Drug-induced gout, unspecified knee

This code signifies an inflammatory arthritis of the knee caused by a medication, where the specific drug responsible is not identified. It is characterized by the deposition of uric acid crystals in the joint, leading to pain, swelling, and redness. This condition is distinct from primary gout or gout secondary to other medical conditions.

Use this code when documentation clearly states "drug-induced gout" affecting the knee, and the specific drug causing the reaction is not specified. This diagnosis is typically supported by a history of medication use preceding gout symptoms, elevated serum uric acid levels, and exclusion of other causes of gout.

• Always attempt to identify and code the specific drug causing the adverse effect using an additional external cause code (T36-T50 with a 5th or 6th character indicating adverse effect).
• Distinguish from M10.0- (idiopathic gout) or M10.1- (lead-induced gout) which have different etiologies.
• If the laterality of the knee (right or left) is documented, use the more specific codes M10.261 or M10.262.