IgG4-Related Autoimmune Pancreatitis in Patients with Prior Occupational Exposure: A Case Report and Review of Risks Concerning Blue-Collared Workers

Autoimmune pancreatitis (AIP), a manifestation of IgG4-related disease (IgG4-RD), is a rare, often misdiagnosed condition that can closely mimic pancreatic cancer, particularly in its clinical and radiographic presentation. We report the case of a 76-year-old retired plumber who presented with painless jaundice and was initially suspected to have pancreatic cancer based on imaging findings. Subsequent endoscopic evaluation, biopsy, and markedly elevated serum IgG4 levels led to a diagnosis of type 1 AIP. Treatment with corticosteroids resulted in rapid clinical improvement and reduction in IgG4 levels, confirming the diagnosis. This case highlights the diagnostic challenges of AIP, especially among blue-collar workers with limited access to subspecialty care and potential exposure to immune-disrupting substances such as asbestos, chemical fumes, and mineral dusts. A targeted literature review supports an emerging association between occupational exposure and IgG4-RD. Recognition of these risk factors is critical to avoid unnecessary oncologic interventions and ensure timely, appropriate treatment. Clinicians should maintain a high index of suspicion for AIP in patients with pancreatic masses and relevant occupational histories. Early diagnosis using criteria such as HISORt and prompt initiation of steroid therapy can significantly reduce morbidity. Further research is needed to refine diagnostic tools and better understand occupational risk factors contributing to IgG4-RD in diverse patient populations.