Articular manifestations of mixed connective tissue disease.

All but one of 28 patients with mixed connective tissue disease (MCTD) who were studied prospectively had arthralgia, and 15 of them had noticed joint swelling. Arthralgia was the first symptom in 14 patients and one of the first two symptoms in 24. Arthralgia was pauciaticular in 4 and polyarticular in 23. Presence of morning stiffness in 15 patients, symmetrical joint swelling in 16, joint deformity in 6, marginal erosions in roentgenograms of the hands of 12, rheumatoid factor in 25, and subcutaneous nodules in 5 caused 24 of the 28 patients with MCTD to fulfill criteria for definite or classic rheumatoid arthritis. All patients, however, also had prominent signs or symptoms of scleroderma, systemic lupus eruthematosus, or polymyositis.