13. Heberden and Bouchard nodes
Two distinct nodes form in patients with gout. Heberden nodes are found in the distal interphalangeal joints, and Bouchard nodes affect the proximal interphalangeal joints. They both form in the fingers but at different levels and are signs of degenerative joint disease, especially osteoarthritis. These nodes are basically bony enlargement, known clinically as exostosis. There is a genetic predisposition to developing these nodes, which explains why some patients have them and others do not. It apparently happens because the cartilage between the joints breaks down, and bone spurs develop between bone ends. The joint undergoes erosion and inflammation, causing a rupture in the capsule and synovial liquid leakage.