Trigger finger and the risk of systemic inflammatory and autoimmune rheumatic diseases: real-world evidence.

BACKGROUND: Trigger finger (TF) is a common hand disorder traditionally viewed as a localized mechanical condition. Recent evidences suggests potential links between tenosynovial pathology and systemic inflammatory diseases, especially rheumatoid arthritis, though large-scale longitudinal data remain limited. METHODS: We conducted a retrospective cohort study using the TriNetX Global Collaborative Network. Adults diagnosed with TF between 2005 and 2018 were identified and compared with individuals undergoing routine health evaluations without TF. Patients with prior malignancy, systemic rheumatic diseases, or death before index were excluded. One-to-one propensity score matching balanced demographics, comorbidities, healthcare utilization, medications, and socioeconomic factors. The primary outcomes were incident systemic autoimmune and inflammatory rheumatic diseases, including inflammatory arthritis and connective tissue disorders. We estimated hazard ratios with 95% confidence intervals. Robustness was assessed through sensitivity analyses incorporating alternative matching strategies, extended washout periods, varying follow-up durations, and stricter exposure definitions, alongside subgroup analyses by age and sex. As validation, data from US Collaborative Network were also applied for analysis. RESULTS: After matching, 82,566 patients were included in each cohort. TF was associated with increased risks of ankylosing spondylitis (HR 1.973, 95% CI 1.377-2.828), rheumatoid arthritis (HR 1.604, 95% CI 1.287-1.998), psoriatic arthritis (HR 1.832, 95% CI 1.428-2.352), and gout (HR 1.152, 95% CI 1.053-1.261). Elevated risks were also observed for systemic lupus erythematosus (HR 1.460, 95% CI 1.146-1.858) and Sjögren syndrome (HR 1.314, 95% CI 1.077-1.604). Associations remained consistent across most sensitivity analyses, including extended washout periods and alternative cohort definitions. Subgroup analyses demonstrated similar patterns across age and sex strata. CONCLUSIONS: TF was associated with systemic autoimmune and inflammatory rheumatic diseases. Current findings support a potential link between localized tendon pathology and broader systemic inflammatory processes.