Meta-Analysis of Heat-Clearing and Dampness-Resolving Chinese Herbal Medicines in Treating Atopic Dermatitis Animal Models

Objective: This study employed meta-analysis to systematically evaluate the therapeutic efficacy of heat-clearing and dampness-resolving Chinese herbal medicines interventions in animal models (rats or mice) of atopic dermatitis (AD), thereby providing evidence-based support for the clinical treatment of damp-heat pattern AD. Methods: A computerized search was conducted in PubMed, Embase, Web of Science, The Cochrane Library, CNKI, CBM, Wanfang Data, and VIP databases to collect randomized controlled trial data on Chinese herbal medicines with heat-clearing and dampness-resolving properties for treating rat or mouse models of atopic dermatitis. The search period spanned from the inception of each database to June 19,2025. The intervention group received heat-clearing and dampness-resolving Chinese herbal medicines treatment without formulation restrictions, while the control group received conventional Western medication alone. The SYRCLE tool was used to assess the risk of bias in included studies. Quality assessment was conducted in accordance with the Cochrane Handbook for Systematic Reviews. Statistical analysis was performed using Review Manager 5.4 and Stata 18.0 software. Results: A total of 16 randomized controlled trials were ultimately included, covering BALB/c mice, KM mice, Flaky tail mice, Nc/Nga mice, and C57BL/6 mice. Meta-analysis results indicate that heat-clearing and dampness-resolving Chinese herbal medicines can reduce skin lesion scores in atopic dermatitis mice (SMD = 0.11, 95% CI = -0.73–0.94, P = 0.80), decrease scratching frequency (SMD = 0.33, 95% CI = -0.55–1.21, P = 0.47), decrease the number of mast cells in skin lesions (SMD = 0.68, 95% CI = -0.19–1.55, P = 0.12), and downregulate serum IgE (SMD = -0.13, 95% CI = -0.55–0.29, P = 0.54) and IL-4 (SMD = 0.09, 95% CI = -1.17–1.35, P = 0.89). None of these differences were statistically significant, indicating that the treatment effects were comparable between the experimental and control groups. The spleen coefficient (SMD = 4.53, 95% CI = 2.77–6.29, P<0.00001) and epidermal thickness at the lesion site (SMD = 1.84, 95% CI = 0.82–2.85, P = 0.0004) in control mice were significantly lower than those in the experimental group. Serum IL-10 levels (SMD = -1.40, 95% CI = -2.45–-0.34, P = 0.009) were significantly higher in control mice compared to experimental mice, with statistically significant differences. Conclusion: Chinese herbal medicines with heat-clearing and dampness-resolving properties can improve skin lesions in AD mice, downregulate serum IgE and IL-4 levels, reduce the number of mast cells in lesions, alleviate skin itching, and thereby relieve AD symptoms. Given the overall low quality and high heterogeneity of the included studies, further high-quality clinical trials or animal studies are still needed in the future.