124 Effects of Long-pulsed Alexandrite Laser treatment on Microbiome in Rosacea Patients

Rosacea is a common cutaneous condition characterized by erythema and vasodilation on the face. Facial flushing and telangiectasia are common symptoms of rosacea, which respond well to treatments with lasers with wavelengths that are selectively absorbed by oxyhemoglobin, such as the pulsed-dye laser (PDL), intense pulsed light (IPL), long-pulsed Nd:YAG and Alexandrite. Additionally, there have been increased data on microbiome diversity imbalance in rosacea patients. The current study was designed to investigate the efficacy and mechanism of long-pulsed Alexandrite laser (LPAL) in rosacea patients by analyzing the facial microbiome in patients receiving laser treatment. Twenty-one patients were examined and treated every three weeks for three total treatments. The facial microbiome was analyzed by 16s rRNA amplicon sequencing, and all patients answered The Sensitive Scale-10 (TSS-10) and Dermatology Life Quality Index (DLQI) on their first and last visits. The erythema index significantly decreased after three sessions of LPAL in 3 weeks intervals, and the reduction of the erythema index was well maintained on both sides. LPAL treatment resulted in significant improvement in TSS-10 and the DLQI index. The composition and dynamics of the facial microbiome showed alteration after the treatment, yet the change was not significant. LPAL improved rosacea symptoms and patient perceptions, yet it did not affect microbial diversity.