Supplement Article: The Role of Epidermal Barrier Dysfunction and Cutaneous Microbiome Dysbiosis in the Pathogenesis and Management of Acne Vulgaris and Rosacea.

Background: Dysregulation of either the cutaneous microbiome (CM) or epidermal barrier function (EBF) is thought to play an increasingly important role in acne vulgaris (AV) and rosacea pathogenesis.

Objective: To review the literature regarding epidermal barrier dysfunction (EBD) and cutaneous dysbiosis in AV and rosacea and provide clinical pearls for dermatologists.

Methods: A Medline literature search was performed for relevant literature regarding EBD and dysbiosis and either AV or rosacea. An expert consensus panel was then convened to discuss article merits and distill findings into clinical pearls.

Results: Final review included 138 articles. Puberty may alter natural stratum corneum lipid ratios, instigating and/or exacerbating EBD in AV. Patients with severe AV have an abundance of virulent Cutibacterium acnes phylotype IA1. EBD may manifest as classic signs of rosacea and improve with treatment. While several microbial populations are dysregulated in rosacea, the effect from any singular species is unclear. Current AV and rosacea treatment regimens may mitigate inflammation but may also indiscriminately damage CM and EBF. Physiologic moisturizers and cleansers that harness pre-/pro-/postbiotics may have a role in restoring CM, EBF, and potentially improving dermatosis severity.

Limitations: Limited prospective clinical trial data especially regarding over-the-counter (OTC)/non-prescription skincare products.

Conclusion: Appropriately developed prescription and OTC preparations may selectively influence the microbiome and potentially maintain/restore EBF. By understanding this relationship, dermatologists will be better able to educate patients on the importance of appropriate skin care.J Drugs Dermatol. 2022;21:9(Suppl 2):s5-14.