USE OF LED LIGHT AND PHOTOBIOMODULATING THERAPIES IN THE CONTROL OF SEVERE ACNE AND ROSACEA

Abstract

Introduction: Severe acne and rosacea are chronic inflammatory dermatological conditions with significant impacts on quality of life. Conventional therapies, such as antibiotics and retinoids, often present side effects or resistance, driving the search for alternatives. In this context, the use of LED light and photobiomodulatory therapies has gained prominence, based on mechanisms such as modulation of the inflammatory response, reduction of sebaceous gland activity and bactericidal action. Recent studies have highlighted the potential of these technologies to regulate cellular processes, such as the production of reactive oxygen species and the expression of pro-inflammatory cytokines, offering a non-invasive and complementary approach. Despite the growing interest, gaps persist regarding the standardization of protocols and comparative efficacy between different wavelengths. Objective: This systematic literature review aimed to evaluate the clinical efficacy and safety of the use of LED light and photobiomodulatory therapies in the control of severe acne and rosacea, in addition to identifying optimized application parameters and possible synergies with conventional treatments. Methodology: The review followed the PRISMA checklist, using the PubMed, Scielo and Web of Science databases. The descriptors were: "LED therapy", "photobiomodulation", "acne vulgaris", "rosacea" and "low-level light therapy". Clinical studies published in the last 10 years, in humans, with full text available in English, Portuguese or Spanish were included. Exclusion criteria included animal studies, narrative reviews and articles without quantitative data. The screening resulted in 28 eligible articles, analyzed for clinical outcomes, protocols and safety. Results: The studies showed that blue (415 nm) and red (630 nm) light reduced inflammatory lesions by up to 70% in cases of acne, while amber light (590 nm) showed efficacy in attenuating erythema in rosacea. Protocols combining LED with photosensitizers or topical therapies improved results. Photobiomodulation at near-infrared wavelengths (850 nm) demonstrated profound anti-inflammatory effects, with minimal thermal risk. However, methodological heterogeneity limited direct comparisons, and most studies lacked long-term follow-up. Conclusion: LED light and photobiomodulatory therapies have emerged as promising, safe, and adjuvant strategies in the management of severe acne and rosacea, with mechanisms of action that complement traditional treatments. Optimization of parameters such as dose, duration, and combination of wavelengths requires further investigation for clinical standardization. Integration of these technologies into dermatological practice may reduce drug dependence, minimizing adverse effects, and improving therapeutic adherence.