Medicine Matters rheumatology

2018 EULAR updated evidence-based recommendations for the diagnosis of gout

Final set of recommendations

EULAR (2006) evidence based recomendations for gout (Diagnosis)

1. Search for crystals in synovial fluid or tophus aspirates is recommended in every person with suspected gout, because demonstration of MSU crystals allows a definitive diagnosis of gout.

3. Demonstration of MSU crystals in synovial fluid or tophus aspirates permits a definitive diagnosis of gout

2. Gout should be considered in the diagnosis of any acute arthritis in an adult.

When synovial fluid analysis is not feasible, a clinical diagnosis of gout is supported by the following suggestive features: monoarticular involvement of a foot (especially the first MTP) or ankle joint; previous similar acute arthritis episodes; rapid onset of severe pain and swelling (at its worst in <24 hours); erythema; male gender and associated cardiovascular diseases and hyperuricaemia. These features are highly suggestive but not specific for gout.

1. In acute attacks the rapid development of severe pain, swelling, and tenderness that reaches its maximum within just 6–12 hours, especially with overlying erythema, is highly suggestive of crystal inflammation though not specific for gout

2. For typical presentations of gout (such as recurrent podagra with hyperuricaemia) a clinical diagnosis alone is reasonably accurate but not definitive without crystal confirmation

3. It is strongly recommended that synovial fluid aspiration and examination for crystals is undertaken in any patient with undiagnosed inflammatory arthritis.

4. A routine search for MSU crystals is recommended in all synovial fluid samples obtained from undiagnosed inflamed joints

4. The diagnosis of gout should not be made on the presence of hyperuricaemia alone.

7. While being the most important risk factor for gout, serum uric acid levels do not confirm or exclude gout as many people with hyperuricaemia do not develop gout, and during acute attacks serum levels may be normal

5. When a clinical diagnosis of gout is uncertain and crystal identification is not possible, patients should be investigated by imaging to search for MSU crystal deposition and features of any alternative diagnosis.

(Not commented on either for ultrasound or DECT: Knowledge not developed for gout in 2004, when the task force first met)

6. Plain radiographs are indicated to search for imaging evidence of MSU crystal deposition but have limited value for the diagnosis of gout flare.

Ultrasound scanning can be more helpful in establishing a diagnosis in patients with suspected gout flare or chronic gouty arthritis by detection of tophi not evident on clinical examination, or a double contour sign at cartilage surfaces, which is highly specific for urate deposits in joints.

9. Although radiographs may be useful for differential diagnosis and may show typical features in chronic gout, they are not useful in confirming the diagnosis of early or acute gout.

7. Risk factors for chronic hyperuricaemia should be searched for in every person with gout, specifically: chronic kidney disease; overweight, medications (including diuretics, low-dose aspirin, cyclosporine, tacrolimus); consumption of excess alcohol (particularly beer and spirits), non-diet sodas, meat and shellfish.

10 (1). Risk factors for gout (…) should be assessed (…)

8. Systematic assessment for the presence of associated comorbidities in people with gout is recommended, including obesity, renal impairment, hypertension, ischaemic heart disease, heart failure, diabetes and dyslipidaemia.

10 (2). (…) and associated co-morbidity should be assessed, including features of the metabolic syndrome (obesity, hyperglycaemia, hyperlipidaemia, hypertension)

5. Identification of MSU crystals from asymptomatic joints may allow definite diagnosis in intercritical periods

Not commented on specifically

6. Gout and sepsis may coexist, so when septic arthritis is suspected Gram stain and culture of synovial fluid should still be performed even if MSU crystals are identified

Not commented on specifically

8. Renal uric acid excretion should be determined in selected gout patients, especially those with a family history of young onset gout, onset of gout under age 25, or with renal calculi