Reiter's disease, right knee

This code signifies a diagnosis of Reiter's disease, also known as reactive arthritis, specifically affecting the right knee. Reiter's disease is an inflammatory arthropathy that typically develops after an infection, often genitourinary or gastrointestinal, and presents with a characteristic triad of arthritis, urethritis, and conjunctivitis, though not all components may be present.

Apply this code when documentation clearly indicates a diagnosis of Reiter's disease with inflammatory involvement of the right knee joint. This code is appropriate when the physician explicitly states "Reiter's disease, right knee" or "reactive arthritis, right knee" in the diagnostic statement.

• Ensure documentation specifies "Reiter's disease" or "reactive arthritis" and laterality (right knee).
• Do not confuse with other forms of inflammatory arthritis without a clear indication of reactive arthritis.
• Code any associated infections (e.g., Chlamydia, Salmonella) as primary diagnoses if they are the underlying cause and still active, following sequencing guidelines.