Lead-induced chronic gout, right knee, with tophus (tophi)

This code signifies a chronic inflammatory arthritis of the right knee caused by lead toxicity, characterized by the presence of tophi. Tophi are deposits of monosodium urate crystals that form in soft tissues, often around joints, in patients with long-standing hyperuricemia. The lead exposure is the underlying etiology for the chronic gout in this specific anatomical location.

Use this code when documentation clearly indicates chronic gout of the right knee, explicitly linked to lead poisoning, and confirms the presence of tophaceous deposits. This typically applies to patients with a history of lead exposure and clinical findings consistent with chronic gout, including joint pain, swelling, and palpable tophi. Supporting documentation would include laboratory results confirming elevated lead levels and hyperuricemia, imaging studies showing tophi, and physician notes detailing the chronic nature and lead etiology.

• Ensure documentation explicitly links the gout to lead exposure; otherwise, a different etiology code for gout may be more appropriate.
• Verify the laterality (right knee) and the presence of tophi are clearly stated in the medical record.
• Always sequence the lead poisoning code (e.g., T56.0X1A) as a primary diagnosis when it is the underlying cause of the gout.