BACKGROUND: Picosecond lasers are increasingly being investigated in treating pigmentation disorders because they may provide better treatment efficacy and comfort compared with nanosecond lasers. OBJECTIVE: This study aims to evaluate the efficacy and side effect of a novel 670-nm picosecond laser in the removal of benign pigmented lesions (BPLs) in individuals with Fitzpatrick skin types (FST) III and IV. MATERIALS AND METHODS: Fifteen subjects with solar lentigines and 7 subjects with ABNOMs received a single treatment with a 670-nm picosecond laser. Blinded physicians assessed the pigment clearance using a 5-category grading system scale. All subjects were evaluated at 1 month, 3 month, and 6 month after a single treatment. Adverse events were recorded at every follow-up visit. RESULTS: All subjects with lentigines had complete clearance (95%–100%) of lesions during 3-month follow-up after a single treatment session of 670-nm picosecond laser, whereas 75% of the subjects with ABNOMs noted fair lightning (25%–49%) of lesions. Mild hypopigmentation and hyperpigmentation were observed in 9% and 14% of the subjects, respectively, which resolved within 3 months after the treatment. CONCLUSION: The novel 670-nm picosecond laser is a safe and effective treatment for BPLs in subjects with FST III and IV with low rates of transient adverse effects.

Objective Botulinum toxin serotype A (BoNT/A) is widely used for minimal invasive aesthetic treatments. Different brands of BoNT/A exhibit structural variations. The aim of this study was to compare the duration and efficacy of various BoNT/A brands available in Thailand for reducing bite force and treating wrinkles. Methods Fifty participants were randomly assigned to one of five groups, with each group receiving a different BoNT/A brand, namely, incobotulinumtoxinA (IncoA), onabotulinumtoxinA (OnaA), abobotulinumtoxinA (AboA), letibotulinumtoxinA (LetiA), and prabotulinumtoxinA (PraboA). BoNT/A was administered to the masseter muscle and the upper face. Bite force was measured before injection and at 2, 4, 8, 12, 16, 20, and 24 weeks post-injection. Evaluation scores for wrinkle improvement were assessed after the treatment. Results The most significant reduction in bite force occurred between 2 and 4 weeks post-injection. PraboA demonstrated the most substantial reduction in bite force, while IncoA had the least effect. However, the percentage of bite force reduction did not exhibit statistical significance between BoNT/A types. Additionally, the reduction in bite force for all BoNT/A types was reversed at 4 months post-injection. More than half of the participants experienced improvement beyond 16 weeks. Conclusions The structural differences among BoNT/A brands did not significantly affect the longevity and efficacy of bite force reduction and wrinkle treatment. Trial Registration ClinicalTrials.gov identifier: TCTR20211205001 (registered 4 Dec 2021).

Background: Melasma is an acquired hyperpigmentation disorder with multifactorial etiologies and limited response to conventional therapies. Recent evidence suggests that Botulinum Toxin A (BoNT-A) may modulate ultraviolet (UV)-induced pigmentation and offer therapeutic benefits. Objective: We sought to evaluate the efficacy and safety of two intradermal dilutions of Letibotulinum toxin A (LetiBoNT-A) in Thai patients with melasma. Methods: In this randomized, double-blind, split-face study, 30 participants aged 32–62 years received a single intradermal injection of LetiBoNT-A, with 20 units administered per cheek. A 1:5 dilution was injected on one side of the face, and a 1:10 dilution was injected on the contralateral side. Outcomes were evaluated over a 6-month period using the Hemi-modified Melasma Area and Severity Index (Hemi-mMASI), VISIA^® brown spot analysis, and quantitative assessments of skin texture. Results: Both dilutions significantly improved Hemi-mMASI scores (1:5, p = 0.043; 1:10, p = 0.002) and brown spots (1:5, p = 0.002; 1:10, p < 0.001). The 1:10 dilution showed earlier and more sustained improvements. Subgroup analysis revealed greater reductions in Hemi-mMASI scores among patients with telangiectatic melasma, particularly with the 1:10 dilution, though they were not statistically significant. Additionally, the 1:10 dilution significantly reduced pore volume, pore area, and sebum levels. One case of transient facial asymmetry was reported with the 1:5 dilution. Conclusions: LetiBoNT-A is a safe and effective adjunct in melasma treatment. The 1:10 dilution offered superior clinical outcomes.

The neck is a challenging area for aesthetic rejuvenation due to its thin dermis and the risk of nodule formation associated with traditional particulate fillers. A novel, liquid-type polycaprolactone (PCL) offers a potential alternative by mitigating these risks. To evaluate the clinical efficacy and safety of liquid-type PCL for the treatment of horizontal neck lines in Asian patients. In this prospective, open-label, single-arm pilot study, 30 Asian subjects received three sessions of liquid-type PCL (GOURI; 210 mg/mL, 21% PCL) injections at one-month intervals using a subdermal cannula technique. All participants completed the treatment series; follow-up data were available for 29 participants at 1 month and 28 participants at both 3 and 6 months after completion of treatment. Objective biophysical parameters, including skin elasticity (Cutometer) and skin texture/wrinkle depth (Antera 3D), were assessed over a 6-month follow-up period. Subjective satisfaction and safety were also evaluated. Visual and quantitative assessments demonstrated measurable improvement in horizontal neck lines and skin quality over 6 months. In participant-level paired analyses, skin distensibility (R0) decreased from 0.214 ± 0.089 at baseline to 0.102 ± 0.091 at 6 months (mean change, −0.109; 95% CI, −0.152 to −0.066; standardized mean change [Cohen’s dz], −1.03; p < 0.001). Gross elasticity (R2) changed from 66.66 ± 15.72 to 38.16 ± 29.35 (mean change, −28.68; 95% CI, −40.70 to −16.67; dz, −0.93; p < 0.001). Skin roughness, volume of depression, and melanin index also decreased significantly. At 6 months, 85% of participants with available follow-up data reported ≥ 51% improvement. The treatment was generally well tolerated; one participant developed mild bruising that resolved spontaneously within 8 days. Liquid-type PCL may represent a safe and minimally invasive option for neck rejuvenation in appropriately selected patients. These pilot data suggest measurable improvement in neck skin texture, firmness-related parameters, and pigmentation; however, controlled studies with longer follow-up and blinded evaluation are required to confirm efficacy, durability, and optimal candidate selection.

Autologous platelet-rich plasma (PRP) regenerative properties are used to treat clinical manifestations of skin aging. This study assessed the efficacy and safety of photothermal biomodulated PRP (PTBM-PRP) compared to standard PRP for skin rejuvenation. Prospective, split-face, randomized study including Thai volunteers (30–60 years) with Fitzpatrick skin type III-IV and moderate severity photoaging or higher conducted at Siriraj Hospital (Bangkok, Thailand). Face sides were randomized to receive intradermal autologous PTBM-PRP or PRP injections in three sessions at one-month intervals, with follow-up visits at one, three, and six months. PRP was preconditioned using the MCT System (Meta Cell Technology, Sant Cugat del Vallès, Spain) preset with the Exosomes program (467 nm continuous light [1 J/cm ² ], 37 °C, 10 min). We evaluated changes in skin surface characteristics, pigmentation, redness, and biomechanical properties (i.e., firmness, elasticity, and viscoelasticity), perceived facial improvement, and perceived pain. We included 28 volunteers (96.4% women) with a mean (SD) age of 40.82 (8.95) years and mostly skin type IV (67.86%). PTBM-PRP decreased fine lines maximum depth ( p = 0.041) and indentation index ( p = 0.005), folds maximum depth ( p = 0.032) and indentation index ( p < 0.001), and wrinkles maximum depth ( p = 0.024) and indentation index ( p = 0.041) in the periorbital area. PRP transiently decreased folds indentation index ( p = 0.008) and wrinkles maximum depth ( p = 0.0499) (PTBM-PRP vs. PRP wrinkles maximum depth p = 0.038 and indentation p = 0.018). Improvements in pigmentation, redness, and biomechanical properties were similar for both treatments. Patients perceived both treatment effects mostly as good or excellent improvement, with slightly favorable pain scores for PTBM-PRP vs. PRP, particularly at visit 3 ( p = 0.006). Compared to standard PRP, PTBM-preconditioned PRP for facial skin rejuvenation results in greater improvements in fine lines, folds, and wrinkles parameters, with sustained effects for more than six months, supporting a PTBM protocol use to enhance the regenerative capacity of PRP in skin rejuvenation.

Lee SH, et al. Ann Dermatol. 2024 Apr;36(2):120-122. https://doi.org/10.5021/ad.21.101