Lead-induced chronic gout, unspecified knee, without tophus

This code signifies a chronic inflammatory arthritis caused by elevated lead levels in the body, affecting an unspecified knee joint. The condition is characterized by recurrent attacks of severe pain, swelling, and tenderness, but without the presence of urate crystal deposits (tophi).

Apply this code when documentation confirms a diagnosis of chronic gout directly attributed to lead exposure, specifically impacting a knee joint where the laterality is not specified. This diagnosis requires evidence of both chronic gout and a history or current presence of lead toxicity.

• Ensure documentation clearly links the gout to lead exposure; "lead-associated" or "lead-related" gout supports this.
• Avoid using this code if tophi are present; a different subcategory of M1A would be appropriate.
• Confirm the affected joint is the knee and that laterality (right or left) is not specified in the medical record.