Mumps arthritis

This code represents inflammation of one or more joints (arthritis) specifically caused by the mumps virus. It is a rare complication of mumps infection, typically presenting with acute joint pain and swelling following the onset of parotitis.

Apply this code when documentation clearly indicates a diagnosis of arthritis directly attributed to a mumps infection. This typically occurs in patients with a confirmed mumps diagnosis who subsequently develop arthritic symptoms.

• Ensure documentation specifies the causal link between mumps and the arthritis; "mumps with arthritis" is insufficient without explicit causation.
• Sequence this code as the primary diagnosis if the arthritis is the reason for the encounter, otherwise, sequence it after the code for mumps (B26.x).
• Do not confuse with other forms of viral arthritis or post-infectious arthritis where mumps is not the causative agent.