Efficacy of auricular bloodletting therapy for acute urticaria: A propensity score-matched retrospective cohort study

Acute urticaria is a common condition that can affect individuals across all age groups. Current pharmacological treatments primarily rely on antihistamines and corticosteroids. However, these therapies may be limited by suboptimal efficacy, dose- and time-dependence, and potential adverse effects. Therefore, the incorporation of effective adjunctive therapies is of considerable clinical value. This study aimed to evaluate the impact of auricular bloodletting (BL) therapy on the length of hospital stay in patients with acute urticaria. Poisson regression was used to compare differences in hospitalization duration between groups. Propensity score matching (PSM) was applied to minimize selection bias. Subgroup analyses by sex and age, as well as robustness checks using bootstrap resampling and Rosenbaum sensitivity analysis, were also performed. Before PSM, Poisson regression indicated that the bloodletting group had significantly shorter hospital stays. The effect was significant in the male, female, and adult subgroups. After PSM, the incidence rate ratios remained below 1 in all models, and statistical significance was observed. No significant differences were observed in the female or adult subgroups post-matching, whereas statistical significance was retained in the male subgroup. No adverse events were reported. Bootstrap and Rosenbaum sensitivity analyses confirmed the robustness of the findings. Patients who received auricular BL experienced shorter hospital stays. Post-matching results showed that statistical significance was retained in the male subgroup. Given the limited sample size in the intervention group, further prospective studies with larger cohorts are warranted to validate these findings and elucidate the underlying mechanisms.