A case of emphysematous pyelonephritis in a patient with rheumatoid arthritis taking corticosteroid and low-dose methotrexate.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that is characterized by chronic synovial inflammation. Patients with RA have increased risk of infection; this is related to RA itself or the adverse effects of medication. In this report, we describe a case of emphysematous pyelonephritis in a patient with RA associated with AA amyloidosis and steroid-induced diabetes mellitus who was taking corticosteroid and low-dose methotrexate.