[Rheumatoid polyarthritis. Misleading aspects and its doubles].

The diagnosis of rheumatoid arthritis is easy for typical forms, but is difficult in certain cases. This is especially true at the onset of the disease. In fact, 10 to 15 p. cent of rheumatoid arthritis cases present onsets which are more or less deceptive, either in their mode, or localization. Until now, no valid assistance could be expected from the pathology, serology or even immunogenetics and molecular biology. In forms seen in their active phase, there are a number of diseases, of various causes, which may simulate rheumatoid polyarthritis. It is absolutely necessary to recognize them in order not to embark on an erroneous therapeutic approach.