A new low‑energy, three‑pulse laser treatment (AOPT‑LTL) was tested on mice with LL‑37‑induced rosacea and on 23 people with facial redness. It reduced skin inflammation, blood‑vessel changes, and the key rosacea molecules in mice, and it improved redness and flushing in patients without serious side effects.

Rosacea is a chronic inflammatory skin disease affecting the face, and the current treatment effect is not satisfactory. Based on the photomodulation of optimal pulse technology (OPT), we developed a novel treatment mode, namely, advanced OPT with low energy, three pulses, and long pulse width (AOPT-LTL). We aimed to explore the feasibility and underlying molecular mechanisms of AOPT-LTL treatment in a rosacea-like mouse model. Furthermore, we evaluated the safety and efficacy in patients with erythematotelangiectatic rosacea (ETR). Morphological, histological, and immunohistochemical analyses were used to investigate the efficacy and mechanisms of AOPT-LTL treatment in the LL-37-induced rosacea-like mouse model. Moreover, 23 patients with ETR were included and received different times of treatment at intervals of 2 weeks depending on the severity of their condition. The treatment effect was assessed by comparing clinical photographs at baseline, 1 week, and 3 months after treatment, combined with the red value, GFSS, and CEA scores. After the AOPT-LTL treatment of the mice, we observed that the rosacea-like phenotype, inflammatory cell infiltration, and vascular abnormalities were significantly ameliorated, and the expression of the core molecules of rosacea was significantly inhibited. In the clinical study, the AOPT-LTL treatment exerted satisfactory therapeutic effects on erythema and flushing of ETR patients. No serious adverse events were observed. AOPT-LTL is a safe and effective method for the treatment of ETR.