Undoubtedly an essential thing in a correct diagnosis is a knowledge of the fact that arthritis deformans often occurs as an acute polyarthritis, with a sudden onset, and that unless care is taken the condition is especially apt to be regarded as acute articular rheumatism. Here, as is usually the case, knowledge of the possibilities is an essential to correct diagnosis. It may be taken for granted that the advanced stages with the marked characteristic deformity are not likely to be mistaken, but of what value is diagnosis then when the possibility of preventing these later changes is the hoped-for thing? Practically, the study of the diagnosis will be confined to the early stages. The more acute forms have to be diagnosed, especially from acute articular rheumatism, acute gout, acute polyarthritis from other causes (for example, septic conditions, etc.), and gonorrheal arthritis.
Acute Articular Rheumatism.
—There are several features that