Case Report of <scp>IgG4</scp> ‐Related Autoimmune Pancreatitis

ABSTRACT This case presents a clear diagnosis with a complete chain of clinical evidence. Long‐term follow‐up revealed that, despite excellent disease control, the condition relapsed more than 6 months after discontinuation of glucocorticoids, with a tendency toward further progression. This outcome sharply contrasts with recommendations in several authoritative guidelines, which state that long‐term discontinuation of glucocorticoids may be appropriate for such patients. A 44‐year‐old Han Chinese man was first diagnosed with IgG4‐related autoimmune pancreatitis (AIP) at our institution in 2022. Prior to the diagnosis, he experienced recurrent episodes over a 3‐year period due to treatment as ordinary acute pancreatitis. After the diagnosis was confirmed, standardized glucocorticoid therapy led to complete resolution of symptoms, normalization of serum IgG4 levels, and remarkable recovery of pancreatic morphology, including disappearance of the perivascular fibrotic cuff. After 2 years and 8 months of glucocorticoid use, the patient discontinued the medication on his own. His condition deteriorated rapidly, and he subsequently experienced disease relapse characterized by pancreatic atrophy with pancreatic duct dilatation. This case highlights the potential risk of disease relapse and progressive pancreatic morphological changes following prolonged discontinuation of glucocorticoid therapy in IgG4‐related autoimmune pancreatitis. This observation underscores the need for careful long‐term follow‐up after glucocorticoid discontinuation in patients with IgG4‐related autoimmune pancreatitis. However, further studies are required to clarify optimal treatment duration and long‐term outcomes.