Artritis reumatoide (I)

Rheumatoid arthritis (RA) is the most common chronic inflammatory arthritis and affects around 0.5-1% of the general population. The aetiology of RA is unknown and its pathogenesis is only partially known. In recent years several risk factors for the development of the RA have been studied and identified. It is known that genetic and environmental factors have an influence in the origin of the disease. Symmetrical joint involvement is characteristic and affects the peripheral joints, while the involvement of axial and central joints is less common. Extra articular features and comorbidity may occur and determine the prognosis. Early recognition and treatment are important, however, in patients with early disease it is often difficult to distinguish from other forms of inflammatory polyarthritis; in such cases laboratory and image testing are important.