Increased Risk of Systemic Lupus Erythematosus in Patients with Chronic Urticaria: A Systematic Review and Meta-analysis

INTRODUCTION: The association between systemic lupus erythematosus (SLE) and chronic urticaria (CU) has been suggested in the literature although the amount of evidence is still relatively limited. We aimed to combine all available studies on this association using systematic review and meta-analysis technique. METHODS: Potentially eligible studies were identified from Medline and EMBASE from inception to February 2023 using search strategy that comprised of terms for “chronic urticaria” and “systemic lupus erythematosus”. The eligible study must consist of one group of patients with CU and another group of comparators without CU and must compare the prevalence of SLE in each group and report effect size with 95% confidence intervals (95% CIs). We extracted such data from each study to calculate a pooled odds ratio using the generic inverse variance method with random-effect model. Funnel plot was used to evaluate publication bias. Newcastle-Ottawa Scale was used to appraise the methodological quality of the included studies. RESULTS: A total of 5,155 articles were identified. After two rounds of independent review by four investigators, five studies met the eligibility criteria and were included in the meta-analysis. The meta-analysis found an increased prevalence of SLE among patients with CU compared with individuals without CU with the pooled odds ratio of 5.03 (95% CI, 2.57–9.85, I2 of 93%). CONCLUSION: This systematic review and meta-analysis found that patients with CU had a significantly increased risk of SLE compared to individuals without CU.