Barrier Protection, Skin Microbiome, and Diaper Dermatitis in Infants: Current Evidence and Future Perspectives—A Narrative Review

Diaper dermatitis is one of the most common inflammatory skin conditions in infancy. It develops through the combined effects of moisture, friction, irritants, and disruption of the epidermal barrier. This review aimed to evaluate recent evidence on barrier-supportive ingredients used in infant diaper care, with a focus on barrier protection, microbiome-related approaches, and their role in preventing and managing diaper dermatitis. A structured literature search of PubMed, Scopus, and Web of Science identified clinical studies involving infants and young children of diaper-wearing age that evaluated diaper-area interventions or implementation strategies and reported diaper dermatitis or related skin outcomes, including erythema, transepidermal water loss, skin pH, and hydration. The final clinical evidence synthesis included 35 independent studies reported in 34 publications. Reviews and relevant experimental or mechanistic studies were used to provide background and biological context but were not considered direct evidence of clinical efficacy in infants. Clinical findings were synthesized narratively according to intervention type, study design, population, outcomes, and key limitations. Direct clinical evidence supports barrier-protective care, appropriate cleansing practices, and diaper-related strategies as core components of diaper dermatitis prevention and management, although findings varied by formulation, population, and outcome. Evidence for botanical and natural topical interventions was formulation-specific and inconsistent across studies. Microbiome-targeted approaches, including postbiotics, are biologically plausible and supported primarily by experimental and mechanistic evidence; however, direct clinical evidence in infant diaper dermatitis remains limited.