasma cells with no malignant cells leading to a diagnosis of IgG4‐RLD. Although COVID vaccine‐related IgG4‐RLD is a novel finding, having a high degree of suspicion following vaccination is always important for early diagnosis and effective treatment.