Supplementary Material for: Long-Term Risk of Autoimmune Diseases other than Systemic Lupus Erythematosus in Cutaneous Lupus Erythematosus-Alone Patients: A 10-Year Nationwide Cohort Study

Background: Up to 25% of patients with cutaneous lupus erythematosus (CLE) can develop systemic lupus erythematosus (SLE). However, the risk of autoimmune diseases other than SLE in CLE patients who have only skin manifestations (CLE-alone) has rarely been explored. Objective: To investigate the long-term risk and independent factors of non-SLE autoimmune diseases among CLE-alone patients. Method: A nationwide cohort study using the Taiwanese National Health Insurance Research Database 1997–2013. CLE patients and matched subjects were included. Cumulative incidences of autoimmune diseases after 1 year of CLE-alone diagnosis were compared. Cox proportional hazard model was also performed. Results: A total of 971 CLE-alone patients and 5,175 reference subjects were identified. The 10-year cumulative incidence of autoimmune diseases other than SLE was significantly elevated in the CLE-alone cohort (9.00%, 95% confidence interval [CI] 6.72–11.29) than in the reference cohort (4.20%, 95% CI 3.53–4.87%) (p Conclusion: CLE-alone is independently associated with future non-SLE autoimmune diseases.