Palmar bands in rheumatoid arthritis and other chronic conditions of the upper limb.

Palmar prolapse of the flexor tendons as a result of attenuation of the A1 and A2 pulleys occurs in rheumatoid arthritis and other conditions in which the joints of the fingers are chronically flexed. The flexor tendons may be palpable and sometimes visible as longitudinal bands crossing the palm. This can lead to confusion with the palmar bands of Dupuytren's disease. These bands are illustrated in a small series of patients and a serious complication of a misdiagnosis of Dupuytren's disease is presented. The pathogenesis of these palmar bands in rheumatoid arthritis is discussed.