Caracterización de pacientes con artritis indiferenciada y evolución a otras enfermedades inflamatorias en una cohorte del noroccidente colombiano: Estudio observacional

Introduction: Undifferentiated arthritis is an inflammatory arthropathy that does not meet the criteria of specific rheumatological diseases and whose symptoms persist for one year. These individuals may spontaneously remit or evolve to another defined arthropa-thy, especially rheumatoid arthritis. The aim of this study was to describe the clinical and laboratory characteristics, both baseline and follow-up, of patients with undifferentiated arthritis in a reference center. Materials and methods: A retrospective descriptive study was conducted with patients with undifferentiated arthritis defined by rheumatologist criteria. Sociodemographic, clinical and therapeutic variables were analyzed. The qualitative variables were expressed as absolute and relative frequencies and the quantitative variables with median and inter-quartile range. Results: 66 patients were included; the median age was 46.3 years (IQR: 37.5-51.8); 10 subjects (15.2 %) had a family history of rheumatoid arthritis. Forty individuals (60.6 %) had involvement in proximal interphalangeal joints; the main symptom was morning sti-ffness in 29 patients (44 %). The most frequent extra-articular involvement was cutaneous (n = 14, 21.2 %). Non-steroidal anti-inflammatory drugs (n=18; 27.2%) and steroids (n=15; 22.7 %) were the most frequent treatments. Of 43 patients, 22 (51.2 %) remained with a diagnosis of undifferentiated arthritis, 18 (41.9 %) progressed to other diseases, the most frequent being rheumatoid arthritis, and in three (7 %) there was disease remission. Conclusions: In a cohort of patients with undifferentiated arthritis from northwestern Co-lombia, after 12 months, most of them persist with this diagnosis; it was striking the important frequency of a family history of rheumatoid arthritis and a low spontaneous remission.