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

This code signifies a chronic inflammatory arthritis of the left knee caused by lead toxicity, characterized by the presence of tophi. Tophi are deposits of monosodium urate crystals that form visible lumps under the skin or in other tissues.

Apply this code when documentation confirms a diagnosis of chronic gout directly attributed to lead exposure, specifically affecting the left knee and presenting with tophaceous deposits. Supporting documentation should include laboratory findings indicating elevated lead levels and uric acid, as well as imaging or physical exam findings confirming tophi in the left knee.

• Ensure documentation clearly links lead exposure as the etiology of the gout.
• Verify the specific joint involved (left knee) and the presence of tophi.
• Do not use for acute gout or gout without documented lead etiology.