[Extra-articular manifestations of rheumatoid arthritis]

Rheumatoid arthritis (RA) represents an autoimmune disease affecting mostly joints, in particular small finger and toe joints. In addition RA can show extra-articular manifestations in many organs. Information on the frequency of extra-articular manifestations (EAMs) in RA varies greatly in different publications from 17.8% to 40.9% and EAMs tend to become higher with increasing duration and severity of the disease. The exact etiology and pathogenesis are still unclear but vasculitic alterations together with deposition of immune complexes can often be found histopathologically in affected organs. It must also be taken into consideration that EAMs can also be a result of the pharmaceutical therapy. The organ findings can vary greatly which is also reflected in the multitude of clinical symptoms. Possible target organs are the blood vessels, kidneys, central nervous system, cardiovascular system, the lungs, eyes, skin, nails as well as blood and the hemopoetic system. The prognosis for RA becomes progressively worse in the presence of EAMs. Regular and continuous control investigations are necessary in order to be able to diagnose EAMs early and to begin therapy. Therapy includes the administration of non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying antirheumatic drugs (DMARDs) and especially in advanced stages cyclophosphamide or biologicals. Therapy is still very empirical due to the lack of appropriate studies.