Signs and Symptoms of Chronic Gout
Chronic gout is characterized by the deposition of monosodium urate (MSU) crystals in joints, cartilage, tendons, bursae, bone, and soft tissue, leading to persistent symptoms including tophi formation, chronic arthritis, and joint damage.
Key Clinical Features
Tophi
- Solid MSU crystal aggregates that form in various tissues 1, 2
- Common locations:
- Joints (especially first metatarsophalangeal joint)
- Helix of the ear
- Olecranon bursa
- Interphalangeal joints
- Tendons
- Bursae
- Soft tissues 3
- Appear as nodular, firm deposits that may be visible under the skin
- May cause joint deformity and limitation of movement
- Development correlates with both degree and duration of hyperuricemia 3
Joint Manifestations
- Chronic inflammatory polyarthritis (unlike the monoarticular presentation of acute gout)
- Joint damage and destruction from prolonged crystal deposition
- Asymmetrical joint swelling (LR 4.13) 1
- Subcortical cysts without erosion on radiography (LR 6.39) 1
- Limitation of joint movement
- Chronic joint pain between acute flares (intercritical periods become shorter and eventually disappear) 3
Radiographic Findings
- Grade progression from periarticular soft tissue swelling to:
- Tophaceous deposits (eccentric/asymmetrical nodular masses with/without calcifications)
- Cartilaginous and osseous destruction with erosions
- Intraosseous calcific deposits and subperiosteal bone apposition 1
- "Punched-out" erosions with overhanging edges
- Joint space narrowing
- Asymmetrical swelling 1
Systemic Manifestations
Renal Complications
- Urinary tract stones (occur in approximately 20% of gout patients) 3
- Interstitial urate nephropathy
- Chronic kidney disease 2, 4
Associated Comorbidities
- Metabolic syndrome components:
- Cardiovascular disease:
- Coronary artery disease
- Heart failure
- Stroke 3
Disease Progression
Natural History
- Evolution from acute intermittent attacks to chronic persistent symptoms 1
- Progression occurs in untreated hyperuricemia 3
- Intercritical periods (pain-free intervals between flares) become progressively shorter
- Eventually, persistent symptoms may develop without clear flares 1, 3
Factors Affecting Progression
- Degree and duration of hyperuricemia
- Inadequate treatment of hyperuricemia
- Presence of comorbidities (especially renal impairment)
- Continued exposure to dietary and lifestyle risk factors 2, 4
Diagnostic Considerations
While definitive diagnosis requires identification of MSU crystals in synovial fluid or tophus aspirates 1, 2, chronic gout has distinctive clinical features:
- History of prior acute gout attacks (typically monoarticular)
- Presence of visible tophi
- Characteristic radiographic changes
- Persistent hyperuricemia (though serum uric acid may be normal during acute flares) 2
Clinical Pitfalls and Caveats
- Chronic tophaceous gout can mimic other conditions such as rheumatoid arthritis, osteoarthritis, or even tumors like synovial sarcoma 5
- Serum uric acid levels alone cannot confirm or exclude gout diagnosis, as levels may be normal in up to 14-63% of patients during acute attacks 2
- Tophi may be mistaken for rheumatoid nodules or other soft tissue masses
- Gout and septic arthritis can coexist; when septic arthritis is suspected, Gram stain and culture should be performed even if MSU crystals are identified 2
- Large tophi are unusual but can occur in untreated chronic gout, involving multiple joints including hands, feet, elbows, and knees 6
Proper management of chronic gout requires urate-lowering therapy with a target serum urate level of <6 mg/dL as a minimum, or <5 mg/dL for faster tophi resolution 2. Early diagnosis and treatment are essential to prevent the progression to chronic tophaceous gout and its associated complications.