[Confronted with mono-arthritis: which tests?].

A monoarthritis may correspond to a localized inflammatory process or to the onset of rheumatoid disease that may later on spread over few or several of the other joints. In this article the different diagnostic and therapeutic steps to approach monoarthritis are presented. One of the first investigations consists in an analysis of the synovial fluid. It should take place before any therapeutic step is initiated and may allow to diagnose a microcrystalline or a septic arthritis. By means of a literature review monoarthritis is described as a disease, whose cause remains often undisclosed inspite of intensive investigations, whose further course, however, is often favorable.