IgG4 related disease


  • IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory illness of unknown etiology
  • It's a multi organ disease that most commonly affects the pancreas, kidneys, retroperitoneum, salivary glands and orbits

Clinical Features

  • No specific symptoms as it is dependent on which organs are affected
  • Autoimmune pancreatitis is the most common presentation of IgG4-RD and can be mistaken for malignancy[1]
  • Patients do not typically experience generalized symptoms such as fevers or night sweats

Differential Diagnosis

  • Pancreatic cancer
  • Sjogren's syndrome
  • Primary sclerosing cholangitis
  • Retroperitoneal fibrosis
  • Castleman disease


  • Typically, diagnosis not made in the ED

Outpatient Workup

  • Tissue biopsy with IgG stain is required for diagnosis
  • Serum IgG4 levels are usually elevated and helpful for diagnosis and also helpful for serial monitoring
  • C3 and C4 complement levels may be decreased
  • Total serum IgG levels may also be elevated


  • Prednisone at higher doses is the current standard treatment
  • Further immunosuppression may be warranted based on response to prednisone
  • Consultation with a rheumatologist is usually necessary


See Also

External Links


  1. Nambiar S, Oliver TI. IgG4 Related Disease. [Updated 2022 May 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499825/