Untreated tophaceous gout

Abstract

Gout is associated with hyperuricemia and characterized by inflammatory arthritis induced by monosodium urate crystal deposition in synovial fluid and other tissues. Tophi can occur in soft and osseous tissue, ligaments, and different organs, either in presence or absence of gouty arthritis. If left untreated, hyperuricemic patients (serum urate level = 6.8 mg/dL or 400 mol/L) can evolve from intermittent arthritis to polyarticular tophaceous gout with symptoms between attacks. Lowering serum urate levels with xanthine oxidase inhibitors or uricosuric agents prevents acute flares and tophi development. Synovial fluid crystals slowly dissolve and can disappear after normalization of serum urate levels. Uricosuric agents are, generally, ineffective in patients with renal impairment. The recommended target serum uric acid concentration is <6 mg/dL (357 mol/L). Although controversial, recommendations have been made to achieve a target serum urate level <5 mg/dL (297 mmol/L) in severe chronic gout patients, as this concentration may be associated with greater depletion of synovial fluid crystals and a reduction in tophus size. Therapy is usually continued indefinitely. Several urate-lowering agents are currently under clinical investigation. These include uricase agents and inhibitors of renal urate transporter proteins. Interventions which enhance patient education and treatment adherence are considered important in improving gout management.