LB967 Effects of a topical atopic dermatitis lotion on the skin microbiome and associations with skin barrier and itch

Abstract

Introduction: Atopic Dermatitis (AD) lesions have decreased skin microbial diversity and dominant colonization by Staphylococcus aureus. Several studies also reported increased microbial diversity and improvement in disease severity with treatment. Nonetheless, the role of skin microbiota in the pathogenesis of AD remains poorly understood. Materials & Methods: This clinical trial examined effects of topical lotions on changes in the skin microbiota, AD severity, skin barrier and itch. 61 healthy subjects with mild to moderate AD were studied over 14 days of twice-daily use of a topical AD cream formulated or a non-fragranced lotion. Efficacy and tolerance was measured by clinical evaluations, non-invasive measures of skin barrier and skin microbiota, and self-assessments. Results: At baseline, lesional skin had a higher pH, TEWL and lower skin hydration than non-lesional skin. For subjects treated with AD cream, disease severity significantly improved from baseline throughout the 14-day treatment. Both lesional and non-lesional skin had significant increases in hydration along with reduced pH, TEWL and itch, in contrast to minimal improvements following use of non-fragranced lotion. At baseline, skin microbial communities of non-lesional skin had significantly greater diversity than lesional skin (Chao1 and Shannon indices). Throughout the 14-day treatment with AD cream, but not with non-fragranced lotion, there were significant improvements in microbial diversity of lesional skin. Conclusion: Here we report that treatment with an AD cream improved AD disease severity along with a corresponding increase in microbial diversity in lesional skin, which converged to a profile similar to non-lesional skin. These data confirm previously identified linkages between microbial diversity and AD severity, while extending current knowledge of various microbial populations present in AD lesional skin, which may aid in development of new microbiome-based therapies.