Lead-induced chronic gout, right ankle and foot, with tophus

This code signifies a chronic inflammatory arthritis caused by lead toxicity, specifically affecting the right ankle and foot. The presence of tophi, which are uric acid crystal deposits, indicates a more advanced or severe form of the disease.

This code is appropriate when documentation clearly states a diagnosis of chronic gout directly attributed to lead exposure, localized to the right ankle and foot, and explicitly mentions the presence of tophaceous deposits. Supporting documentation would include laboratory results confirming elevated lead levels and uric acid, imaging studies showing tophi, and physician notes detailing the chronicity and specific joint involvement.

• Ensure documentation specifies "lead-induced" gout; otherwise, a different etiology code for gout should be used.
• Verify the laterality (right) and specific joint involvement (ankle and foot) are clearly documented.
• Confirm the presence of tophi; if absent, a different subcategory of M1A.17 should be selected.