Chronic tophaceous gouty arthritis mimicking rheumatoid arthritis

Objectives: To analyze the factors which differentiate chronic tophaceous a rthritis from rheumatoid arthritis, Methods: We describe two cases of chronic gouty arthritis masquerading as r heumatoid arthritis. The characteristic features of each of these two condi tions and the diagnostic approach are discussed in light of relevant litera ture. Results: The correct diagnosis was reached by the combination of accurate h istory taking (family history of gout, alcoholism, previous diuretic therap y and renal stones), guiding clinical features (subcutaneous tophaceous dep osits) and specific radiological (assymetrical erosions with sclerotic marg ins and overlying edges) and laboratory findings (hyperuricemia and hyperur icosuria). It was confirmed by the identification of monosodium urate (MSU) crystals in the synovial and subcutaneous tissues. Conclusions: Gout and rheumatoid arthritis rarely coexist. Chronic gouty ar thritis may mimic rheumatoid arthritis, and vice-versa. Clinical suspicion supplemented by characteristic laboratory, radiological and histologic find ings help at reaching an accurate diagnosis. Semin Arthritis Rheum 29:56-63 . Copyright (C) 1999 by W.B. Saunders Company.