Arthritis of Acute Rheumatic Fever
The arthritis of ARF usually involves larger joints, particularly the knees (75%) and ankles (50%), and less commonly elbows/wrists/hips (15%). The shoulder, spine, and smaller joints of the hands and feet are less commonly involved. Typically, several joints are involved at a time in a migratory polyarthritis pattern, along with an acute febrile illness. Patients are usually symptomatic for 1 to 2 (rarely longer than 4) weeks. ARF does not cause erosions or permanent joint damage, with the rare exception of Jaccoud deformity, which can occur following multiple recurrences of ARF. Synovial fluid is sterile and inflammatory.
