New Normal Mask-Wearing and Its Impact on Underneath Skin Microbiome: A Cross-Sectional Study in Mild Acne Vulgaris Patients

Introduction: Prolonged mask-wearing could modulate the skin microenvironment resulting in several facial dermatoses. Microbial dysbiosis is proposed to be linked with these changes; however, data regarding the association is still limited. Accordingly, we aimed to explore the impact of face masks on the skin's bacterial microbiota. Methods: We classified participants into short (<4 h/day) and long (>= 4 h/day) mask-wearing time (SMWT and LMWT) groups according to mask-wearing time per day in the previous 2 weeks. Specimens were swabbed from the cheek and forehead of 45 mild acne vulgaris patients, representing mask-covered area (MCA) and mask-uncovered area (MUA), respectively. The 16S rRNA gene sequencing and QIIME2 were used to characterize bacterial communities. Results: There were 12 (26.7%) and 33 (73.3%) participants in SMWT and LMWT, respectively. There were no significant differences in beta diversity across MCA/MUA or LMWT/SMWT groups. In alpha-diversity, the evenness on MCA was significantly lower in LMWT than in SMWT (p value = 0.049). Among all groups, the relative abundance of bacterial taxa was similar, showing Actinobacteriota and Firmicutes, and Cutibacterium and Staphylococcus as the most predominant phyla and genera, respectively. Conclusion: Our results showed no significant impact of mask-wearing on the skin microbiota in mild acne vulgaris participants.