Objective
This review aims to evaluate the effectiveness and safety of cupping therapy in patients with CU.

Search strategy
The search strategy looked for the presence of related keywords, such as “chronic urticaria” and “cupping therapy,” in the title and abstract of research articles indexed in major databases. Randomized controlled trials (RCTs) were selected after querying nine electronic databases from their inception to May 2019 with the above search terms.

Inclusion criteria
RCTs were included if they recruited patients with CU who were intervened with dry or wet cupping. Publications could be written in Chinese or English.

Data extraction and analysis
Data were extracted, and the studies were assessed for the quality of their methodological design and risk of bias. Meta-analyses of the RCT data were conducted to assess the total effective rate of the treatment as the primary outcome. Skin disease quality of life index score, recurrence rate, and adverse events were assessed as secondary outcomes. Subgroup analyses were conducted based on different interventions.

Results
Thirteen comparisons from 12 RCTs involving 842 participants were included. There were no significant differences between wet cupping and medications in total effective rate (n = 372; risk ratio [RR] = 1.10, 95% confidence interval [CI] 0.97 to 1.25; P = 0.14) or recurrence rate (n = 240; RR = 0.56, 95% CI 0.23 to 1.36; P = 0.20). Cupping therapy, in combination with antihistamine treatment was more efficacious than antihistamines alone, with a greater total effective rate (n = 342; RR = 1.18, 95% CI 1.01 to 1.39; P = 0.03) and lower recurrence rate (n = 342; RR = 0.52, 95% CI 0.32 to 0.84; P = 0.007). Cupping therapy combined with acupuncture was more effective than acupuncture alone (n = 156; RR = 1.25, 95% CI 1.07 to 1.46; P = 0.006). No serious adverse events were reported.

Conclusion
Wet cupping may be as effective as treatment with antihistamines. When cupping therapy is used as an adjuvant therapy to antihistamines or acupuncture, it may enhance the efficacy. Results drawn from these studies should be interpreted with caution and applied with care to clinical practice, because of the poor quality among the studies that were reviewed.

Key words: Cupping, Chronic urticaria, Systematic review, Meta-analysis, Antihistamines, Acupuncture