Mumps nephritis

This code signifies renal inflammation, specifically nephritis, that occurs as a complication of a mumps infection. It indicates kidney involvement directly attributable to the mumps virus, which can manifest with symptoms like hematuria, proteinuria, and impaired renal function.

Apply this code when documentation clearly links a patient's nephritis to a confirmed or suspected mumps infection. This typically occurs in patients presenting with acute kidney injury or urinary abnormalities following a recent mumps diagnosis. Supporting documentation should include a mumps diagnosis and evidence of renal involvement.

• Ensure the medical record explicitly states a causal link between mumps and the nephritis.
• Do not use this code for nephritis from other viral causes; specify the correct viral etiology if known.
• Sequence the mumps infection code (B26.-) as the primary diagnosis if the nephritis is a manifestation of the acute mumps.