Comparison of the Efficacy and Safety of Delicate Pulsed Light and Q-Switched 1064 nm Nd:YAG Laser in the Treatment of Post-Acne Erythema

Acne vulgaris is a common chronic dermatological condition, affecting approximately 85% of adolescents worldwide and ranking eighth among all chronic diseases. Its exacerbation is often associated with recurrent lesions, inadequate treatment, and poor skincare habits such as squeezing or scratching, which frequently lead to the development of post-acne erythema (PAE). PAE is a vascular lesion located beneath the surface of the skin, characterized by a red appearance due to the clustering of dilated capillaries. Although PAE typically improves within 2 to 6 months, it may persist longer in some cases and even result in post-inflammatory hyperpigmentation. This is particularly prevalent in individuals with darker skin tones, where the incidence of PAE and hyperpigmentation ranges from approximately 45.5% to 87.2%. Facial acne not only affects physical appearance but also significantly impairs social interactions and can lead to psychological distress, including low self-esteem and depression. Low-energy, large-spot 1064 nm Nd:YAG laser, which belongs to the near-infrared spectrum, has deeper skin penetration and can effectively target deeper dermal tissues. In the treatment of PAE, the laser energy is absorbed by dilated microvasculature in the skin, promoting vasoconstriction and reducing localized redness and swelling. The low energy setting minimizes thermal damage while stimulating collagen production, thereby enhancing skin repair and improving the appearance of erythema. Delicate Pulsed Light (DPL) operates by emitting pulses of light at specific wavelengths that selectively target skin chromophores. In treating PAE, DPL precisely controls the wavelength and pulse intensity to target dilated blood vessels, thereby alleviating redness and inflammation. Additionally, DPL stimulates the skin's natural repair mechanisms and promotes collagen synthesis, accelerating the resolution of erythema and enhancing overall skin texture. Compared with conventional Intense Pulsed Light (IPL), DPL offers more accurate light modulation, fewer side effects, and better adaptability to various skin types and conditions. In this study, we conducted a split-face randomized controlled trial to compare the clinical efficacy and safety of low-energy large-spot 1064 nm Nd:YAG laser and DPL in treating acne and PAE. We aimed to explore whether there are significant differences between these two modalities in terms of clinical outcomes for post-acne erythema.