Comparison of the Efficacy of Low‐Energy Delicate Pulsed Light and Q‐Switched 1064 nm Nd:YAG Laser in the Treatment of Post‐Acne Erythema: A Prospective Randomized Split‐Face Study

ABSTRACT Objectives Post‐acne erythema (PAE), a common consequence of acne, is characterized by capillary dilation and erythema, which significantly impact facial aesthetics and quality of life. This study aims to evaluate and compare the efficacy and safety of intense pulsed light (DPL) and 1064 nm Q‐switched Nd:YAG laser in treating PAE. Methods This prospective, randomized, self‐controlled, evaluator‐blinded clinical trial compared DPL and 1064 nm Q‐switched Nd:YAG laser treatments on one side of the face, with biweekly sessions for 6 weeks. Patients were assessed during the treatment period using the VISIA 6.0 system, CEA scale, GAIS, and skin physiological parameters. Photographs were taken before and after each session, and adverse reactions and pain were recorded. Data analysis was performed using SPSS software, with p ‐values < 0.05 considered significant. Results A total of 26 patients were enrolled, all completing follow‐up. Both treatments significantly reduced PAE lesions ( p < 0.001) compared with baseline, with the DPL group showing more significant improvement from Week 8. After six treatments, both groups showed significant reductions in erythema index and red zone area ( p < 0.001), with no significant differences between the groups ( p > 0.05). The DPL group had significantly lower CEA scores at week 8 ( p < 0.043), but no significant difference was found at Week 12. Both treatments improved wrinkles ( p < 0.001), with the Nd:YAG group showing better skin elasticity recovery ( p = 0.044). GAIS scores indicated significant improvement in both treatments. Patient satisfaction was 92.31%, with the DPL group slightly higher. No pigmentation or depigmentation was observed, ensuring good safety. Conclusions Both DPL and low‐dose Q‐switched 1064 nm Nd:YAG laser effectively treat PAE. DPL yields better early results, while Q‐switched Nd:YAG laser improves skin retraction more effectively. Both are safe, well‐tolerated options for PAE therapy.