[Which taxonomy for inflammatory diseases in rheumatology? The concept of Psout].

Clinical practice needs the identification of the patient disease. The physician has to rationalize symptoms allowing the recognition of a realistic entity and its classification in a reference nosology. Unlike other practices, the biomedical model uses scientific census methodology, from a tabular perspective to the definition of diseases. Due to its simplification process, it therefore neglects transitional or complex cases. In Rheumatology, this reasoning is challenged by the lack of objectivity and specificity of the items supporting the clinician when he builds the diagnosis, but also by the physiopathological complexity. Sometimes, diseases may be confused or superposed, possibly leading to the description of novel entities. The authors describe herein the difficulties encountered in practical clinical medicine. They show, from a concrete and real personal situation, how it can possibly lead to the justification of a new entity.