From the Guidelines
Gout is a disorder characterized by an excess body burden of uric acid, leading to the deposition of monosodium urate monohydrate crystals in joints and other tissues, causing acute and chronic arthritis, tophi, and renal manifestations.
Key Features of Gout
- Hyperuricemia: defined as serum urate greater than 6.8 or 7.0 mg/dL, is a key factor in the development of gout 1
- Monosodium urate monohydrate crystals: deposition of these crystals in joints and other tissues leads to the clinical and pathologic features of gout 1
- Acute and chronic arthritis: gout can present as acute, episodic arthritis or chronic arthritis of one or more joints 1
- Tophi: deposits of monosodium urate monohydrate crystals in tissues, detectable by physical exam, imaging, or pathology examination 1
- Renal manifestations: include urolithiasis and chronic interstitial nephropathy, mediated by monosodium urate monohydrate crystal deposition in the renal medulla 1
Diagnosis and Management
- Diagnosis: requires validation against a diagnosis established by identification of monosodium urate crystals, and may involve synovial fluid examination, ultrasound, or MRI 1
- Management: includes pharmacologic and non-pharmacologic approaches, such as urate-lowering therapy, anti-inflammatory drugs, and lifestyle changes 1
- Urate-lowering therapy: aims to reduce serum uric acid levels, allowing monosodium urate crystals to dissolve and preventing acute gout attacks 1
- Anti-inflammatory prophylaxis: may be used to prevent acute gout attacks, especially during the initial phase of urate-lowering therapy 1
From the Research
Definition and Characteristics of Gout
- Gout is a chronic disease caused by monosodium urate (MSU) crystal deposition 2
- It is characterized by abnormally elevated levels of uric acid in the blood 3
- Gout is a form of inflammatory arthritis that can cause acute, extremely painful arthritic flares 4
- It is also known as urate crystal deposition disease 4
Symptoms and Signs of Gout
- The symptoms and signs of gout result from acute and chronic inflammatory responses of the body to urate crystal deposits 4
- Gout typically presents as an acute, self-limiting inflammatory monoarthritis that affects the joints of the lower limb 2
- The metatarsophalangeal (MTP) joint of the great toe (podagra) is the first joint affected in half of all cases 4
- Gout can also cause urinary tract stones and interstitial urate nephropathy in about 20% of patients 4
Diagnosis and Treatment of Gout
- Gout can be diagnosed on clinical grounds in those with typical podagra, or through joint aspiration to demonstrate monosodium urate crystals 5
- The gold standard of diagnosis is identification of characteristic MSU crystals in the synovial fluid using polarized light microscopy 6
- Treatment of gout includes anti-inflammatory agents for acute flares, and urate-lowering therapy (ULT) to reverse chronic urate crystal deposition and prevent recurrent flares 4, 2
- Allopurinol is the first-line urate-lowering therapy, and should be started at a low dose with gradual dose escalation 2