A focused review on acne-induced and aesthetic procedure-related postinflammatory hyperpigmentation in Asians

Exploring Fractional Pigment Toning: A Novel Approach for Treating Benign Pigmented Lesions in Asian Patients With Fitzpatrick Skin Types III-V

BACKGROUND/OBJECTIVE

Laser therapy has emerged as a widely favored treatment option for solar lentigines (SL). However, a significant challenge associated with this treatment, particularly among individuals with darker skin tones, is the notable risk of postinflammatory hyperpigmentation (PIH) induction. In response to these concerns, the authors conducted a prospective, self-controlled study to comprehensively evaluate the safety and effectiveness of 532-nm picosecond laser, both with and without a microlens array (MLA), for the management of SL in patients with Fitzpatrick skin types (FST) III-V.

METHODS

Twenty-seven patients with FST III-V and bilateral SL on the face underwent randomized treatment. One side of the face was treated with a 532-nm picosecond laser coupled with an MLA, utilizing the fractional pigment toning (FPT) technique, while the other side received treatment without the MLA, following the conventional technique (CT). The FPT technique utilized a 9-mm spot size with a fluence of 0.47 J/cm2 for two passes covering 40% of the area. In contrast, the CT used a 4.5-mm handpiece with fluence ranging from 0.3 to 0.7 J/cm2. Patients received a single treatment and were evaluated for pigment clearance, occurrence of PIH, and other adverse effects at 2 weeks, 1, 3, and 6 months posttreatment.

RESULTS

Twenty-seven participants completed the study protocol. Analysis of pigment clearance, measured via 3D photography, showed significant improvement from 2 weeks to 6 months posttreatment for both the FPT technique (p < 0.001) and CT (p = 0.004). PIH occurred in 64%, 80%, 96%, and 88% of cases on the CT side, compared to 8%, 32%, 36%, and 16% on the FPT technique side at 2 weeks, 1, 3, and 6 months posttreatment, respectively. The incidence of PIH was significantly lower on the FPT technique side compared to the CT side throughout the follow-up periods. Additionally, transient and mild hypopigmentation occurred in one participant (4%) on the FPT technique side and in five participants (20%) on the CT side. No other adverse effects were observed during the study.

CONCLUSIONS

The 532-nm picosecond laser emerges as a safe and efficacious treatment modality for SL in individuals with FST III-V. Particularly noteworthy is the efficacy of the FPT technique, which demonstrates comparable effectiveness while significantly reducing the incidence of PIH compared to the CT.

Synthetic Polymer Nanoparticles as an Abiotic Artificial Inhibitor of Tyrosinase

An innovative methodology is presented for synthesizing synthetic polymer nanoparticles (TINPs) as potent tyrosinase inhibitors. This inhibition strategy combines the integration of two distinct functionalities, phenol, and phenylboronic acid, within the TINPs structure. The phenyl group mimics the natural monophenol substrate, forming a strong coordination with the catalytic copper ion, significantly inhibiting tyrosinase activity. Additionally, phenylboronic acid interacts with catechol, another tyrosinase substrate, further reducing enzyme efficiency. The shared benzene ring in phenyl and phenylboronic acid enhances binding to tyrosinase's hydrophobic pocket near its copper active site, contributing to potent inhibition. TINPs exhibit exceptional performance, boasting an impressive IC50 value of 3.5×10-8 m and an inhibition constant of 9.8×10-9 m. Validation of the approach is unequivocally demonstrated through the successful inhibition of tyrosinase activity and melanin production, substantiated in both in vitro and in vivo scenarios. The mechanism of TINP inhibition is elucidated through circular dichroism and Fourier transform infrared spectroscopy. This study introduces a versatile design approach for developing abiotic polymer-based enzyme inhibitors, expanding possibilities in enzyme inhibition research.

Outcomes of 1064-nm picosecond laser alone and in combination with fractional 1064-nm picosecond laser in tattoo removal

BACKGROUND

Removal of the unwanted tattoo was initially focused treatment of picosecond laser in the setting of the unfractionated beam, whereas the fractionated 1064-nm picosecond lasers (Fr-Pico) has been successfully utilized in various skin conditions, including scar and benign pigmented lesions. However, no studies compare the combination of Fr-Pico and unfractional 1064-nm picosecond laser (UFr-Pico) and UFr-Pico alone in tattoo removal.

OBJECTIVE

This study aims to compare the efficacy and safety of the combination of Fr-Pico and UFr-Pico and the UFr-Pico and in tattoo removal.

MATERIALS AND METHODS

Nineteen black tattoos in 11 patients were treated with UFr-Pico on one half and in combination with Fr-Pico on another half over three sessions with 4-week intervals and 4-week follow-up after the last session. Treatment efficacy was assessed using digital photographs, skin imaging analysis, and patient satisfaction.

RESULTS

After three treatments, tattoo clearance scores revealed that greater than 50% clearance was achieved in 11 (84.6%) tattoos treated with combination side and 9 (69.2%) tattoos with UFr-Pico alone. Significant differences were observed between the groups at 8 and 12 weeks. Skin textural changes also demonstrated significant improvements in the combination side at week 12. Adverse events, such as blistering and textural changes, were fewer in the combination side.

CONCLUSION

The combination of 1064 nm Fr-Pico and UFr-Pico may be more effective and safer in tattoo removal than UFr-Pico alone.

Tranexamic acid versus fractional carbon dioxide laser in post-acne hyperpigmentation

Post-acne hyperpigmentation is a common undesirable sequela of acne vulgaris that causes distress for many patients. This study's objective was to compare the efficacy of both low-power/low-density fractional carbon dioxide (CO₂ ) laser and tranexamic acid (TXA) microinjection on post-acne hyperpigmentation. Twenty-five post-acne hyperpigmentation patients (resistant to regular treatment for more than 6 months) were enrolled in this randomized split-face study. One side of the face was randomly assigned to low-power fractional CO₂ laser every 4 weeks, and the other side was assigned to TXA intradermal-microinjection every 2 weeks for 3 months. Efficacy was evaluated using digital photography, dermoscopy, post-acne hyperpigmentation index (PAHPI), melanin index (MI), and erythema index (EI) at baseline and 4 weeks after the last session. Both fractional CO₂ laser and TXA microinjection treatment sides showed a significant reduction in the PAHPI and MI (p < 0.001). There was statistically significant difference with better percentage of improvement regarding total dermoscopic score on the fractional CO₂ laser side than the TXA microinjections side (p < 0.009). Both fractional CO₂ laser and TXA microinjection are effective and safe treatment options for post-acne hyperpigmentation with potential superiority of fractional CO₂ laser. We also believe that dermoscopy could be helpful tool for assessment of pigmentation depth in patients on treatment by analyzing the color pattern. ClinicalTrials.govID: NCT03765021.

Comparison of Fractional Picosecond 1064-nm Laser and Fractional Carbon Dioxide Laser for Treating Atrophic Acne Scars: A Randomized Split-Face Trial

BACKGROUND

To date, no studies have compared the fractional picosecond 1064-nm laser (FxPico) and fractional carbon dioxide laser (FxCO2) for the treatment of acne scars.

OBJECTIVE

To compare the efficacy and safety between FxPico and FxCO2 for treating facial atrophic acne scars.

MATERIALS AND METHODS

Twenty-five Asian patients with mild to moderate atrophic acne scars underwent single sessions of randomized split-face treatment with FxPico and FxCO2. Clinical efficacy was assessed by photographs, skin imaging analysis, and patient satisfaction. The adverse events were recorded on every visit. Skin biopsies were performed immediately and 3 months after treatment.

RESULTS

The physician improvement scores for skin texture and atrophy significantly increased on the FxPico sides, but no significant difference was observed between FxPico and FxCO2. Skin imaging also showed significant improvement on both sides for scar volume. Postinflammatory hyperpigmentation (PIH) was not reported on FxPico sides, whereas 6 patients (24%) experienced mild PIH on FxCO2 sides. Immediate post-FxPico skin biopsy revealed laser-induced optical breakdown with photoacoustic columns. Collagen and elastic fibers increased at 3 months after both treatments.

CONCLUSION

FxPico was as effective as FxCO2 in treating atrophic acne scars, correlating with evidence of tissue remodeling with more safety profiles.

Efficacy and safety of a novel combined 1060-nm and 635-nm laser device for non-invasive reduction of abdominal and submental fat

The aim of this study was to evaluate the safety and efficacy of combined 1060-nm diode laser and 635-nm low-level laser therapy (LLLT) device for non-invasive reduction of the abdominal and submental fat. Forty-two healthy subjects received single laser treatment on both the abdomen and submental area. Ultrasound images measuring the thickness of abdominal and submental fat were taken at baseline, follow-up at 4, 8, and 12 weeks after treatment. Waist circumference and body weight were also measured at all visits. Adverse events were recorded at all visits. Subjects completed a satisfaction questionnaire at the end of the trial. Twelve weeks after a single treatment with the investigational device, ultrasound images showed statistically significant (P < 0.0001) reductions in abdominal and submental fat by 18.62 and 26.4%, respectively. In addition, significant (P < 0.0001) reduction in waist circumference was observed. Ninety-six percent of subjects rated that they were satisfied. Noted side effects were transient mild to moderate tenderness which subsided within 1 to 3 weeks. No serious treatment-related adverse events were reported. The dual wavelength device combining 1060-nm diode laser with 635-nm LLLT was safe and effective for non-invasive reduction of both abdominal and submental fat.

Dynamic evaluation of an in vivo postinflammatory hyperpigmentation model using reflectance confocal microscopy and spectrophotometry

BACKGROUND

Postinflammatory hyperpigmentation (PIH) reflects a dynamic process from primary injury and cutaneous inflammation to subsequent melanogenesis and hyperpigmentation, of which pathogenesis remains unclear, hindering the development of targeted therapies.

AIMS

To observe the dynamic development of PIH; determine the starting point and peak point of the inflammatory phase and pigmentary phase; and clarify the timing of anti-inflammatory and anti-pigmentary treatment.

METHODS

Thirty healthy volunteers with Fitzpatrick skin types III-IV were enrolled and underwent suction blisters. The noninvasive evaluation of inflammation and hyperpigmentation on suction blister sites were performed via spectrophotometry (CM2600d and SIAscope) and RCM for the following 24 weeks.

RESULTS

We successfully observed suction blister-induced PIH lasting over 24 weeks. The inflammatory phase started soon after the procedure and lasted for 8-12 weeks, manifested by significantly elevated a* values and erythema index detected by spectrophotometry, as well as inflammatory infiltration and angiogenesis shown in RCM images. Meanwhile, melanogenesis was accelerated after week 3 and reached peak on week 8, manifested by significantly accumulated melanin granules and bright pigment rings in different depths under RCM, which was in parallel with elevated melanin index. The darkening skin tone in PIH actually presented a mixture of inflammatory erythema, angiogenesis, and hyperpigmentation. The inflammation and pigmentation phases of PIH were not sequential but partially overlap.

CONCLUSION

The duration of suction blister-induced PIH is more than 24 weeks. The inflammatory phase partially overlaps with the pigmentary phase, and those drugs with anti-inflammatory and anti-pigmentary dual effects are potential choices.

Objective and Long-Term Evaluation of the Efficacy and Safety of a 1064-nm Picosecond Laser With Fractionated Microlens Array for the Treatment of Atrophic Acne Scar in Asians

BACKGROUND AND OBJECTIVE

Fractional 1064-nm picosecond-domain laser has recently been utilized for the treatment of atrophic acne scars and showed promising results. However, data on the safety and efficacy of this procedure in dark-skinned patients are limited. This prospective, self-controlled study was conducted to objectively evaluate the safety and efficacy of a 1064-nm picosecond laser coupled with a microlens array (MLA) for the treatment of atrophic acne scars on Asian skin.

STUDY DESIGN/MATERIALS AND METHODS

Twenty-six subjects of Fitzpatrick skin types (FSTs) III and IV with atrophic acne scars were enrolled. All subjects were treated with a 1064-nm picosecond laser (spot size of 8 mm, fluence of 1.0 J/cm² , a repetition rate of 10 Hz) in combination with the MLA handpiece for an average of three passes, for 6 monthly sessions. Objective (measurement of scar volume using three-dimensional (3D) photography and skin roughness analysis using ultraviolet A-light video camera) and subjective (clinical evaluation by two blinded dermatologists) assessments were obtained at baseline and at 1, 3, and 6 months after the final treatment.

RESULTS

Statistically significant reduction of the scar volume from baseline at 1, 3, and 6 months after the final treatment were observed by 3D photography and ultraviolet A-light video camera. At the 6-month follow-up, 50% (13 of 26) of the subjects were rated as having at least 50% improvement of the scars. The rate of improvement significantly increased from the 1-month follow-up to the 6-month follow-up (P = 0.013). Similarly, at the 6-month follow-up, the scar volume (P = 0.024) and skin roughness (P = 0.001) also significantly improved, in comparison with the baseline. Mild postinflammatory hyperpigmentation (PIH) was observed to develop in approximately 18% of all the treatment sessions. All cases of PIH were temporary and resolved within 4 weeks on average.

CONCLUSIONS

The 1064-nm picosecond laser with MLA is a safe therapeutic alternative for the treatment of atrophic acne scars in dark-skinned individuals. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Additive Effect of a Combination of Artocarpus lakoocha and Glycyrrhiza glabra Extracts on Tyrosinase Inhibition in Melanoma B16 Cells

Artocarpus lakoocha (Al) and Glycyrrhiza glabra (Gg) extracts have been reported to show tyrosinase inhibitory activity and melanin pigment reduction. This is the first study to assess the combination of Al and Gg extracts in enhancing inhibition of tyrosinase and reduction of melanin pigments. Al and Gg extracted by maceration in 70% and 95% ethanol were analyzed for oxyresveratrol and glabridin using Ultra High Performance Liquid Chromatography. Extracts of Al and Gg singly and combinations of Al95 and Gg95 were tested for cytotoxicity, tyrosinase inhibitory activity, and reduction of melanin pigments in melanoma B16 cells. Al95 had higher antioxidant, tyrosinase inhibitory activity and reduced more melanin pigments in B16 cells compared to Al70, and exhibited higher levels of oxyresveratrol. Gg95 inhibited oxidative stress and mushroom tyrosinase better than Gg70, and exhibited higher levels of glabridin. Combinations of Al95 and Gg95 at various ratios (concentration of 0.1 mg/mL) were not cytotoxic to B16 cells. Interestingly, Al95 and Gg95 combined at a ratio 9:1 reduced melanin pigment up to 53% in B16 cells. This combination of Al95 and Gg95 extracts exhibited the additive effect of reducing melanin pigments by suppressing the expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR) and tyrosinase-related protein-2 (TRP-2) in B16 cells. The combination of Al and Gg extracts could be developed as skin care products for hyperpigmentation treatment.

Fusidic acid cream comparatively minimizes signs of inflammation and postinflammatory hyperpigmentation after ablative fractional CO2 laser resurfacing in Chinese patients: A randomized controlled trial

BACKGROUND

Inflammation and postinflammatory hyperpigmentation (PIH) are two adverse side effects of ablative fractional CO₂ laser (ablative Fr CO₂ ) treatment for both rejuvenation and acne scars.

AIMS

To evaluate the efficacy of fusidic acid cream versus erythromycin ointment as postoperative therapy in patients who underwent ablative Fr CO₂ treatment for atrophic acne scars.

METHODS

Sixty Chinese patients who fulfilled the study criteria were recruited and randomly assigned to an experimental group treated with fusidic acid cream or a control group treated with erythromycin ointment. Postoperative treatment lasted for 7 days in each group. Each patient had two follow-up visits at 8 and 12 weeks. In total, three patients dropped out of the study, one in the experimental group at week 8 and two in the control group at weeks 8 and 12. Baseline and postoperative inflammation and PIH were assessed by facial examination, photographs, and questionnaires. Besides, PIH was evaluated by the Hyperpigmentation Activity and Severity Index (HASI) and a five-point grading system.

RESULTS

Moderate-to-severe PIH was observed in both groups. However, the mean HASI score and severity of PIH in the experimental group were lower than those of the control group at weeks 8 and 12 (P < 0.05). In the control group, one patient developed postoperative abscesses and one had papules, whereas no inflammation was observed in the experimental group participants.

CONCLUSION

Fusidic acid cream shows promise as a common treatment after ablative Fr CO₂ therapy to reduce postoperative inflammation and PIH.

Efficacy of a wound-dressing biomaterial on prevention of postinflammatory hyperpigmentation after suction blister epidermal grafting in stable vitiligo patients: a controlled assessor-blinded clinical study with in vitro bioactivity investigation

Postinflammatory hyperpigmentation (PIH) is a common disfiguring complication following inflammatory dermatoses and cosmetic procedures in dark-skinned individuals. Anti-inflammatory and repairing agents targeting primary inflammation and injury are becoming promising choices for preventing PIH. The aim of this active-controlled, assessor-blinded, intra-individual monocentric study was to evaluate the preventive effect of a wound-dressing biomaterial, mussel adhesive protein (MAP) in the suction blister-induced PIH model. Twenty Chinese patients underwent suction blister epidermal grafting had defined wound areas to receive a topical MAP spray or a potent corticosteroid cream once daily for seven consecutive days after operation. In situ semi-quantitative evaluations of inflammation and pigmentation were achieved by Mexameter, reflectance confocal microscopy and dermoscopy on week 1, week 4, and week 12. Topical application of MAP exerted remarkably inhibitory effect on PIH comparable to fluticasone propionate, manifested as significantly lower melanin index and papillary contrast measured by Mexameter and confocal microscopy on week 12 compared to untreated sites. Although MAP exhibited moderate anti-inflammatory effect weaker than fluticasone propionate, MAP-treated sites healed faster than steroid-treated and untreated sites. The biological activity of MAP was further studied in UVB-irradiated HaCaT cell model, which revealed MAP decreased the expression of UVB-induced α-melanocyte stimulating hormone (α-MSH) and pro-inflammatory cytokines (IL-1α, IL-6, COX-2). It also protected HaCaT cells from UVB-induced cell death and apoptosis. In conclusion, MAP could be a novel postoperational wound dressing preventing PIH associated with skin inflammation and injury.

The Role of Sunscreen in Melasma and Postinflammatory Hyperpigmentation

Photosensitive conditions such as melasma and postinflammatory hyperpigmentation (PIH) are exacerbated by exposure to ultraviolet (UV) rays and visible light making sunscreen use an essential component of treatment. This is especially true in skin of color patients who are less likely to use photoprotection, even if diagnosed with these photoexacerbated conditions. We aimed to evaluate the body of literature to provide evidence for the use of sunscreen in the treatment of melasma and PIH. We reviewed English articles from PubMed, Journals@Ovid Full Text, and Embase using the search terms “sunscreen” and either “melasma” “PIH,” or “post-inflammatory hyperpigmentation.” Nine relevant publications provide evidence that a broad spectrum of protection, including UVA, UVB, and visible light within sunscreens can play an adjuvant role in therapy for melasma and PIH by stabilizing and improving these pigmentary disorders in skin of color patients. This review illustrates the advantages and limitations of sunscreen use, as well as practice gaps in photoprotection in the skin of color patients with melasma and PIH.

Acne treatment efficacy of intense pulsed light photodynamic therapy with topical licochalcone A, l-carnitine, and decanediol: A spilt-face, double-blind, randomized controlled trial

BACKGROUND

Depending on disease severity, standard acne treatments can vary from topical to systemic therapy. However, poor compliance caused by adverse events and antibiotic resistance is a major cause of treatment failure.

AIMS

To determine the effectiveness of photodynamic therapy (PDT) with intense pulsed light (IPL) in the treatment of acne when combined with a cream containing licochalcone A, L-carnitine and decanediol (so-called, 'active formulation') versus PDT alone.

PATIENTS/METHODS

Twenty-nine volunteers, aged 21-39 years (26 women and 3 men, mean age 29.41 ± 5.24 years), with mild to severe facial acne, were enrolled. Each subject's face sides were randomized in a split-face manner to either receive PDT (IPL with a 400-720 nm cut-off filter, at 4 sessions with two-week intervals) combined with the active formulation cream twice daily for 10 weeks on one face side; or PDT and the vehicle cream on the other side, with the same treatment protocol. Reduction in acne quantity, melanin index and erythema index were assessed 2 weeks after the second treatment (day 28), 1 week after the fourth treatment (day 49), and 1 month after the fourth treatment (day 70).

RESULTS

Compared to baseline, patients in the active formulation group demonstrated a faster onset of reduction in the number of lesions at 2 weeks after the second treatment (p=0.010 for inflammatory acne and p=0.001 for non-inflammatory acne). A significantly greater reduction in lesion count was observed in the active formulation group compared with the vehicle group at all timepoints of evaluation for noninflammatory acne (day 28, day 49, and day 70; p=0.003, 0.005 and 0.002 respectively), and at 1 month after the fourth treatment for inflammatory acne (p=0.036). Compared to the vehicle group, the melanin index of the active formulation group decreased significantly at 1 month after the fourth treatment (p=0.015).

CONCLUSION

PDT is more effective in treating acne when combined with a topical cream containing licochalcone A, L-carnitine and decanediol, than PDT alone. Significant acne reduction and improvements in post-inflammatory hyperpigmentation were observed, which offers acne patients a better therapeutic option. It is a safe and effective combination treatment for patients with moderate and severe acne.

Skin whitening agents: medicinal chemistry perspective of tyrosinase inhibitors

Melanogenesis is a process to synthesize melanin, which is a primary responsible for the pigmentation of human skin, eye and hair. Although numerous enzymatic catalyzed and chemical reactions are involved in melanogenesis process, the enzymes such as tyrosinase and tyrosinase-related protein-1 (TRP-1) and TRP-2 played a major role in melanin synthesis. Specifically, tyrosinase is a key enzyme, which catalyzes a rate-limiting step of the melanin synthesis, and the downregulation of tyrosinase is the most prominent approach for the development of melanogenesis inhibitors. Therefore, numerous inhibitors that target tyrosinase have been developed in recent years. The review focuses on the recent discovery of tyrosinase inhibitors that are directly involved in the inhibition of tyrosinase catalytic activity and functionality from all sources, including laboratory synthetic methods, natural products, virtual screening and structure-based molecular docking studies.

Postinflammatory hyperpigmentation: A comprehensive overview: Treatment options and prevention

Postinflammatory hyperpigmentation (PIH) occurs after various dermatoses, exogenous stimuli, and dermatologic procedures. The clinical course of PIH is chronic and unpredictable, although the probability of resolution of epidermal hyperpigmentation is better than those of dermal hyperpigmentation. PIH can be prevented or alleviated. When it does occur, the underlying inflammatory conditions should be sought and treated as the first step to reduce the progression of inflammation and PIH (which is an inflammatory consequence). If the inflammatory conditions subsides or there is no evidence of inflammation at the time of diagnosis, the treatments of PIH should be considered as the next step. Understanding the available treatment options helps the physician choose the appropriate treatment for each patient. Having a reproducible model for PIH is essential for the development of treatment modalities. The second article in this 2-part continuing medical education series on PIH specifically addresses the evidence that supports medical and procedural treatments of PIH and other forms of acquired hyperpigmentation. It also describes a PIH model and provides an algorithm for clinical practice along with discussion about the prevention of PIH.

[Optimization of the healing process after laser procedure, except photorejuvenation]

The use of Lasers in dermatology implies a crucial follow-up in order to optimize the final result and avoid any side effects. With the use of ablative laser devices, the initial phase is characterized by the development of crusts. These crusts necessitate the application of sterile ointments (regularly repeated throughout the day) as well as an antibiotic ointment two times a day. In a second step, comes a secondary inflammatory state, in the dermis, which is generally observed at the outset of all other laser treatments. The main purpose is to avoid it from being too sustained over time, but also to prevent the occurrence of post inflammatory hyperpigmentation. Obviously, a solar eviction will be strongly recommended. The risk being maximized with dark phototypes, the choice of the Laser, as well as its specific parameters will be specific and decisive.

Postinflammatory hyperpigmentation associated with treatment of solar lentigines using a Q-Switched 532-nm Nd: YAG laser: a multicenter survey

PURPOSE

To characterize the risk factors of Korean patients for postinflammatory hyperpigmentation (PIH) during treatment of solar lentigines using a Q-switched 532-nm Nd: YAG (QS 532 NY) laser.

MATERIALS AND METHODS

The present retrospective multicenter study was conducted at the dermatology clinics of five tertiary hospitals in Korea. Between October 2007 and January 2013, 516 patients were enrolled and reviewed for clinical features and factors associated with PIH.

RESULTS

The overall incidence of PIH was 20.3%. We demonstrated that patients with erythematous lentigines presented with PIH more frequently compared with those without erythematous lentigines. Among several coexisting conditions, facial diffuse dyschromia was significantly associated with PIH. Furthermore, PIH occurred more frequently in patients with invisible pores and velvety skin. However, age, sex, Fitzpatrick skin's phototype and season of treatment showed little association with PIH.

CONCLUSIONS

When a QS 532 NY laser is used to treat individuals with erythematous lentigines, invisible pores and velvety skin, and facial diffuse dyschromia, clinicians should be cautious and consider preventive measures.

Adjuvant alternative treatment with chemical peeling and subsequent iontophoresis for postinflammatory hyperpigmentation, erosion with inflamed red papules and non-inflamed atrophic scars in acne vulgaris

The standard management of acne vulgaris in Japan includes a combination of topical treatment with benzoyl peroxide (BPO) and BPO/clindamycin (CLDM), topical adapalene and systemic antimicrobials. However, the treatment of therapy-resistant complications such as postinflammatory hyperpigmentation (PIH), erosions with inflamed red papules and atrophic scars has not been established. We performed chemical peeling with glycolic acid and iontophoresis with ascorbyl 2-phosphate 6-palmitate and DL-α-tocopherol phosphate for the treatment of PIH, erosions with inflamed red papules and non-inflamed atrophic scars in 31 patients with acne vulgaris (mild to severe severity), and evaluated the efficacy and safety of these interventions. In most of cases, there was remarkable improvement in PIH and erosions with inflamed red papules after treatment. There was also some improvement in non-inflamed atrophic scars without erythema. Mild redness and irritation was observed in four cases as adverse reactions. Early initial treatment of PIH and erosions with red papules by chemical peeling and iontophoresis is an effective and safe method to prevent the formation of atrophic scars in patients with acne vulgaris.

Skin Hyperpigmentation in Indian Population: Insights and Best Practice

Skin pigmentation is one of the most strikingly variable phenotypes in humans, therefore making cutaneous pigmentation disorders frequent symptoms manifesting in a multitude of forms. The most common among them include lentigines, postinflammatory hyperpigmentation, dark eye circles, and melasma. Variability of skin tones throughout the world is well-documented, some skin tones being reported as more susceptible to pigmentation disorders than others, especially in Asia and India. Furthermore, exposure to ultraviolet radiation is known to trigger or exacerbate pigmentation disorders. Preventive strategies for photoprotection and treatment modalities including topical and other medical approaches have been adopted by dermatologists to mitigate these disorders. This review article outlines the current knowledge on pigmentation disorders including pathophysiology, molecular profiling, and therapeutic options with a special focus on the Indian population.

Recent progress in melasma pathogenesis

Melasma is a common skin pigmentation condition. Given therapeutic difficulty as one of the biggest concerns, understanding of the etiology and pathogenesis of melasma becomes essential. UV irradiation, female sex hormones, and inflammatory processes are addressed as triggering factors with genetic predisposition. The mechanism of UV-induced melanogenesis has been extensively investigated as a model system to study melasma pathogenesis. Hitherto, treatment modalities for melasma are similar to other hyperpigmentation disorders. However, individual triggering factors induce a separate pigmentation disease, whose pathogenic mechanisms and clinical phenotypes are different from the ones encountered in melasma. Fortunately, there have been ongoing updates on melasma pathogenesis with regard to major triggering factors. Presence of certain factors working independently of UV exposure and role of dermal factors and microRNAs are being identified as novel discoveries about melasma pathogenesis. In this review, the melasma pathogenesis is reviewed in association with updated and new findings.

In vivo time-sequential histological study focused on melanocytes: suggestion of golden time for intervention to prevent post-laser pigmentary changes

BACKGROUND

Post-inflammatory pigmentary changes after laser treatments are challenging adverse effect.

OBJECTIVE

To suggest an ideal time period with regard to intervention to prevent post-laser pigmentary changes, an in vivo time-sequential histological study focused on melanocytes was performed.

METHODS

The back skin of four volunteers was irradiated with Q-switched alexandrite laser (QSAL). In one subject (subject 4), topical corticosteroid was applied onto the irradiated skin from the time of irradiation to day 28. In all subjects, time-sequential skin biopsies were performed at baseline, an immediate time after irradiation, day 2, day 7, and day 28. Histological and immunohistochemical analyses were conducted.

RESULTS

Q-switched alexandrite laser led to the successful removal of pigments and most melanocytes from the epidermis in all subjects. At day 28, there was increased epidermal pigmentation in the skin of the subjects 1-3. It was noted that numerous activated melanocytes appeared on day 7, continued to be observed until day 28. However, in the subject 4, the melanocyte activation and post-laser pigmentary changes were not observed.

CONCLUSION

In regard to intervene melanocyte activation, at least 1 week after laser treatment is suggested as a 'golden' time period to prevent pigmentary changes.

Fermented broth in tyrosinase- and melanogenesis inhibition

Fermented broth has a long history of applications in the food, pharmaceutical and cosmetic industries. Recently, the use of fermented broth in skin care products is in ascendance. This review investigates the efficacy of fermented broth in inhibiting tyrosinase and melanogenesis. Possible active ingredients and hypopigmentation mechanisms of fermented broth are discussed, and potential applications of fermented broth in the cosmetic industry are also addressed.

Lasers and light-based therapies in ethnic skin: treatment options and recommendations for Fitzpatrick skin types V and VI

Ethnic skin or 'skin of colour', which is characterized by increased epidermal melanin, labile melanocytes and reactive fibroblast responses, poses special challenges for the use of laser and light-based therapies. These therapies are associated with a greater risk of dyspigmentation and scarring in ethnic skin and therefore require careful selection of device and treatment parameters to minimize complications. Whereas early-generation lasers for hair removal and resurfacing were generally contraindicated for individuals with Fitzpatrick skin phototypes (SPT) IV-VI, advances in the past decade have given rise to a range of devices that can be safely used in ethnic skin. Longer wavelength lasers such as the 810 and 1064 nm Nd:YAG; intense pulsed light and monochromatic excimer light (308 nm); fractional lasers; and radiofrequency devices have all been used safely for hair removal, pigmentary abnormalities, resurfacing and skin tightening in ethnic skin, respectively. Notwithstanding these advances, nuances in the laser or light treatment of darker skin types remain and must be considered to ensure safe therapeutic outcomes. The vast majority of published data pertaining to lasers and light treatments in nonwhite skin involve patients of East Asian ethnicity (e.g. Korean, Japanese, Chinese, Thai). By contrast, there is a paucity of studies involving individuals of African ancestry or those with SPT V or VI. This article will review laser and light-based modalities that are considered safe and effective for individuals with richly pigmented skin.

The use of sunscreen starting on the first day after ablative fractional skin resurfacing

BACKGROUND

The most common side-effect of ablative fractional skin resurfacing in Asians is post inflammatory hyperpigmentation (PIH). Various attempts have been made to reduce the occurrence of PIH after laser treatment including sun avoidance, the use of preoperative and postoperative treatment regimens, and treatment using conservative energy settings and epidermal protection.

OBJECTIVES

To determine whether the use of broad-spectrum sunscreen with anti-inflammatory agents starting on the first day after fractional CO2 laser skin resurfacing reduces the incidence of post laser PIH.

MATERIALS AND METHODS

Thirty patients were treated with ablative fractional CO2 resurfacing on both sides of their faces at 10 mJ and 10% density. Each subject was randomly treated on one side of the face with petrolatum ointment four times a day for the first week after laser treatment and on the other side of the face with petrolatum ointment four times a day plus broad-spectrum sunscreen with anti-inflammatory agents in the morning starting on the first day after laser treatment. Transepidermal water loss was recorded at baseline and every day for 1 week. Melanin and erythema indexes were measured at baseline, 1-, 2-week, 1-, 2- and at 3-month post treatment.

RESULTS

Of the 30 patients involved in the study, 26 received the treatment and attended 1-, 2-week, 1-, 2- and 3-month post-treatment visits. Four patients were withdrawn from the study because they could not attend every follow-up visit. There was no statistically significant difference in transepidermal water loss at baseline, immediately after laser treatment, or at the D1 to D7 follow-up visits. Erythema index had no significantly statistical difference at baseline, 1-, 2- and at 3-month after laser treatment. Furthermore, there was a statistically significant difference in melanin index at 1-week post laser treatment between both sides (P = 0.001). Melanin index at the 1-week follow-up visit on the side treated with broad-spectrum sunscreen with anti-inflammatory agents starting on the first day after laser treatment was significantly less than the control side.

CONCLUSION

The use of broad-spectrum sunscreen with anti-inflammatory agents starting on the first day after ablative fractional skin resurfacing can decrease the incidence of PIH after laser treatment at 1-week postoperatively.

Inhibitory effect of Korean Red Ginseng on melanocyte proliferation and its possible implication in GM-CSF mediated signaling

Korean Red Ginseng (KRG) has been reported to exert anticancer, anti-oxidant, and anti-inflammatory effects. However, there has been no report on the effect of KRG on skin pigmentation. In this study, we investigated the inhibitory effect of KRG on melanocyte proliferation. KRG extract (KRGE) at different concentrations had no effect on melanin synthesis in melan-A melanocytes. Saponin of KRG (SKRG) inhibited melanin content to 80% of the control at 100 ppm. Keratinocyte-derived factors induced by UV-irradiation were reported to stimulate melanogenesis, differentiation, proliferation, and dendrite formation. In this study, treatment of melan-A melanocytes with conditioned media from UV-irradiated SP-1 keratinocytes increased melanocyte proliferation. When UV-irradiated SP-1 keratinocytes were treated with KRGE or SKRG, the increase of melanocyte proliferation by the conditioned media was blocked. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was produced and released from UV-irradiated keratinocytes. This factor has been reported to be involved in regulating the proliferation and differentiation of epidermal melanocytes. In this study, GM-CSF was significantly increased in SP-1 keratinocytes by UVB irradiation (30 mJ/cm(2)), and the proliferation of melan-A melanocytes increased significantly by GM-CSF treatment. In addition, the proliferative effect of keratinocyte-conditioned media on melan-A melanocytes was blocked by anti-GM-CSF treatment. KRGE or SKRG treatment decreased the expression of GM-CSF in SP-1 keratinocytes induced by UVB irradiation. These results demonstrate that UV irradiation induced GM-CSF expression in keratinocytes and KRGE or SKRG inhibited its expression. Therefore, KRG could be a good candidate for regulating UV-induced melanocyte proliferation.