Drug-induced chronic gout, left ankle and foot, with tophus

This code signifies chronic gout affecting the left ankle and foot, specifically caused by a medication, and characterized by the presence of tophi. Tophi are deposits of uric acid crystals that form under the skin or in joints, indicating long-standing and poorly controlled hyperuricemia. The drug-induced nature differentiates it from other forms of gout.

Apply this code when documentation clearly states chronic gout in the left ankle and foot, explicitly attributes its cause to a drug, and confirms the presence of tophaceous deposits. This typically occurs in patients with a history of medication use known to precipitate gout, such as diuretics or certain immunosuppressants, who present with chronic joint pain, swelling, and palpable tophi in the specified anatomical location.

• Ensure the medical record explicitly links the gout to a specific drug and documents the presence of tophi.
• Do not use this code for acute drug-induced gout; a different subcategory exists for acute presentations.
• Always sequence the drug-induced gout code first, followed by an additional code from Chapter 20 (External Causes of Morbidity) to identify the specific drug.