View source for IgG4 related disease

==Background==
*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<ref>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/</ref>
*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

==Evaluation==
*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

==Management==
*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

==Disposition==

==See Also==

==External Links==

==References==
<references/>

[[Category:Rheumatology]]