[Crystal-induced arthritis--old but important].

Gout is the most common inflammatory arthropathy for men. Asymptomatic hyperuricemia, which should lead to diet, but not to medication, is much more common still. Increased uric acid levels mostly result from diminished renal excretion, which is more commonly familiar than secondary (renal failure, diuretics). With the first episode of often typical (red, hot, exquisitely painful first MTP joint) acute arthritis or with urate nephrolithiasis, increased uric acid turns pathological. Attacks are treated with NSAIDs or corticosteroids. More common attacks, chronic gout, or urate nephropathy are definite indications for long-term (at least 5 years) therapy with allopurinol or febuxostat. Additional anti-inflammatory medication will be necessary during the first months. Calcium pyrophosphate deposition arthropathy, the second common crystal-induced arthritis, is diagnosed by synovial fluid analysis or for chondrocalcinosis. Treatment for attacks resembles therapy of acute gout; causal therapy is possible in case of secondary forms (e.g. hypothyroidism. hyperparathyroidism, hemochromatosis).