Effect of emollients on skin barrier function in patients with atopic dermatitis: a systematic review and meta-analysis.

Abstract

Introduction: Atopic dermatitis (AD) primarily arises from skin barrier dysfunction. Emollients serve as a primary management modality for AD patients. They can enhance skin barrier function through multiple mechanisms. However, previous research has not established definitive conclusions about their effectiveness or ideal usage duration. This study systematically analyzes emollients' actual barrier-repairing effects by synthesizing current evidence.

Methods: We screened 14 relevant studies from four databases: PubMed, Embase, Web of Science, and Cochrane Library. Ten of these human randomized controlled trials were included in the meta-analysis, which mainly examined the effects of emollients on transepidermal water loss (TEWL), skin hydration (capacitance value), and skin acidity (pH). We further compared the effects of different application times on TEWL in subgroups. Data were analyzed using Review Manager 5.4, and the results are expressed as effect estimates with 95% confidence intervals (CIs).

Results: The TEWL values of AD patients using emollients were significantly lower than those of the control group, with statistical significance at 2 weeks and 4 weeks of continuous use. Skin capacitance values were significantly higher in the emollient group than in the control group, and there was no significant difference in skin pH between the two groups of patients.

Conclusions: The combined data suggest that emollients can reduce TEWL values and improve skin hydration in patients with AD, with statistically significant effects observed after 2 weeks and 4 weeks of continuous use. However, the improvement of skin pH by emollients has not been confirmed, and the efficacy of use for ≥6 weeks remains inconclusive due to limited evidence. More research is needed to explore this in the future.