Assessment of Natural Sunlight Protection Provided by 10 High-SPF Broad-Spectrum Sunscreens and Sun-Protective Fabrics.

In 1978, the FDA Advisory Panel proposed both indoor and natural sunlight SPF testing methods but reverted to indoor testing only in 1993. Today's sunscreen sun protection and broad-spectrum claims are based on mandated clinical tests using solar simulators and in vitro spectrophotometers. This research evaluated the protection of 10 high-SPF (30-110), broad-spectrum sunscreen products, as well as 6 sun-protective fabrics against natural sunlight in Arequipa, Peru. Each of the 17 subjects was exposed to natural sunlight for 1 h and 59 min under clear skies, with temperatures and humidity similar to those in an indoor clinical laboratory. Test sites were photographed 16-24 h later. Four dermatologists evaluated the photographs for erythema and persistent pigment darkening (PPD). Perceptible sun-induced skin injury (sunburn and/or pigmentation) was detected at 97% of the sunscreen-protected scores. The most sun-sensitive subjects obtained the least erythema protection. The higher the SPF was, the higher the erythema protection, but the intensity of PPD was also higher. The 2 sunscreens using only FDA-approved sunscreen filters rated 30 SPF and 45+ SPF performed poorly: Eighty-one percent of the 136 scores were graded 1 minimal erythema dose or higher erythema, achieving, at a maximum, SPF of 5-7 in natural sunlight. Sun-protective fabrics tested provided excellent sun protection. The erythema and PPD observed through the sunscreens in less than 2 h are incongruous with the broad-spectrum, high-SPF sunscreen claims. Reapplying these sunscreens and staying in the sun longer, as stated on the product labels, would have subjected the subjects to even more UV exposure. High-SPF, broad-spectrum sunscreen claims based on indoor solar simulator testing do not agree with the natural sunlight protection test results.

Cosmetic Laser Procedures in Latin Skin

Hispanics/Latinos are one of the fastest growing segments in the skin of color population in the United States. Utilization of lasers especially in people with skin of color requires a thorough understanding of laser physics and laser tissue interactions. In this article, we will outline the different lasers used in our practice based on each chromophore. Pretreatment recommendations as well as management of complications will also be shortly discussed. Our goal is for the readers to grasp the importance of proper device selection, understand the concept of selective photothermolysis, and the various treatment parameters required for optimal safety and efficacy. J Drugs Dermatol. 2019;18(3 Suppl):s127-131.

Prospective, randomized, double-blind assessment of topical bakuchiol and retinol for facial photoageing.

BACKGROUND: Bakuchiol is a phytochemical that has demonstrated cutaneous antiageing effects when applied topically. Early studies have suggested that bakuchiol is a functional analogue of topical retinoids, as both compounds have been shown to induce similar gene expression in the skin and lead to improvement of cutaneous photodamage. No in vivo studies have compared the two compounds for efficacy and side-effects. OBJECTIVES: To compare the clinical efficacy and side-effect profiles of bakuchiol and retinol in improving common signs of cutaneous facial ageing. METHODS: This was a randomized, double-blind, 12-week study in which 44 patients were asked to apply either bakuchiol 0·5% cream twice daily or retinol 0·5% cream daily. A facial photograph and analytical system was used to obtain and analyse high-resolution photographs of patients at 0, 4, 8 and 12 weeks. Patients also completed tolerability assessment questions to review side-effects. During study visits, a board-certified dermatologist, blinded to study group assignments, graded pigmentation and redness. RESULTS: Bakuchiol and retinol both significantly decreased wrinkle surface area and hyperpigmentation, with no statistical difference between the compounds. The retinol users reported more facial skin scaling and stinging. CONCLUSIONS: Our study demonstrates that bakuchiol is comparable with retinol in its ability to improve photoageing and is better tolerated than retinol. Bakuchiol is promising as a more tolerable alternative to retinol.

The influences of genes, the environment, and social factors on the evolution of skin color diversity in India.

OBJECTIVES: Skin color is a highly visible and variable trait across human populations. It is not yet clear how evolutionary forces interact to generate phenotypic diversity. Here, we sought to unravel through an integrative framework the role played by three factors-demography and migration, sexual selection, and natural selection-in driving skin color diversity in India. METHODS: Skin reflectance data were collected from 10 diverse socio-cultural populations along the latitudinal expanse of India, including both sexes. We first looked at how skin color varies within and between these populations. Second, we compared patterns of sexual dimorphism in skin color. Third, we studied the influence of ultraviolet radiation on skin color throughout India. Finally, we attempted to disentangle the interactions between these factors in the context of available genetic data. RESULTS: We found that the relative importance of these forces varied between populations. Social factors and population structure have played a stronger role than natural selection in shaping skin color diversity across India. Phenotypic overprinting resulted from additional genetic mutations overriding the skin lightening effect of variants such as the SLC24A5 rs1426654-A allele in some populations, in the context of the variable influence of sexual selection. Furthermore, specific genotypes are not associated reliably with specific skin color phenotypes. This result has relevance for DNA forensics and ancient DNA research. CONCLUSIONS: India is a crucible of macro- and micro-evolutionary forces, and the complex interactions of physical and social forces are visible in the patterns of skin color seen today in the country.

Disparity in Cutaneous Pigmentary Response to LED vs Halogen Incandescent Visible Light: Results from a Single Center, Investigational Clinical Trial Determining a Minimal Pigmentary Visible Light Dose.

Background: While most of the attention regarding skin pigmentation has focused on the effects of ultraviolet radiation, the cutaneous effects of visible light (400 to 700nm) are rarely reported. OBJECTIVE: The purpose of this study was to investigate the cutaneous pigmentary response to pure visible light irradiation, examine the difference in response to different sources of visible light irradiation, and determine a minimal pigmentary dose of visible light irradiation in melanocompetent subjects with Fitzpatrick skin type III - VI. METHODS: The study was designed as a single arm, non-blinded, split-side dual intervention study in which subjects underwent visible light irradiation using LED and halogen incandescent light sources delivered at a fluence of 0.14 Watts/cm2 with incremental dose progression from 20 J/cm2 to 320 J/cm2. Pigmentation was assessed by clinical examination, cross-polarized digital photography, and analytic colorimetry. RESULTS: Immediate, dose-responsive pigment darkening was seen with LED light exposure in 80% of subjects, beginning at 60 Joules. No pigmentary changes were seen with halogen incandescent light exposure at any dose in any subject. CONCLUSION: This study is the first to report a distinct difference in cutaneous pigmentary response to different sources of visible light, and the first to demonstrate cutaneous pigment darkening from visible LED light exposure. Our findings raise the concern that our increasing daily artificial light surroundings may have clandestine effects on skin biology.

J Drugs Dermatol. 2017;16(11):1105-1110.

Assessment of skin pigmentation by confocal microscopy: Influence of solar exposure and protection habits on cutaneous hyperchromias.

BACKGROUND: Cutaneous hyperchromias are disorders of skin pigmentation involving an increase of melanin production and its irregular accumulation in skin cells. It is known that the use of sunscreens helps to prevent changes in the skin pigmentation pattern, but the structural and morphological alterations that occur in the different types of hyperpigmentations need better elucidation. OBJECTIVE: To assess the influence of solar exposure and protection habits on the pattern of skin pigmentation using reflectance confocal microscopy (RCM). METHODS: Forty volunteers aged 18-39 years with skin hyperpigmentation participated in the study. Skin characterization was performed by imaging techniques and by assessing the habits of solar exposure and protection by applying questionnaires to the volunteers. RCM was used to record sequences of confocal sections at areas of interest and to examine cell shape and brightness in the basal cell layer of the lesion and in normal perilesional skin. Furthermore, high-resolution images were obtained for analysis of the spots. RESULTS: Sunlight influences the number and location of spots as the face of volunteers with higher solar exposure was covered with spots, whereas volunteers with less exposure had fewer spots located in the nose and cheeks region due to greater exposure of these areas to the sun. CONCLUSION: The data showed the importance of sun protection for preventing changes in the pattern of skin pigmentation, and RCM proved to be an important tool for skin characterization.

Mexametric and cutometric assessment of the signs of aging of the skin area around the eyes after the use of non-ablative fractional laser, non-ablative radiofrequency and intense pulsed light.

The assessment of the signs of aging within eyes area in cutometric (skin elasticity) and mexametric (discoloration and severity of erythema) examination after the treatment with: non-ablative fractional laser, non-ablative radiofrequency (RF) and intense light source (IPL). This study included 71 patients, aged 33-63 years (the average age was 45.81) with Fitzpatrick skin type II and III. 24 patients received 5 successive treatment sessions with a 1,410-nm non-ablative fractional laser in two-week intervals, 23 patients received 5 successive treatment sessions with a non-ablative RF in one-week intervals and 24 patients received 5 successive treatment sessions with an IPL in two-week intervals. The treatment was performed for the skin in the eye area. The Cutometer and Mexameter (Courage + Khazaka electronic) reference test was used as an objective method for the assessment of skin properties: elasticity, skin pigmentation and erythema. Measurements of skin elasticity were made in three or four sites within eye area. The results of cutometric measurements for R7 showed the improvement in skin elasticity in case of all treatment methods. The largest statistically significant improvement (p < .0001) was observed in case of laser and RF, during treatment sessions, at sites at upper and lower eyelid. The smallest change in skin elasticity for the laser, RF and IPL - p = .017, p = .003 and p = .001, respectively-was observed in a site within the outer corner of the eye. In all sites of measurements and for all methods, the greatest improvement in skin elasticity was demonstrated between the first and second measurement (after 3rd procedures). The majority of the results of mexametric measurements-MEX (melanin level) and ERYT (the severity of erythema) are statistically insignificant. Fractional, non-ablative laser, non-ablation RF and intense light source can be considered as methods significantly affecting elasticity and to a lesser extent erythema and skin pigmentation around the eyes. Fractional non-ablative laser is a method which, in comparison to other methods, has the greatest impact on skin viscoelasticity. These procedures are well tolerated and are associated with a low risk of side effects.

Simulating light transport through skin for color prediction of port wine stain lesions: a review.

A survey of the literature is presented regarding the simulation of port wine stain (PWS) skin color. Knowledge of PWS features, such as the depths and diameters of affected vessels, is essential for informing laser treatment. These may be determined through the inverse application of a skin model. The techniques which have been applied to achieve this are analyzed in detail. Radiative transfer (RT) is found to be the preferred method of simulation. By far the most common approximations to RT are the diffusion approximations, which have been applied successfully in the past and Monte Carlo techniques, which are now the methods of choice. As the requirements for improvement of laser treatment on an individual basis continues, the needs for further work towards accurate estimations of individual optical coefficients and robust, flexible simulation techniques are identified.

A new morphometric technique for assessment of melanization in skin of guinea pigs.

BACKGROUND: The degree of melanization is an important finding in many skin disorders. An objective measurement of melanin density is needed to achieve an accurate evaluation. OBJECTIVES: The present work aims at translating the subjective increase of melanin particles after narrow band ultraviolet-B (NB-UVB) irradiation into objective numerical values ready for statistical analysis. MATERIALS AND METHODS: This study had involved 18 guinea pigs that were exposed to biweekly sessions of NB-UVB radiation for 4 weeks to induce skin pigmentation. Two skin biopsies were obtained from each animal; the first before treatment and the second at the end of the study, using 5 mm punch and stained with hematoxylin and eosin and Masson-Fontana (MF) stains. Surface area of both the epidermis (ESA) and the melanin particles (MPSA) were measured in µm(2) using a software supplied with Olympus light microscope. The MPSA/ESA percentage was calculated for each biopsy. The results before and after NB-UVB exposure were compared and statistically analyzed. RESULTS: In the MF-stained sections, the mean ± SD of the MPSA/ESA percentage were 0.24 µm(2) ± 0.09 and 6.21 µm(2) ± 2.45 at the start of the study and at its end, respectively, with a highly significant difference (P < 0.001). CONCLUSION: This technique offers a new methodology for an accurate numerical evaluation of epidermal melanization.

Three-dimensional Monte Carlo model of pulsed-laser treatment of cutaneous vascular lesions.

We present a three-dimensional Monte Carlo model of optical transport in skin with a novel approach to treatment of side boundaries of the volume of interest. This represents an effective way to overcome the inherent limitations of "escape" and "mirror" boundary conditions and enables high-resolution modeling of skin inclusions with complex geometries and arbitrary irradiation patterns. The optical model correctly reproduces measured values of diffuse reflectance for normal skin. When coupled with a sophisticated model of thermal transport and tissue coagulation kinetics, it also reproduces realistic values of radiant exposure thresholds for epidermal injury and for photocoagulation of port wine stain blood vessels in various skin phototypes, with or without application of cryogen spray cooling.

Objective and longitudinal assessment of dermatitis after postoperative accelerated partial breast irradiation using high-dose-rate interstitial brachytherapy in patients with breast cancer treated with breast conserving therapy: reduction of moisture deterioration by APBI.

PURPOSE: To objectively evaluate the radiation dermatitis caused by accelerated partial breast irradiation (APBI) using high-dose-rate interstitial brachytherapy. PATIENTS AND METHODS: The skin color and moisture changes were examined using a newly installed spectrophotometer and corneometer in 22 patients who had undergone APBI using open cavity implant high-dose-rate interstitial brachytherapy (36 Gy in six fractions) and compared with the corresponding values for 44 patients in an external beam radiotherapy (EBRT) control group (50-60 Gy in 25-30 fractions within 5-6 weeks) after breast conserving surgery. RESULTS: All values changed significantly as a result of APBI. The extent of elevation in a∗ (reddish) and reduction in L∗ (black) values caused by APBI were similar to those for EBRT, with slightly delayed recovery for 6-12 months after treatment owing to the surgical procedure. In contrast, only APBI caused a change in the b∗ values, and EBRT did not, demonstrating that the reduction in b∗ values (yellowish) depends largely on the surgical procedure. The changes in moisture were less severe after APBI than after EBRT, and the recovery was more rapid. The toxicity assessment using the Common Toxicity Criteria, version 3, showed that all dermatitis caused by APBI was Grade 2 or less. CONCLUSION: An objective analysis can quantify the effects of APBI procedures on color and moisture cosmesis. The radiation dermatitis caused by APBI using the present schedule showed an equivalent effect on skin color and a less severe effect on moisture than the effects caused by standard EBRT.

Organ transplant recipients and skin cancer: assessment of risk factors with focus on sun exposure.

BACKGROUND: Organ transplant recipients (OTRs) have an increased risk of developing skin cancer, especially epithelial tumours. A number of factors such as immunosuppression, age, ultraviolet radiation and skin type are considered as important in aetiology. OBJECTIVES: The purpose of this study was to further evaluate the risk factors for OTRs regarding skin cancer after transplantation. A detailed investigation of the specific compounds of sun exposure was realised. METHODS: A questionnaire-based study was performed in a specialist OTR dermatology clinic from January to April 2009. The subjects were 70 organ transplanted patients who had developed some form of skin cancer after transplantation. As controls served 69 organ transplanted patients who had no history of skin cancer. The controls were matched concerning age, transplanted organ and gender. Photo protection, sun exposure and transplantation data were part of the questionnaire. Statistical analysis was performed with Mann-Whitney-U-test, chi-square test or Fisher's exact test. RESULTS: The total sun burden (TSB) and the recreational sun exposure in particular attained higher scores in the skin cancer group (TSB-score: mean 11.8 vs. 10.0, P<0.05; recreational sun exposure: mean 6.3 vs. 5.1, P<0.05). The skin cancer group had fairer skin types than the control group (median skin type 2 vs. 3, P<0.05). The OTRs who developed skin cancer have been more likely to have a history or present intake of azathioprine (mean 42% vs. 21%, P<0.05). Also, the skin cancer group has been transplanted for a longer time (mean 12.3 vs. 7.2 years, P<0.001), analogously had a younger age at transplantation (mean 49.5 vs. 52.7 years, P<0.001). CONCLUSIONS: Recreational sun exposure is of central importance for OTRs. A long period of transplantation and thus immunosuppression presents a main risk factor for the development of skin cancer in OTRs. A multi disciplinary management with the best medication and a focus on sun protection is needed to prevent skin cancer in OTRs.

In vivo assessment of pigmentary and vascular compartments changes in UVA exposed skin by reflectance-mode confocal microscopy.

Exposure of the skin to ultraviolet A (UVA) results in various biological responses, skin-colour changes being among the major ones. Although intense research has been performed on UVA-induced pigmentation and vascular changes, the process of skin-colour changes after UVA irradiation remains unclear. For a better understanding of the UVA tanning mechanism, we here performed a human study in 27 healthy volunteers with skin phototype (SPT) II to VI. After a single UVA exposure to inner forearm, the skin sites were imaged using reflectance-mode confocal microscopy (RCM), for analysis of melanin and vascular changes. Punch biopsies were also taken from the UVA-exposed or non-exposed sites for histological examination. Skin sections were stained with Fontana-Masson and evaluated by a sensitive tyrosinase assay for comparison with RCM images. Furthermore, the effect of blood flow on skin-colour changes was evaluated visually after administration of an intradermal anesthesia of lidocaine with or without epinephrine. Our RCM analysis showed dendritic melanocytes and a different melanin distribution in the epidermal layer, clearly visible 1 week after the UVA exposure in subjects of SPT V which were supported by histological examination. However, no melanin distribution pattern changes were apparent immediately after the exposure, while RCM images showed accelerated capillary flow patterns. The restriction of this UVA induced-accelerated blood flow by epinephrine inhibited partially or completely the immediate pigment darkening and delayed tanning. These in vivo studies confirmed that vascular change is an important factor for the development of the immediate pigment darkening and delayed tanning.

[Excimer laser treatment of vitiligo -- critical retrospective assessment of own results and literature overview]. / Excimer-Laser bei Vitiligo -- Kritische Wertung eigener retrospektiver Behandlungsergebnisse und Literaturübersicht.

BACKGROUND: In numerous studies the 308-nm excimer laser has been described as an effective therapy method for localized vitiligo. Our experience and critical evaluation of the relevant literature lead to a less enthusiastic endorsement. PATIENTS AND METHODS: A total of 9 patients with localized vitiligo were evaluated in our retrospective study. The sessions took place 2-3 times per week; the energy dose was increased depending on the occurring side effects. The rate of repigmentation was evaluated in 5 grades: grade 0 = 0 %, grade 1 = 1-25 %, grade 2 = 26-50 %, grade 3 = 51-75 %,grade 4 = 76-100 %. Subjective patient satisfaction was rated "satisfied"/"not satisfied". RESULTS: In face and neck areas we used a cumulative energy dose of 16.6 J/cm(2) and achieved repigmentation grade 4 in 33.3 %, grade 2 in 33.3 %, grade 1 in 11.1 % and no improvement in 22.2 % of the cases. On hands and knees we used a medium cumulative energy dose of 20.8 J/cm(2) and did not observe any tendency towards repigmentation. Four of the patients were satisfied, while 5 were not. Side effects (erythema, blisters, crusting and perilesional hyperpig-mentation) were transient in all cases. Within a medium observation period of 19.1 months, one patient had a relapse. CONCLUSIONS: The excimer laser should be regarded as a treatment alternative in cases of localized vitiligo of the face. The treatment at other sites is clearly limited because of only partial repigmentation, considerable expense of time and money as well as the potentially higher risk of tumorigenesis.

Assessment of the usefulness of skin phototype and skin color as the parameter of cutaneous narrow band UVB sensitivity in psoriasis patients.

BACKGROUND: Many reports have been released to assess skin types, skin colors and cutaneous sensitivity to broad band UVB or UVA. OBJECTIVE: This study was performed to investigate the usefulness of skin type and skin color as the parameter of narrow band UVB (NBUVB) sensitivity. METHODS: The minimal erythema dose (MED) of 40 psoriasis patients was investigated by irradiating several doses ranging from 200 to 1500 mJ/cm2. Before phototesting, the skin color of buttock was measured with a tristimulus colorimeter. RESULTS: The median and mode value of MED of NBUVB was 950 mJ/cm2. Skin type was well correlated with the MED and there was a significant relationship between the L* value and MED, but not for the a* and b* values. CONCLUSION: The MED value of NBUVB in our study is a basic data to set the phototherapy protocol. Our result showed that skin type and L* value might be useful for predicting the sensitivity to NBUVB irradiation.

Quantitative assessment of narrow-band UVB induced tanning during phototherapy in Korea.

BACKGROUND/PURPOSE: Narrow-band (TL-01) UVB lamps are being increasingly used for phototherapy of psoriasis and other dermatoses, for their excellent effect compared with broad-band UVB sources. Many patients receiving phototherapy have complained about the tanning effect of ultraviolet radiation especially in dark-skinned ones. So we wished to know the degree of pigmentation induced by phototherapy during narrow-band UVB treatment. METHODS: A total of 20 psoriasis patients receiving narrow-band UVB phototherapy were included in this study. A Minolta spectrophotometer CM-2002 was used to measure pigmentation. All patients were evaluated for skin color every seventh day for 7 weeks. The L* value (luminance) gives information about the relative lightness ranging from total black to pure white. The a* value represents the balance between red and green, and the b* value between yellow and blue. RESULTS: The L* values which indicate luminance decreased continuously until the 5th week, when maximum tanning was obtained. Afterwards minimal change was observed until the 7th week. The change of a* and b* values also showed the pattern that was compatible with the above results. The mean individual typology angle of our subjects was 41.9 degrees, which indicated they fell into "light" group of constitutional skin color category. CONCLUSION: From this study, we found that pigmentation induced by narrow-band UVB phototherapy increased continuously until the 5th week and then did not progress. Our results provide standard data of skin pigmentation during narrow-band UVB phototherapy in Korean brown skin.