RESUMO
Diagnosis of arthritis with recent onset is still an unresolved problem. In 1984 we started an outpatient clinic for patients with early arthritis of less than one year duration. Of a total of 226 patients seen 149 (66%) had definite (n = 76; 34%) or probable (n = 73; 32%) inflammatory rheumatic disease, and 77 (34%) had degenerative or extraarticular rheumatic disease. Thirtynine patients were classified as undifferentiated arthritis. This undefined arthritis was often monoarticular (12%) and oligoarticuler (44%). One patient met 5 ARA-criteria for rheumatoid arthritis, 14 (36%) met 3-4 ARA-criteria and 25 (64%) only 1-2 ARA-criteria. ESR was elevated in only 23 (59%) patients, rheumatoid factor was positive in 7 (19%) patients and HLA-B27 was positive in 9 (23%) patients. Seventeen (44%) patients had a history of recent infections preceding the beginning of joint symptoms. Thus undifferentiated arthritis represents a heterogeneous group of diseases. Despite diagnostic progresses in recent years a high proportion of early arthritis cannot be diagnosed definitely.