From the Guidelines
Diagnosing a gout flare requires a combination of clinical judgment and laboratory testing, with synovial fluid analysis being the gold standard for definitive diagnosis, as recommended by the American College of Physicians 1 and the European League Against Rheumatism 1. When diagnosing a gout flare, it is essential to look for characteristic symptoms such as sudden onset of intense joint pain, typically affecting the big toe (podagra), though ankles, knees, and other joints can be involved. The affected joint will appear red, swollen, warm, and extremely tender to touch, with pain that may be so severe that even the weight of a bedsheet is unbearable.
Key Diagnostic Considerations
- Joint fluid analysis is the gold standard for diagnosing gout, as it allows for the direct identification of monosodium urate (MSU) crystals 1.
- Blood tests showing elevated uric acid levels (typically above 6.8 mg/dL) can support the diagnosis but are not conclusive alone, as levels can be normal during an acute attack 1.
- Imaging studies like ultrasound or dual-energy CT can detect crystal deposits and joint damage in chronic cases, and are recommended when clinical diagnosis is uncertain and crystal identification is not possible 1.
Recommendations for Diagnosis
- Synovial fluid analysis should be performed in every person with suspected gout, as it allows for a definitive diagnosis 1.
- A clinical diagnosis of gout is supported by suggestive features such as monoarticular involvement of a foot or ankle joint, previous similar acute arthritis episodes, rapid onset of severe pain and swelling, erythema, male gender, and associated cardiovascular diseases and hyperuricaemia 1.
- The diagnosis of gout should not be made on the presence of hyperuricaemia alone, and risk factors for chronic hyperuricaemia should be searched for in every person with gout 1.
From the Research
Diagnosing a Gout Flare
Diagnosing a gout flare typically involves a combination of clinical, laboratory, and radiologic findings. The following are some key points to consider:
- Gout is characterized by the deposition of monosodium urate crystals in joints and other tissues, leading to an acute inflammatory response 2, 3, 4, 5, 6.
- The diagnosis of gout can be made using several validated clinical prediction rules, and arthrocentesis should be performed when suspicion for an underlying septic joint is present 3, 4.
- Demonstrating the presence of monosodium urate (MSU) crystals in the joint fluid or tophus is the gold standard for the diagnosis of gout, but many physicians do not perform synovial fluid analysis 4.
- Clinical presentations of gout typically include sudden and severe pain in a peripheral joint or bursa, including the development of a tophus 3, 4.
- Laboratory and radiologic studies, such as uric acid levels and joint X-rays, can also be helpful in making the diagnosis of gout 4, 6.
- Risk factors for gout include male sex, obesity, hypertension, alcohol intake, and a diet rich in meat and seafood 3.
Clinical Findings
Some common clinical findings in patients with gout include:
- Swelling, pain, or tenderness in a peripheral joint or bursa 3
- Development of a tophus 3, 4
- Acute intense inflammation of the involved joint 6
- Chronic tophaceous gout and chronic gouty arthropathy 6
Laboratory and Radiologic Findings
Some common laboratory and radiologic findings in patients with gout include: