Skin Microbiome and Inflammatory Skin Diseases: A Systematic Review of Clinical Evidence

Abstract

Introduction: The human skin microbiome constitutes a complex ecosystem of resident microorganisms that play a fundamental role in immunological homeostasis and skin barrier protection. The alteration of this microbial balance, known as dysbiosis, has been closely associated with the pathogenesis of various chronic inflammatory skin diseases, such as atopic dermatitis, psoriasis, acne vulgaris, and rosacea. Objective: To evaluate the clinicopathological relationship between the skin microbiome and major inflammatory skin diseases, analyzing the impact of dysbiosis and therapeutic strategies based on microbial modulation. Methodology: A systematic review of scientific literature published between 2018 and 2026 was conducted across PubMed/MEDLINE, Scopus, Web of Science, and The Cochrane Library databases, strictly adhering to PRISMA guidelines and evaluating risk of bias using the Cochrane RoB 2 tool. Results: Evidence demonstrates a marked loss of microbial diversity and an overgrowth of specific pathogens such as Staphylococcus aureus in atopic dermatitis and Cutibacterium acnes in hyperinflammatory acne strains which trigger inflammatory cascades through the activation of Toll-like receptors (TLRs). Interventions based on topical probiotics, prebiotics, and microbiome transplants demonstrated favorable modulation of the local immune response and restoration of the skin barrier. Conclusions: The skin microbiome is a critical component in the pathophysiology of inflammatory dermatoses. Its understanding opens the door toward precision dermatology focused on restoring skin ecological balance as a complementary therapeutic strategy.