Focused Ultrasound Followed by Radiofrequency Microneedling with Bacteria-derived Extracellular Vesicle for Melasma and Skin Aging: A Retrospective Case Series

Background : Melasma and facial skin aging are multifactorial conditions involving pigmentary, inflammatory, vascular, and dermal remodeling pathways. Combination energy-based device (EBD) protocols are designed to target multiple pathways in a single treatment course. However, real-world data on focused ultrasound and radiofrequency (RF) microneedling combined with exosome delivery, for managing melasma and facial skin aging are limited. Case Presentation : This is a retrospective, single-center case series of four patients aged 50 to 60 years with Fitzpatrick skin phototypes III to IV, presenting with mixed-type melasma, and facial skin aging. During the first session, each patient received dot-mode focused ultrasound (LinearZ) followed 30 minutes later by monopolar RF microneedling (POTENZA) with 1.5 mL of a bacteria-derived extracellular vesicle solution (RexoFace). Patients subsequently received one or two additional RF microneedling sessions at 6-week intervals. Thus, the interval from baseline to the final 4-week post-treatment assessment was approximately 10 weeks for patients receiving two RF sessions and 16 weeks for the patient receiving three RF sessions. Outcomes were assessed descriptively on standardized clinical photographs and images obtained with the Sylton OBSERV 520x imaging platform at baseline and 4 weeks after the final session. All four patients showed investigator-assessed improvement in melasma pigmentation, skin quality, and clinical signs of facial aging. Assessment was unblinded and no validated severity instrument was applied. Mild to moderate erythema with edema followed each RF microneedling session and decreased without intervention within 45 minutes. No serious adverse events, scarring, infection, or post-inflammatory hyperpigmentation were recorded during the 4-week observation period. Since the follow-up was limited to 4 weeks after the final session, these observations do not establish medium-term cutaneous safety or durability. Conclusions : In this retrospective four-patient case series, the combined protocol of dot-mode focused ultrasound and monopolar RF microneedling with a bacteria-derived extracellular vesicle solution was associated with visible improvement and was well tolerated over a short observation period.