Quantitative Evaluation of Treatment Efficacy in Papulopustular Rosacea Using High‐Frequency Ultrasound Combined With Ultra‐Micro Angiography Technology

OBJECTIVES: This study aims to apply high-frequency ultrasound (HFUS) in conjunction with ultra-micro angiography (UMA) technology to observe the ultrasound characteristics of facial lesions in patients with papulopustular rosacea (PPR). It will also quantitatively evaluate the changes before and after treatment, thereby assessing the feasibility and application value of this combined technique in evaluating the treatment efficacy for PPR. METHODS: We conducted a prospective study involving 63 patients with PPR who visited the dermatology department between May 2024 and March 2025. Two attending dermatologists independently evaluated the most severe lesions on each patient's cheeks (marked area) and performed follow-up evaluations at the end of the fourth week of treatment, as well as calculated the therapeutic efficacy index. We utilized HFUS, equipped with a 33 Hz linear array probe, in conjunction with UMA technology to conduct ultrasound scans of the marked areas of patients at baseline and at the end of the fourth week of treatment. This allowed us to obtain ultrasound characteristics and perform statistical analyses. RESULTS: The dermatologists classified the PPR patients based on the therapeutic efficacy index into cured (6 cases), significantly improved (23 cases), improved (29 cases), and ineffective (5 cases). By the end of the fourth week of treatment, significant changes were observed in non-quantitative features, including epidermal morphology, the subepidermal low-echogenic band, dermal echogenicity, sebaceous gland echogenicity, and the echoes of inflammatory papules, compared to baseline (p < .01). Simultaneously, quantitative parameters, including thickness ratio, maximum diameter of hair follicles, maximum diameter of facial skin microvessels, peak systolic velocity, time average maximum velocity, and color pixel percentage (CPP), all significantly decreased (p < .01). Spearman correlation analysis indicated a strong correlation between quantitative parameters, such as CPP and the relative change ratio of color pixel percentage, and the therapeutic efficacy index at the end of the fourth week of treatment (0.70 ≤ |r| < 0.90, p < .01). CONCLUSIONS: HFUS combined with UMA technology can be effectively used for the quantitative evaluation of treatment efficacy in PPR.