Skin Color Analysis of Various Body Parts (Forearm, Upper Arm, Elbow, Knee, and Shin) and Changes with Age in 53 Korean Women, Considering Intrinsic and Extrinsic Factors.

Background/Objectives: Skin color is innately determined by race and other genetic factors, and it also undergoes acquired changes due to various intrinsic and extrinsic factors. Previous studies on skin color have mainly focused on the face, and research has recently expanded to other body parts. However, there is limited information about the age-dependent changes in the skin color of these body parts. The purpose of this study is to analyze the differences in skin color between various body parts and the changes in skin color of each body part with age. Methods: This study examined the skin color of 53 Korean women subjects evenly distributed in age from the 20s to 60s on several body parts: forearm, upper arm, elbow (extended or folded), knee (extended or folded), thigh, and shin. The lightness (L*), redness (a*), and yellowness (b*) were measured using a spectrophotometer, and the individual typology angle (ITA°) was calculated from the L* and b* values. The melanin index and erythema index were measured using the mexameter. Results: The results showed that the elbow skin had the lowest L* and ITA° values and the highest a* and b* values among the examined body parts, followed by the knee. The melanin index and erythema index were also high in the skin of these body parts. In the analysis of age-dependent changes in the skin color of various body parts, the forearm skin exhibited the most notable decrease in the L* and ITA° values and increases in the a* and b* values, followed by upper-arm skin. The melanin and erythema indices in the forearm also increased as the subjects aged, whereas those in the elbow and knee rather decreased with age. Conclusions: This study suggests that differences in intrinsic and extrinsic skin aging in various body parts may be expressed as different changes in skin color and raises the need for cosmetic and dermatological research to identify the physiological significance of these changes.

Clinical application of hempseed or flaxseed oil-based lyotropic liquid crystals: Evaluation of their impact on skin barrier function.

The principal function of skin is to form an effective barrier between the human body and its environment. Impaired barrier function represents a precondition for the development of skin diseases such as atopic dermatitis (AD), which is the most common inflammatory skin disease characterized by skin barrier dysfunction. AD significantly affects patients' quality of life, thus, there is a growing interest in the development of novel delivery systems that would improve therapeutic outcomes. Herein, eight novel lyotropic liquid crystals (LCCs) were investigated for the first time in a double-blind, interventional, before-after, single-group trial with healthy adult subjects and a twice-daily application regimen. LCCs consisted of constituents with skin regenerative properties and exhibited lamellar micro-structure, especially suitable for dermal application. The short- and long-term effects of LCCs on TEWL, SC hydration, erythema index, melanin index, and tolerability were determined and compared with baseline. LCCs with the highest oil content and lecithin/Tween 80 mixture stood out by providing a remarkable 2-fold reduction in TEWL values and showing the most distinctive decrease in skin erythema levels in both the short- and long-term exposure. Therefore, they exhibit great potential for clinical use as novel delivery systems for AD treatment, capable of repairing skin barrier function.

Asiatic acid-entrapped transfersomes for the treatment of hypertrophic scars: In vitro appraisal, bioactivity evaluation, and clinical study.

Non-invasive treatment options for hypertrophic scars (HTS) are limited, and treating HTS remains challenging due to their unappealing appearance and associated social stigma. In this work, a novel transfersomal system named Asiatic acid-entrapped transfersomes (AATs) was prepared. AATs were evaluated for their skin permeability, anti-inflammatory activity, and other characteristic parameters to determine the most promising formulation. Asiatic acid-entrapped transfersomal gel (AATG), which was obtained by incorporating the lead AATs in a gel base, underwent testing in an 8-week, double-blind, placebo-controlled, split-skin clinical study. The net skin elasticity (R5), melanin index (MI), and skin surface hydration were analyzed employing Cutometer®, Mexameter®, and Corneometer®, respectively, in order to evaluate the effectiveness of the developed AATG. AATs exhibited vesicular sizes and zeta potential values within the range of (27.15 ± 0.95 to 63.54 ± 2.51 nm) and (-0.010 to -0.129 mV), respectively. TW80AAT gave the highest %EE (90.84 ± 2.99%), deformability index (101.70 ± 11.59 mgs-1), permeation flux at 8 h (0.146 ± 0.005 mg/cm2/h), and anti-inflammatory activity (71.65 ± 1.83%). The clinical study results of AATG indicated no adverse skin reactions. Furthermore, product efficacy tests demonstrated a significant reduction in MI and an increase in net skin elasticity at 2, 4, and 8 weeks. These pilot study outcomes support the effectiveness of the AATG.

Results of longitudinal Nutri-D study: factors influencing winter and summer vitamin D status in a Caucasian population.

Introduction: Inadequate vitamin D status is a worldwide public health issue. In humans, vitamin D status is affected by diet, and even more by exposure to ultraviolet B (UVB) light and consequential endogenous synthesis. Various personal and environmental factors influence endogenous synthesis. Factors affecting vitamin D status were investigated in a prospective longitudinal cohort study with a summer and winter observation period. Methods: The final sample included 292 adults, of those 111 (38%) males and 181 (62%) females, with a mean age of 38.2 (±11.8) years from Slovenia who were not supplementing vitamin D. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured in both periods; vitamin D intake, self-reported body mass index (BMI), and protective behaviors against sun were also recorded. Other measured parameters included measurements of constitutive skin color using the objective individual typology angle (ITA), and difference in the melanin index (ΔMI) for assessment of objective sun exposure. Results: In winter a high prevalence (63.4%) of insufficient vitamin D status (< 50 nmoL/L) was observed with higher odds ratios (OR) for insufficiency in those with a higher BMI and light ITA. During summer, insufficiency prevalence was low (5.5%), but half of the participants (50.0%) had suboptimal 25(OH)D concentration (< 75 nmol/L). In summer OR for suboptimal status were higher in those with obesity, lower ΔMI, light ITA, low vitamin D intake, and protective clothing behaviors. Conclusion: Using a series of measures, we showed that vitamin D status is hugely affected by several personal factors such as BMI, ITA, vitamin D intake, ΔMI, and protective behavior against the sun. This conclusion questions the usefulness of generalized population-level recommendations since personal factors are a major predictor of vitamin D status.

Generation of skin tone and pigmented region-modified images using a pigment discrimination model trained with an optical approach.

BACKGROUND: Skin tone and pigmented regions, associated with melanin and hemoglobin, are critical indicators of skin condition. While most prior research focuses on pigment analysis, the capability to simulate diverse pigmentation conditions could greatly broaden the range of applications. However, current methodologies have limitations in terms of numerical control and versatility. METHODS: We introduce a hybrid technique that integrates optical methods with deep learning to produce skin tone and pigmented region-modified images with numerical control. The pigment discrimination model produces melanin, hemoglobin, and shading maps from skin images. The outputs are reconstructed into skin images using a forward problem-solving approach, with model training aimed at minimizing the discrepancy between the reconstructed and input images. By adjusting the melanin and hemoglobin maps, we create pigment-modified images, allowing precise control over changes in melanin and hemoglobin levels. Changes in pigmentation are quantified using the individual typology angle (ITA) for skin tone and melanin and erythema indices for pigmented regions, validating the intended modifications. RESULTS: The pigment discrimination model achieved correlation coefficients with clinical equipment of 0.915 for melanin and 0.931 for hemoglobin. The alterations in the melanin and hemoglobin maps exhibit a proportional correlation with the ITA and pigment indices in both quantitative and qualitative assessments. Additionally, regions overlaying melanin and hemoglobin are demonstrated to verify independent adjustments. CONCLUSION: The proposed method offers an approach to generate modified images of skin tone and pigmented regions. Potential applications include visualizing alterations for clinical assessments, simulating the effects of skincare products, and generating datasets for deep learning.

A Cross-Sectional Assessment of Quantitative Epidermal Melanin and Erythema Indices among North Indians.

Background: Remarkable diversity of skin tones among Indians ranging from pale pinkish to dark brown appears to be an ideal choice for the assessment of skin pigment variation. Aim: The present study was designed to assess the variation observed in melanin and erythema indices among north Indians. Material and Methods: Skin reflectance data (n = 574) was collected from six diverse populations of north India using DermaSpectrometer (DSM II ColorMeter) followed by statistical analysis to investigate the impact of geographical location and gender on constitutive skin pigmentation. Results: The melanin index (MI) varied between 17.93 and 56.92 (Mean (M) = 35.80 ± 6.26) whereas the erythema index (EI) varied between 4.92 and 18.82 (M = 10.48 ± 2.68). MI and EI of females were found to be significantly lower than males (P < 0.001). Geographical location exhibited a significant association with MI and EI (P < 0.001). Furthermore, we have noted a positive correlation between MI and EI (P < 0.001). Conclusion: The study has refined our understanding of skin pigmentation variation among north Indians in terms of significant association with geographical location {MI: F (5,568) = 31.07, P < 0.001; EI: F (5,568) = 73.37, P < 0.001} and gender {MI: t (386) = -4.06, P < 0.001; EI: t (386) = -11.96, P < 0.001} and rendered opportunities for further studies.

The effect of low-intensity cold atmospheric plasma jet on photoaging-induced hyperpigmentation in mouse model.

BACKGROUND: Cold atmospheric plasma (CAP) produces reactive oxygen/nitrogen species (RONS) in the target and can induce cytoprotective effects by activating hormesis-related pathways when its intensity is in the low range. OBJECTIVES: The aim of this study is to evaluate the effect of low-intensified CAP (LICAP) on skin with photoaging-induced hyperpigmentation in an animal model. METHODS: Changes in cell viability and RONS production following LICAP treatment were measured. For the in vivo study, 30 hairless mice underwent antecedent photoaging induction followed by the allocated therapy (i.e., LICAP, topical ascorbic acid (AA), or both). During the first 4 weeks of the treatment period (8 weeks), ultraviolet (UV)-B irradiation was concurrently administered. Visual inspection and measurement of the melanin index (MI) were performed to assess the change in skin pigmentation at Weeks 0, 2, 4, 6, and 8. RESULTS: RONS production increased linearly until the saturation point. Cell viability was not significantly affected by LICAP treatment. At Week 8, MI was significantly decreased in every treatment group compared with the values at Week 0 and Week 4. The treatment effect of the concurrent therapy group was superior to that of the LICAP and AA groups. CONCLUSION: LICAP appears to be a novel modality for photoprotection and pigment reduction in photodamaged skin. LICAP treatment and topical AA application seem to exert a synergistic effect.

A randomized comparative study of the effect of two different flow rates of carboxytherapy in the treatment of infraorbital dark circles.

BACKGROUND: Carboxytherapy is a minimally invasive, relatively safe modality that has been used for the treatment of dark circles; however, different flow rates and different injection techniques have been described in the literature. AIM: To study the effect of the flow rate on the therapeutic outcome of carboxytherapy in infraorbital dark circles. METHODS: Eighty patients with infraorbital dark circles were divided into two equal groups: Group A received carboxytherapy at a flow rate of 30 ml/min, and group B received carboxytherapy at a flow rate of 60 ml/min. Patients received weekly sessions for 6 weeks, and the treatment response was evaluated 6 weeks after the last treatment session. RESULTS: Significant improvement of the dark circles was detected in both treatment groups. However, no significant difference in the treatment response was found when both flow rates were compared. The frequency of development of side effects was significantly higher in the group receiving CO2 at a flow rate of 60 ml/min. No significant difference in the overall post-treatment patient satisfaction between the two groups was detected. CONCLUSION: Carboxytherapy is an effective therapeutic modality for infraorbital dark circles. Lower flow rates achieve therapeutic responses similar to higher flow rates but with fewer side effects.

Clinical brightening efficacy and safety of Melasolv™ (3,4,5-trimethoxy cinnamate thymol ester, TCTE) in Southeast Asian women.

BACKGROUND: Skin darkening because of increased and irregular synthesis of melanin causes melasma, solar lentigo, and freckles. Melasolv™, produced in the early 2000s, shows potent depigmenting effect and has low cytotoxicity. It has been used as a brightening agent in cosmetics for decades. AIMS: This study was conducted to investigate whether Melasolv™ is effective for the skin of ASEAN (Southeast Asia) women. METHODS: We recruited ASEAN women in Singapore and divided them into two groups (active group vs. placebo group). Melasolv™ and placebo formulations were applied twice a day for 12 weeks. The changes in the pigmented spots were visually evaluated by an expert and assessed using a spectrophotometer and Mexameter at 0, 4, 8, and 12 weeks. RESULTS: The visual evaluation revealed significant improvements, in both size and color intensity, in the active group compared with those in the placebo group at 12 weeks. In the spectrophotometric evaluation, the L* value of the pigmented spots in the active group was significantly higher than that in the placebo group at 12 weeks. Similar results were obtained in the evaluation using the Mexameter. After 12 weeks, the melanin index of the pigmented spots significantly decreased, and it was significantly higher than that in the placebo group. There was no significant change in the erythema index. In the image analysis, there were no significant differences in skin color brightness and evenness in the active group compared with those in the placebo group. CONCLUSION: Melasolv™ can be effective used for skin brightening.

Subjective and objective skin colour of a farmworker group in the Limpopo Province, South Africa.

BACKGROUND: Farmworkers in the Limpopo Province, South Africa, are at risk of excessive exposure to solar ultraviolet radiation (sUVR) due to both their work and the sUVR environment in the geographic area. However, the natural protection provided by this group's skin against sUVR has not been quantified. The aim of this study was to evaluate the subjective and objective skin colour of a group of farmworkers in order to classify the natural photoprotection provided by melanin and to evaluate the different measurement methods. MATERIALS AND METHODS: Skin colour was established by using the subjective Fitzpatrick skin phototype system (FST) questionnaire and two objective methods, namely the individual typology angle (ITA°) and melanin index (MI). A total of 71 farmworkers participated in the study. RESULTS: Black Africans tended to perceive their skin to be lighter than objectively measured, potentially due to cultural factors. The constitutive skin colour of most farmworkers was objectively classified in the FST V/brown group. Significant differences were found between the ITA° and MI of sun-exposed (constitutive) and non-sun-exposed (facultative) skin in Black African and White farmworkers. A strong correlation was found between ITA° and MI on different anatomical positions indicating both methods are appropriate to determine skin colour in deeply pigmented skin. CONCLUSION: The evaluation of skin colour with the use of both subjective and objective methods may be used to design an effective photoprotection programme for farmworkers in the Limpopo Province.

Clinical evaluation method for blue light (456 nm) protection of skin.

BACKGROUND: Blue light from electronic devices enriched with a peak at 456 nm affects circadian rhythm and antioxidant balance of skin, necessitating the study of photoprotection against the 456-nm blue light. AIMS: This study aims to report that blue light (456 nm) can cause skin pigmentation and proposes a new clinical evaluation method for blue light (456 nm) protection based on the skin pigmentation level. PATIENTS/METHODS: We developed a clinical device (ABC deviceTM ) that emits blue light (peak = 456 nm). Based on the minimal persistent pigment darkening dose (MPPD) determined from visual evaluation and melanin index measurements, we proposed the "protection grade of blue light (PB)" guideline to assess the protective ability of skin against blue light. RESULTS: Human skin irradiated with blue light (456 nm) showed a light dose-dependent degree of pigmentation. The MPPD on unprotected and protected skin was 135 J/cm2 or 180 J/cm2 and 135-225 J/cm2 , respectively. The ABC device™ and the proposed clinical method were used to test the four blue light blocking assessments of TiO2 . Consequently, the inorganic filter with TiO2 effectively blocked the blue light (456 nm). The AP product demonstrated the ability to block blue light by 1.15 times (PB = 1.15), which significantly lowered the melanin index of the skin after irradiation as compared to that of the unprotected skin (P < .001). CONCLUSION: We propose an objective clinical evaluation method for blue light protection. This study elucidates the properties of blue light blockers for customers suffering from blue light pollution.

The correlation between severity of melasma with facial wrinkles in Yogyakarta, Indonesia.

Melasma is a common disfiguring condition involving acquired hyperpigmentation especially on the face, for which the pathogenesis is still uncertain, however histopathological studies showed that there is not only hyperpigmentation in the epidermis, but also solar elastosis or photo-aging due to abnormality of dermal extracellular matrix which contributes to clinical wrinkles. This study aimed to examine a link between the severity of melasma and facial wrinkles as a manifestation of photoaging in a tropical area. This study was an observational study with crosssectional design, conducted in Yogyakarta, Indonesia involving 51 patients with melasma aged 30-50 years who had fulfilled the inclusion and exclusion criteria. The melasma severity was measured clinically with the modified Melasma Severity Index (mMASI), and objectively with the Melanin Index (MI) and Erythema Index (EI) assessed with Mexameter Courage Khazaka. The wrinkle severity was measured clinically by scoring from forehead horizontal lines, crow's feet, glabellar and nasolabial lines, and total scores were obtained from all of them. The correlation analysis was done statistically with Spearman's rank tests. The results showed a weak positive but not significant correlation between the mMASI score and total facial wrinkle score (r: 0.165), and a weak positive non-significant correlation between EI and total facial wrinkle score (r: 0.06). There were significant positive moderate correlations between MI and total facial wrinkle score (r: 0.441), due to significant positive moderate correlations between MI and glabella wrinkle (r: 0.392), and between MI and nasolabial wrinkle (r: 0.339). In conclusion, a positive moderate correlation was found between MI and total facial wrinkle score, especially relating to glabellar and nasolabial wrinkles. However, there was no correlation between mMASI score and total facial wrinkle score.

Efficacy of liposome-encapsulated 4-n-butylresorcinol and resveratrol cream in the treatment of melasma.

BACKGROUNDS: We previously reported the efficacy of 0.1% 4-n-butylresorcinol (4nBR) cream in the treatment melasma and synergistic effect of 4nBR and resveratrol (RSV) to inhibit melanogenesis in vitro. AIMS: To evaluate efficacy and safety of a cream which contains liposome-encapsulated 4nBR and RSV in the treatment of melasma. PATIENTS/METHODS: A total of 21 female patients with melasma were treated with the cream for 4 weeks. At baseline, week 2, and week 4, melanin index (MI) of the lesional and preauricular nonlesional skin was measured and two blinded, independent dermatologists assessed the overall severity by 5-point scale. RESULTS: The lesional MI was significantly decreased at weeks 2 and 4 compared with the baseline while no significant change in the nonlesional MI was observed throughout the study. The mean investigator's global assessment score was also significantly improved at weeks 2 and 4. In patient's self-assessment, 8 (38.1%) and 11 (52.3%) patients answered moderate to significant improvement in their melasma at weeks 2 and 4, respectively. No serious adverse events were reported. CONCLUSION: The cream containing liposome-encapsulated 4nBR and RSV was shown to be effective and safe for the treatment of melasma with its effect appearing as early as 2 weeks.

Low-fluence Q-switched Nd:YAG 1064-nm laser versus Q-switched Nd:YAG 532-nm laser in the treatment of hyperpigmented lips: a prospective, randomized, controlled, evaluator-blinded trial.

Lip hyperpigmentation is an esthetic problem. Clinical data from controlled comparative studies is insufficient to support the efficacy of laser treatments for hyperpigmented lips. This study is aimed to compare the efficacy of low-fluence Q-switched Nd:YAG 1064-nm laser (LFQS 1064-nm) versus Q-switched Nd:YAG 532-nm laser (QS 532-nm) for the treatment of hyperpigmented lips. A randomized, controlled, evaluator-blinded study was conducted in thirty subjects. They were randomized into 2 groups. The first group was treated with five treatment sessions with a 2-week interval of LFQS 1064-nm laser while the second group was treated with a single session of QS 532-nm laser. The evaluation was conducted at baseline, 2 weeks of each post treatment, and 4 weeks after the last treatment session. The efficacy was assessed by melanin index, Methuen colored plate, photographic evaluation, pain score, patient's satisfaction, and patient's Dermatology Life Quality Index. The adverse effects were also recorded. All patients attained throughout the study protocol. The most frequent fluence applied was 2.4 J/cm2 (2.2-2.5 J/cm2) and 2.0 J/cm2 (1.7-2.4 J/cm2) in the LFQS 1064-nm group and QS 532-nm group, respectively. The results of the QS 532-nm group showed greater percentage of melanin index reduction and better average mean of photographic evaluation percentage changes from the baseline than the LFQS 1064-nm group (p < 0.001 and p < 0.001, respectively). The adverse effects were less likely to occur in the LFQS 1064-nm group. Few cases of scale, hypopigmentation, bleb formation, postinflammatory hyperpigmentation, and labial edema occurred only in the QS 532-nm group.

Multidiameter single-fiber reflectance spectroscopy of heavily pigmented skin: modeling the inhomogeneous distribution of melanin.

When analyzing multidiameter single-fiber reflectance (MDSFR) spectra, the inhomogeneous distribution of melanin pigments in skin tissue is usually not accounted for. Especially in heavily pigmented skins, this can result in bad fits and biased estimation of tissue optical properties. A model is introduced to account for the inhomogeneous distribution of melanin pigments in skin tissue. In vivo visible MDSFR measurements were performed on heavily pigmented skin of type IV to VI. Skin tissue optical properties and related physiological properties were extracted from the measured spectra using the introduced model. The absorption of melanin pigments described by the introduced model demonstrates a good correlation with the co-localized measurement of the well-known melanin index.

Relationship between skin melanin index and nicotine pharmacokinetics in African American smokers.

BACKGROUND: Blacks bear a disproportionate burden of smoking-related diseases and experience greater difficulty quitting smoking than Whites. Nicotine has a high affinity for melanin, and it has been hypothesized that melanin levels might influence nicotine pharmacokinetics and enhance dependence. The aim of this study was to evaluate the hypothesis that melanin affects nicotine disposition kinetics in humans. METHODS: Forty-four Black participants were administered intravenous infusions of deuterium-labeled nicotine and cotinine. Plasma concentrations of nicotine and cotinine were measured, and pharmacokinetic parameters were estimated. The constitutive and facultative melanin indexes were measured using a dermaspectrophotometer. RESULTS: The median constitutive melanin index was 60.7 (32.8-134.7) and the median facultative melanin index 68.1 (38.6-127.1). The mean (±SD) nicotine elimination half-life was 136 min (±33.5), clearance was 1237 mL/min (±331), and Vss was 204 L (±66), or 2.6 L/kg (±0.7). No evidence of significant differences was found in nicotine pharmacokinetic parameters by comparing participants in different melanin index quartiles (outliers with very high melanin index had similar pharmacokinetic values to others). Differences were not statistically significant when adjusted for age, BMI, sex and CYP2A6 genotype or the nicotine metabolite ratio (NMR), and no evidence of significant correlations were found between melanin (facultative or constitutive) and the pharmacokinetic parameters of nicotine or cotinine or tobacco dependence measures. CONCLUSIONS: Based on our finding in this group of Black smokers, we could not confirm the hypothesis that melanin significantly affects nicotine disposition kinetics or measures of tobacco dependence.

A cream of herbal mixture to improve melasma.

BACKGROUND: Melasma is an acquired, common hyperpigmented disorder on the face. While many therapeutic approaches are available, their efficacy is moderate. OBJECTIVE: To investigate the safety and efficacy of a cream containing herbal mixture for melasma. METHODS: A total of 90 volunteers with melasma were enrolled in this randomized, double-blind, controlled clinical study, and they were randomly divided into three groups (A, B, and C). Patients in group A were treated with a cream containing herbal mixture, while groups B and C were treated with arbutin cream and placebo, respectively, twice daily for 12 weeks. Melasma area and severity index (MASI) score, melanin index (MI), erythema index (EI), changes in density of inflammatory cells, and adverse events were evaluated every 4 weeks. RESULTS: Although MASI scores declined significantly in both groups A and B (P < 0.05), a greater reduction was seen in group A (13.00-9.82 = 3.18 for group A; 12.65-10.84 = 1.81 for group B). Moreover, the cream containing herbal mixture, but not arbutin cream and placebo, significantly reduced EI and density of inflammatory cells after 12-week treatment (P < 0.05). No adverse reactions were observed in either group A or group C. In group B, two subjects experienced mild erythema and itching, which disappeared after stop using the arbutin cream. CONCLUSION: The cream containing herbal mixture is safe and effective for melasma.

Evaluation of different factors influencing objective measurement of skin color by colorimetry.

BACKGROUND: Objective determination of skin color has become an essential requirement in managing pigmentary disorders including vitiligo. The readings of available devices can be influenced by factors such as surrounding temperature, vasodilation/constriction, and skin surface properties. Our aim was to investigate the influence of hair color and length, skin stretching, incomplete contact of the device with the skin, and the pressure with which the device is applied to the test area on skin color determination. MATERIALS AND METHODS: Dermacatch® was used to determine the influence of hair color and length in 30 vitiligo patients, and of wrinkles, incomplete contact of the device with the skin and pressure of the device on the test area in 30 healthy volunteers on melanin and erythema indices measured by the device. RESULTS: Melanin index was significantly higher in lesions with black hair compared to lesions with white hair (P < 0.001) and the MI significantly decreased when the black hair was shaved (P < 0.001) and when the skin over the test area was stretched (P < 0.001). Incomplete contact of the device with the test area led to significantly higher MI (P < 0.001) and lower EI (P < 0.001). Meanwhile, high pressure induced by the device on the test area led to significantly lower MI (P < 0.001) and significantly higher EI (P < 0.001). CONCLUSIONS: Factors influencing the readings of devices used for objective determination of skin color have to be taken consideration to ensure accuracy of the measurements done.

Whitening effect of L-ascorbate-2-phosphate trisodium salt on solar lentigos.

Little is known about the anti-pigmenting effects of whitening agents on solar lentigos (SLs), which comprise ~ 60% of hyperpigmented facial lesions of Asian subjects. Lotions with or without 6% L-ascorbate-2-phosphate trisodium salt (APS) [test lotion (TL) and placebo lotion (PL), respectively] were applied twice daily for 24 weeks in a double-blind half-face study of 27 Japanese females with SLs on both sides of their faces. Pigmentation scores were evaluated using a photo-scale and the skin colors were assessed using a color difference meter and a mexameter for SLs and the non-lesional surrounding skin (NLS). Although the pigmentation scores were not significantly different between the TL and PL-treated SLs after 24 weeks, the L values of TL-treated SLs and NLS increased significantly with a significantly higher △L value in SLs than in NLS. In contrast, the L values of PL-treated SLs and NLS remained unchanged after the treatment. The number of subjects with > 2.0 △L was 7 of 27 (TL) and 0 of 27 (PL) in SLs and 3 of 27 (TL) and 0 of 27 (PS) in NLS. In contrast, the melanin index in TL-treated SLs and NLS significantly decreased with a significantly higher △melanin index in SLs than in NLS. Similarly, the melanin index of PL-treated SLs and NLS were significantly decreased with a significantly higher △melanin index in SLs than in NLS. These findings strongly indicate that APS has a weak but significant anti-pigmenting effect on SLs and a significant whitening effect even on normally pigmented healthy skin.

Efficacy and safety of intense pulsed light with a KTP filter for the treatment of solar lentigines.

BACKGROUND: Optical energy-based devices, including intense pulsed light (IPL) and potassium titanyl phosphate (KTP) lasers achieve reduction of pigmented and vascular lesions in a relatively similar number of treatments. This study aimed to evaluate the efficacy and safety of an IPL with a "KTP-like" filter emitting a wavelength of 525-585 nm for the treatment of solar lentigines on the hands and face. METHODS: This was a single center, prospective, open-label clinical trial including 16 healthy Caucasian subjects (15 females, mean age, 55 years; skin types II and III) with hand and facial solar lentigines. Subjects were treated with three IPL treatment sessions with a KTP-like filter conducted at monthly intervals. Follow-up evaluations were performed 1, 3, and 6 months after the last treatment session. Overall pigmentation improvement, pigmentation clearance per lesion, adverse events, and subject tolerability to treatment were evaluated. RESULTS: Significant improvements in facial and hand pigmentation were noted at all follow-up visits (P < 0.0001). One month after the last treatment session, good to excellent outcomes were noted in 74.6% of treated facial areas and 90% of treated hand regions. Although the effect of treatment gradually declined in both treatment regions over the 6-month follow-up period, over 60% of subjects demonstrated good to excellent results at the study end. Clinical effectiveness was further confirmed by the reduction in Melanin Index (MI) following each treatment as compared to baseline. Downtime and complications were minimal. CONCLUSIONS: IPL treatment with a KTP-like filter is a well-tolerated and effective method for reducing facial and hand pigmentation. Lasers Surg. Med. 51:500-508, 2019. © 2019 Wiley Periodicals, Inc.