Clinical Manifestations of Gouty Arthritis
Gouty arthritis typically presents as self-limited attacks of synovitis characterized by rapid development of severe joint pain, swelling, and tenderness that reaches its maximum within just 6-12 hours, especially with overlying erythema, most classically in the first metatarsophalangeal joint. 1, 2
Acute Gout Attack Characteristics
- Acute gout characteristically presents as self-limited attacks of synovitis (also called "gout flares") that can be debilitating and are associated with decreased work productivity and quality of life 1, 3
- Pain severity varies from mild (≤4 on a 0-10 scale) to moderate (5-6) to severe (≥7) 1
- Duration of attacks can be categorized as early (<12 hours), well established (12-36 hours), or late (>36 hours) 1
- Rapid onset of symptoms with maximum intensity typically reached within 6-12 hours 2
- Overlying erythema is common, giving the affected joint a red, hot, and swollen appearance 2
Joint Involvement Patterns
- Most commonly affects the first metatarsophalangeal joint (podagra), which is considered the hallmark presentation 2
- Can involve one or multiple small joints, one or two large joints (ankle, knee, wrist, elbow, hip, or shoulder), or present as polyarticular involvement 1
- Polyarticular gout is defined as either acute arthritis involving 3 separate large joints, or acute arthritis of 4 or more joints with arthritis involving more than 1 "region" of joints 1
- Joint "regions" include forefoot, midfoot, ankle/hindfoot, knee, hip, fingers, wrist, elbow, shoulder, and others 1
- Acute bursal inflammation due to gout (e.g., in the prepatellar or olecranon bursa) may also occur 1
Clinical Stages of Gout
- Intermittent acute attacks with asymptomatic periods between flares (intercritical periods) 1, 3
- Progression to more chronic symptoms may occur as a result of either joint damage or chronic synovitis 1
- In some patients, monosodium urate (MSU) crystals may aggregate in intra- or extra-articular regions to form tophi 1
- Chronic tophaceous gouty arthropathy can develop with persistent inflammation, joint deformity, and disability 1
Diagnostic Features
- Presence of MSU crystals in synovial fluid aspirated from the affected joint is the gold standard for diagnosing gout 1, 2
- Clinical signs and symptoms combined with laboratory findings can help make a provisional diagnosis when joint aspiration is not feasible 1
- Recently developed algorithms including clinical, laboratory, and imaging criteria demonstrate good sensitivity (up to 88%) and specificity (up to 96%) for diagnosing gout 1
- Imaging modalities such as dual-energy computed tomography (DECT) and ultrasonography can aid in diagnosis, with DECT showing sensitivities of 85-100% and specificities of 83-92% 1
- Ultrasonography may reveal the "double contour sign" with pooled sensitivity of 74% and specificity of 88% 1
Pathophysiology
- Gout results from deposition of monosodium urate crystals in joints and tissues due to chronic hyperuricemia 3
- MSU crystals directly stimulate the inflammasome in leukocytes, causing an acute inflammatory attack 1
- During the initial phase of urate-lowering therapy, there is often an early increase in acute gout attacks due to remodeling of articular urate crystal deposits 1
Common Pitfalls in Diagnosis
- Relying solely on serum uric acid levels without clinical correlation can lead to misdiagnosis, as some patients with acute gout may have normal levels during an attack 3
- Failing to consider gout in joints other than the first metatarsophalangeal joint, as it can affect various joints including unusual locations 4
- Not performing synovial fluid analysis when feasible, which remains the gold standard for definitive diagnosis 2
- Overlooking the importance of treating comorbidities that contribute to hyperuricemia 3
By understanding these clinical manifestations, healthcare providers can more accurately diagnose gouty arthritis and initiate appropriate treatment to alleviate symptoms and prevent long-term complications.