Summary of similarities and differences between acute and chronic gout and RA
| Symptoms and diagnostics | Acute gout attack | Chronic tophaceous gout | RA |
|---|---|---|---|
| Clinical pattern | Frequently monoarthritis, large joints such as knee, ankle, and MTP joint | Frequently polyarticular, soft tissue tophi | Symmetrical, mostly small joints (MCP, PIP, MTP, wrists), ulnar deviation, swan neck deformity, buttonhole deformity, rheumatoid foot deformity |
| Symptoms | Redness, swelling, pain, possibly fever | Redness, swelling, pain, possibly fever | Swelling, pain, stiffness |
| Extraarticular manifestation | Subcutaneous edema due to inflammation | Bursa, tendon and soft tissue involvement, extraarticular tophi | Bursa, tendons, vessels, serous membranes, pulmonary involvement, vasculitis |
| Joint ultrasound | Double contour sign, synovitis, positive power doppler signal | Double contour sign, synovitis, positive power doppler signal, effusion tophi, punched-out lesions | Synovitis, positive power doppler erosions, structural damage |
| X-ray | Initially often no bony changes, soft tissue swelling | Tophi, soft tissue tophi, punched-out lesions | Soft tissue swelling, structural changes like erosions, subluxations, deformation, ankyloses |
| Dual energy computed tomography (CT) | Urat crystals are detectable, but in early stages (usually < 6 weeks) the DECT may show false negative results | Urat crystals are detectable if the mass of crystals is high enough | Osteitis in the form of bone marrow edema, synovitis, synovial fluid, structural changes |
| Synovial fluid analysis | Inflammatory synovial fluid (usually increased leukocyte count and a high percentage of granulocytes and rhagocytes) and detection of negative birefringence crystals in polarized light microscopy | Inflammatory synovial fluid with mostly increased cell count and detection of urate crystals in polarized light microscopy | Inflammatory synovial fluid with mostly increased cell count |
| Histology rheumatoid nodules/gouty tophus | Evidence of urate crystals | Evidence of urate crystals | Central fibrinoid necrosis surrounded by histiocytes and epithelioid cells |
