title: Renal disease masquerading as pyrexia of unknown origin.
abstract: Pyrexia of unknown origin is a challenging clinical problem. Infections, malignancies, and connective tissue diseases form the major etiologies for this condition. We report a case of a 57-year-old diabetic male who presented with fever of unknown origin for several months. The course of investigations led to a kidney biopsy which clinched the cause of his fever as well as the underlying diagnosis. The light microscopy findings of expansile storiform fibrosis with a dense inflammatory infiltrate suggested the diagnosis which was confirmed by positive staining of Immunoglobulin G4, the dense lympho-plasmacytic infiltrate and elevated serum IgG4 concentrations. A course of steroids followed by mycophenolate mofetil as maintenance immunosuppression rendered the patient afebrile with improvement of renal function.
authors: Department of Nephrology, Bombay Hospital, New Marine Lines, Mumbai, Maharashtra, India.
authors: D
authors: D
authors: Korivi
authors: V
authors: V
authors: Billa
authors: K
authors: K
authors: Patel
authors: C
authors: C
authors: Madiwale
keywords: Autoimmune pancreatitis; corticosteroids; immunoglobulin G4 related disease; interstitial fibrosis; tubulointerstitial nephritis
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