What is described as rheumatoid arthritis may represent more than one disease. The onset is variable, the course is characterized by remissions and exacerbations, and it is impossible to forecast the future course of events in the individual patient. Diagnosis is difficult in early cases, and an exact prognosis may be difficult even in cases of long duration.
This paper will concern itself solely with rheumatoid arthritis of the peripheral joints. Rheumatoid, or Marie-Strümpell, spondylitis will not be discussed, because it is apparently a different disease and in our opinion should not be classified as rheumatoid arthritis. The reasons for this exclusion are several. The sex distribution is entirely different. In rheumatoid spondylitis 80 per cent of the patients are men, but in rheumatoid arthritis only 23 per cent are men. The agglutination of group A hemolytic streptococci is positive in 50 per cent of patients with rheumatoid arthritis, but