ABSTRACT
Seronegative arthritides are a heterogeneous group of diseases that includes rheumatoid arthritis with negative rheumatoid factor. Between 1980 and 1984 we studied 38 patients with seronegative arthritis. Thirty of these patients were reassessed in 1994 after 9 or 20 years of evolution. Seventeen patients had a diagnosis of seronegative rheumatoid arthritis; this diagnosis was maintained in 12, changed to seropositive rheumatoid arthritis in 3, to psoriatic arthritis in 1 and connective tissue disease in 1. Thirteen patients had a diagnosis of undifferentiated arthritis; in 1994 the diagnosis was maintained in 3, 7 patients were diagnosed as having a sppondyloarthropathy, 2 as having a reactive arthritis and 1 as having a connective tissue disease. In 1994, nine patients fulfilled the 1991 criteria for spondyloarthritis and 6 of these did so on admission. Six of 12 patients with seronegative rheumatoid arthritis had an active disease or used antiinflammatory drugs and 64 percent had erosions on hand X ray examination. These figures are in contrast with the enigm evolution classically attributed to this disease and agree with recent reports. The usefulness of classification criteria for rheumatoid arthritis and spondyloarthritis in the initial assessment of patients with seronegative arthritis is emphasized