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When does gout need treatment? A new set of staging criteria hopes to clarify the answer, and a separate report warns of the risks of unjustified treatment.
A proposed new staging system for gout emphasizes that advanced imagingmay be needed to detect signs of monosodium urate (MSU) crystal deposition to confirm a diagnosis -- with or without signs and symptoms of gout.
The current and widely-used clinical staging system for hyperuricemia (elevated serum urate), gout, flares, and gouty arthritis may describe symptoms adequately, say these authors from New Zealand, but it does not delineate its pathological basis, MSU crystal deposition.
The present system classifies gout into three stages:
The flaw in this system is that imaging with ultrasound (US) or and dual-energy CT (DECT) is needed to spot and analyze MSU formation, crystal deposition in joints, and gouty tophi, which may not produce symptoms.
These authors propose a four-part staging system delineating a disease spectrum:
The proposed system, they argue, would provide a reason to screen of asymptomatic disease, afford a clear focus on gout as a chronic disease of MSU crystal deposition, and establish a rationale for treating asymptomatic disease.
On the latter topic, a report this week in JAMA Internal Medicine highlights the risks of treating asymptomatic hyperuricemia with allopurinol, which it says is contrary to guidelines but nonetheless widespread.
The article recounts seven cases of such unnecessary treatment reported to an Italian monitoring center. One was fatal, a hypersensitivity reaction in a 81-year-old woman with no major health problems or gout history was diagnosed with asymptomatic hyperuricema based on a serum uric acid of 6.6 mg/dL and creatinine 2.31 mg/dL on “routine screening”.
Evidence supports allopurinol for asymptomatic hyperuricemia in three conditions: (1) uric acid above 13 mg/dL in men or 10 mg/dL in women, which has nephrotoxic risks (2) urinary excretion of uric acid >1,100 mg daily, which is associated with an increased risk of uric acid calculi (3) patients about to receive radiation or chemotherapy to prevent uric acid nephropathy from tumor lysis syndrome.