Bloodletting Therapy for Patients with Chronic Urticaria: A Systematic Review and Meta-Analysis

Background. Many trials have reported that bloodletting therapy is effective when treating chronic urticaria. There are currently no systematic reviews of bloodletting therapy for chronic urticaria. Objective. The aim of this review is to assess the effectiveness and safety of bloodletting therapy for chronic urticaria. Methods. A systematic review and meta-analysis of randomized controlled trials were performed. Disease activity control was assessed as the primary outcome. Response rate, recurrence rate, and adverse events were assessed as secondary outcomes. Results. Seven studies with 512 participants were included. One trial showed a significant difference between bloodletting therapy plus medicine and medicine alone in disease activity control (MD 0.67; 95% CI 0.03 to 1.31; p=0.04). Six trials (372 participants) showed a significant difference between bloodletting therapy and pharmacological medication in response rate (RR 1.10; 95% CI 0.97-1.26; P =0.15). Two studies (170 participants) showed a significant difference between bloodletting therapy plus pharmacological medication and pharmacological medication in response rate (RR 1.34; 95% CI 1.10-1.63; p=0.003). Two studies (126 participants) reported a statistically significant difference between bloodletting therapy and pharmacological medication in recurrence rate. No serious adverse events related to bloodletting therapy were reported. Conclusions. Bloodletting therapy might be an effective and safe treatment for chronic urticaria, but the evidence is scarce. More high quality trials are needed in the future.