For some years, blue light at a wavelength of 400–500 nm has emerged as a non-invasive and innovative treatment in dermatology. This narrative review provides a comprehensive exploration of the mechanisms by which blue light exerts therapeutic effects on various skin disorders including treatment of acne vulgaris, psoriasis, atopic dermatitis, vitiligo, androgenetic alopecia, ulcers and photoaging. We delve into the antimicrobial properties of blue light, highlighting its ability to generate reactive oxygen species that target and destroy pathogenic microorganisms such as Cutibacterium acnes. Additionally, we examine its anti-inflammatory effects, which involve the modulation of cytokine production and reduction in inflammatory cell infiltration, contributing to symptom relief in chronic inflammatory conditions. Blue light, through interaction with some photoreceptors, belonging to the Opsin family, is able to stimulate and prolong the anagen phase in the hair’s life cycle and stimulate repigmentation in vitiligoid patches. The photobiomodulation properties of blue light are also discussed, emphasizing how it influences cellular activities like proliferation and differentiation, thereby aiding in skin rejuvenation and healing processes. By assessing the clinical efficacy, safety profiles, and potential adverse effects reported in the current literature, we aim to present a balanced perspective on the utility of blue light therapy. The review also discusses advancements in light-emitting diode (LED) technology that have enhanced treatment delivery and patient outcomes. Furthermore, we outline future directions for research and clinical applications, emphasizing the need for standardized treatment protocols and long-term safety studies to fully integrate blue light therapy into dermatological practice.

Cutaneous aging is characterized by gradual structural and functional alterations, including collagen breakdown and reduced elasticity. In recent years, several energy-based modalities have been introduced to address these changes. The aim of this study was to assess the effectiveness of a 675 nm laser and microfocused ultrasound (MFU), applied individually or in combination, for the treatment of facial aging. This retrospective analysis included 115 patients, allocated into three groups: Group A (675 nm laser), Group B (MFU), and Group C (combined protocol). Efficacy was evaluated through the Fitzpatrick Wrinkle Scale (FWS), the Baker Gravitational Ptosis Classification (BGP), and standardized photographic assessments at 1, 3, and 6 months following treatment. At the 6-month evaluation, individuals treated with the combined protocol exhibited a more pronounced improvement in wrinkle reduction (FWS: from 1.88 to 1.13) and laxity reduction (BGP: from 2.78 to 1.55) compared with either single-treatment group. No major side effects were observed. The combined application of the 675 nm laser and MFU appears to potentiate collagen remodeling and skin tightening more effectively than monotherapy. Further prospective studies are needed to validate these results and further clarify the molecular pathways involved.