What are the diagnostic criteria for Gout (Gouty Arthritis)?

From the Guidelines

The diagnosis of gout should be based on the 2015 ACR/EULAR classification criteria, which incorporate clinical, laboratory, and imaging findings, with a score of 8 or more considered diagnostic for gout. The identification of monosodium urate (MSU) crystals in synovial fluid or tophus aspirates using polarized light microscopy is the most definitive diagnostic method 1. Clinical criteria, such as the presence of acute monoarthritis, typically affecting the first metatarsophalangeal joint (podagra), with rapid onset of severe pain, swelling, and erythema, are also important. Some key points to consider in the diagnosis of gout include:

• The presence of tophi, which has a high predictive value for gout, with an odds ratio of 7.29 [95% CI, 2.42 to 21.99] 1
• Resolution of pain by 2 weeks, which has an odds ratio of 3.58 [CI, 1.85 to 6.95] 1
• The double contour sign on ultrasonography, which has an odds ratio of 7.23 [CI, 3.47 to 15.04] 1
• Imaging studies, such as dual-energy CT, which can specifically identify MSU deposits, and MRI, which can help assess the extent of inflammation The 2015 ACR/EULAR classification criteria have a sensitivity of 92% and specificity of 89% (including clinical and imaging domains) or 85% and 78% (excluding imaging) 1. Key considerations in using the 2015 ACR/EULAR classification criteria include:
• A score of 8 or more is considered diagnostic for gout
• The criteria incorporate clinical, laboratory, and imaging findings
• The presence of MSU crystals in synovial fluid is considered diagnostic for gout, but if this criterion is not met, a hierarchical set of 7 criteria is applied.

From the FDA Drug Label

Patients meeting American College of Rheumatology criteria for gout

• The diagnostic criteria for gout is based on the American College of Rheumatology criteria.
• The FDA drug label does not provide the specific criteria, only that patients must meet these criteria to be diagnosed with gout 2.

From the Research

Diagnostic Criteria for Gout

The diagnostic criteria for gout include:

• Clinical criteria from the American College of Rheumatology 3
• Identification of monosodium urate crystals in synovial fluid of the affected joint 3, 4
• Presence of tophi on physical examination 5
• Response of arthritis to colchicine 5
• Identification of the double-contour sign in ultrasound (US) 5
• Detection of urate deposits by dual-energy computed tomography (DECT) 5

Clinical Presentation

Gout typically presents with:

• Sudden and severe pain in a joint, most commonly the first metatarsophalangeal joint 4, 6
• Swelling, pain, or tenderness in a peripheral joint or bursa 6
• Development of a tophus 6

Laboratory and Imaging Findings

Laboratory and imaging findings that can aid in the diagnosis of gout include:

• Synovial fluid analysis 3, 4
• Ultrasound (US) findings, such as the double-contour sign 5
• Dual-energy computed tomography (DECT) findings, such as detection of urate deposits 5
• Serum uric acid levels, although asymptomatic hyperuricemia is common and usually does not progress to clinical gout 7