Can some cases of 'possible' spondyloarthropathy be classified as 'definite' or 'undifferentiated' spondyloarthropathy?: Value of criteria for spondyloarthropathies

Objectives. When evaluating patients for spondyloarthropathy, clinicians use the 'possible spondyloarthropathy' category to indicate that they are unsure about the diagnosis. We sought to determine whether Amor's criteria or the European Spondyloarthropathy Study Group (ESSG) criteria could lift this uncertainty. Patients and methods. During a Spanish study designed to validate criteria for spondyloarthropathies, 102 patients were classified in the 'possible spondyloarthropathy' category. We divided these patients into subgroups based on whether or not they met criteria for spondyloarthropathy. We compared baseline characteristics (N = 102) and five-year outcomes (N = 52) in these subgroups. Results. The following features were significantly more common in the subgroups of patients who met Amor's criteria for spondyloarthropathy: oligoarthritis, heel pain, uveitis, balanitis, family history of spondyloarthropathy, and presence of the HLA B27 antigen. No differences were found for age at symptom onset, disease duration, buttock pain, gender, dactylitis, diarrhea, or psoriasis. Of the 52 patients followed up for five years, 17 met Amor's criteria at baseline and 13 were subsequently found to have definite spondyloarthropathy, which was undifferentiated in six cases. There were only three cases of spondyloarthropathy among the 28 patients who did not meet Amor's criteria at baseline. Of the 28 patients who met ESSG criteria at baseline, 13 had spondyloarthropathy versus three of the 17 patients who did not meet ESSG criteria at baseline. Conclusion. Amor's criteria or the ESSG criteria allow early classification of most patients with 'possible spondyloarthropathy' and early identification of undifferentiated spondyloarthropathy corresponding to minimal-symptom or incipient disease, in this study, Amor's criteria performed better than the ESSG criteria. (C) 2000 Editions scientifiques et medicales Elsevier SAS.