Gout: Pathophysiology and Manifestations

Excess circulating urate levels lead to the crystallization of monosodium urate crystals within joint spaces.

Dietary inclusion of non-purine foods can trigger an acute attack of gout.

The first metatarsophalangeal joint is the most common site affected by gout.

Joint erosions in gout typically develop on the medial corners of a joint.

Juxta-articular osteopenia is a common feature seen in gout.

Gout: Pathophysiology and Manifestations

Mechanism: Excess uric acid in the blood leads to urate crystal formation in joints.
Acute Triggers: Trauma, surgery, dietary changes (purine-rich foods like liver, kidney, game meat, some seafood, alcohol).
Characteristic Lesions (tophi): White, lumpy deposits under the skin; potentially ulcerating, releasing chalky material.
Frequency of Tophi: Less common now due to better treatment.
Typical Joint Involvement: Commonly affects the first metatarsophalangeal joint; but carpometacarpal joints can be severely impacted.
Early Radiographic Sign: Joint effusion (fluid accumulation).
Joint Erosion Features: Erosions typically appear on joint edges. Erosion base shows a sclerotic (hardened) border.
Distinguishing Feature from RA: Lack of juxta-articular osteopenia (bone thinning around the joint), due to acute nature of gout attacks.
Preservation of Joint Space: Relatively late-stage change compared to progression in other inflammatory joint diseases.

Explore the pathophysiology of gout, including the mechanisms behind uric acid accumulation and the resulting crystal formation in joints. This quiz covers triggers, characteristic lesions like tophi, and joint involvement, as well as distinguishing features from rheumatoid arthritis. Test your understanding of gout's manifestations and radiographic signs.