Background: The role of preceding infections in the development of reactive arthritis (ReA) is well known but is less studied in association with other inflammatory arthritides. Therefore, in 1979-80 we screened for infections in patients with early musculoskeletal symptoms who were referred for rheumatological consultation and assessed the role of infections and other clinical factors in the development of chronic disease in following 14 years.

Methods: A total of 104 consecutive patients with suspected inflammatory musculoskeletal symptoms with a duration < 6 months were examined and screened for preceding infections in an outpatient rheumatology clinic. Follow-up evaluation was conducted after 14 years.

Results: ReA, undifferentiated arthritis, and rheumatoid arthritis were the most common diagnoses at baseline and at the 14-year follow-up. Of the 80 patients participating in the 14-year follow-up evaluation, 34 (42.5%) had had evidence of infection at baseline. Twenty-four patients (30%) had developed chronic rheumatic disease. Polyarticular disease at baseline and positive rheumatoid factors predicted the development of chronic diseases. Of the patients originally diagnosed with ReA, 7.3% proceeded to ankylosing spondylitis.

Conclusions: At baseline, signs of preceding infections were detected in 41% of the patients with early musculoskeletal symptoms. Preceding infections showed no association with either specific diagnosis of arthritis, except for ReA. Background: Not applicable.