Idiopathic chronic gout, unspecified hand, with tophus

This code signifies a long-standing, primary form of gout affecting an unspecified hand, characterized by the presence of tophi. Tophi are deposits of uric acid crystals that form visible lumps under the skin, often around joints, indicating advanced or poorly controlled gout.

Use this code when documentation clearly indicates chronic gout of unknown origin affecting the hand, and specifically mentions the presence of tophaceous deposits. This diagnosis is typically supported by physical examination findings, imaging studies, and a history of recurrent gout flares.

• Ensure documentation specifies "idiopathic" or "primary" chronic gout to differentiate from secondary forms.
• Confirm the presence of tophi; if tophi are not documented, a different code for chronic gout without tophi would be appropriate.
• If the specific hand (right or left) is known, a more specific code (M1A.0411 or M1A.0421) should be used instead.