"It was traditionally described as occurring post-rheumatic fever. It is also seen in association with systemic lupus erythematosus (SLE) and other rheumatic and non-rheumatic conditions including psoriatic arthritis, inflammatory bowel disease and malignancy 5. It is thought to be related to ligamentous laxity 7."
"Typically affects the metacarpophalangeal joints but can also affect the proximal interphalangeal joints of the hands, wrists and knees 2."