[Early arthritis: action desired - treatment required].

Rheumatoid Arthritis (RA) is the most prevalent inflammatory joint disease in adults and shows a destructive course in most cases. The outcome of the disease - functional decline and invalidity - necessitates an early therapy. Recent studies demonstrate that the initiation of the treatment with a disease modifying antirheumatic drug (DMARD) treatment within the first three months after the onset of symptoms is crucial for sustained improvement of prognosis as well as therapeutic success and outcome. In the early stage of the disease, the criteria for the classification of Rheumatoid Arthritis (RA) are frequently not met. Up to over 50% of the patients show an arthritis, which cannot be classified and therefore is seen as undifferentiated arthritis (UA). Early therapeutic intervention appears to prevent the chronification of the disease; thus an early and appropriate disease modifying therapy is mandatory. Age, gender, involvement of the hands, positive rheumatoid factor, as well as the detection of anti cyclic-citrullinated peptide antibodies (anti-CCP Ab) are predictors of the development of RA. Beside conventional X-rays, there are other imaging methods such as magnetic resonance tomography imaging, Power-Doppler or contrast medium enhanced sonography, which may enable the detection not only of synovitis but also of erosive lesions at very early stages. Those patients suffering from UA carry a high risk for the development of a destructive arthritis as seen in RA, and therefore should be treated with an adequate DMARD. In these cases methotrexate is still the drug of first choice.