Current problems in dermatology最新文献

Organic and inorganic ultraviolet (UV) filters are used in topical sunscreens and other applications to prevent or limit damage following exposure to UV light. Increasing use of UV filters has contributed to a growing number of investigations examining potential effects on human health and the environment. Worldwide environmental monitoring data demonstrate that UV filters reach aquatic environments through two main input sources - direct (i.e., washoff from swimmers/bathers) and indirect (i.e., incomplete wastewater treatment removal) - and can be taken up by various algal, plant, and animal species and sediments. In areas where industrial wastewater sources or significant recreational activities result in a greater input load, levels may be elevated and could impart an increased risk on native species health. In vitro, at higher levels typically not measured in the environment, effects on growth and reproduction are observed in different species, including fish, coral reef, and plants. Despite this, predicted no-effect concentrations for UV filters are generally above measured environmental concentrations. Recent legislative activity banning the use of certain UV filters has heightened awareness of their environmental ubiquity and precipitated a need for a thorough examination of evidence linking their ecological presence with adverse outcomes. In order to gauge the true potential risk to native ecosystems associated with UV filters, future studies should consider factors inherent both to finished sunscreen products (e.g., metabolic fate/transport and effect of inactive ingredients) and to the sampled environment (e.g., species sensitivity, presence of other contaminants, water flow, and photodegradation).

Skin cancer rates have been on the rise for decades and are still growing in spite of the availability of high-performance sunscreens that provide sufficient protection against the damaging effect of UV radiation everywhere on this globe. This paper investigates behaviors and attitudes to sunscreen use that may cause an increased UV exposure risk, for example, not using sunscreen at all. Alongside educational reasons, there is a link to some aspects of applying sunscreens that seem to be disliked universally. Therefore, the sensory features of 73 globally sourced commercial sunscreens were measured using quantitative descriptive sensory analysis. This revealed the ranges of sensory intensity currently available, which were then compared with what consumers really want, and showed that only a few sunscreens currently fulfill the needs of people in the most abundant consumer group - "dry touch seekers." All this contributes to insufficient or no use at all of sunscreens during sun exposure, which could result in significant UV dosages that turn out to be relevant for skin cancer development. A more integral approach to improving sunscreen formulas, along with more targeted communication to connect more effectively with consumers who currently show those avoidance behaviors, is needed.

Since the beginning of the development of sunscreen products, efforts have been made to measure and quantify the protection performance of such products. Early on an in vivo method was established that allowed statements on the sun protection performance in humans. Later, by establishing defined basic and experimental conditions, the method became internationally standardized delivering the well-known sun protection factor (SPF). The method was widely used and is nowadays regarded as a gold-standard method. Further standardized methods were added shortly thereafter. However, shortcomings such as the confined radiation spectra used by the methods, the invasiveness, the complexity in their application, as well as their time- and cost-intensity promoted the development of alternative methods. The shortcomings were recently followed by another, namely, the large interlaboratory variances of the sun protection metrics SPFISO 24444. This all together shows that there is a justifiable need to explore the potential of alternative methods, to complement the existing methods, to serve as equivalents, or even to replace it in the future. Based on the work of Uhlig and coworkers, the authors propose to test the suitability of the alternative methods and their possible equivalency to the reference methods in a broad-based investigation, taking into account possible interlaboratory variances. A research program - developed by a consortium - is in public planning where stakeholders from research, industry, authorities, and the public can come together to facilitate and further advance standardization of the measurement of the sun protection performance. The authors give an insight into historical, technical--conceptual, and future developments of methods for -determining the protective performance of sun protection products.

Background: With more than 200,000 new cases per year, skin tumours have been the most frequently reported cancers in Germany for years. We performed a systematic review to summarise the current evidence concerning the preventive value of regular sunscreen use.

Methods: Systematic literature review of controlled and randomised controlled trials were performed in Ovid Embase and Ovid Medline on 21 January 2020. We included studies evaluating the effectiveness of sunscreens on epithelial skin cancer, actinic keratosis or photoageing, or side effects in humans.

Results: Five eligible trials, each involving 28 to 1,621 participants from various populations, were identified. All 4 studies on actinic keratoses showed a significant beneficial effect of sunscreens. The 2 studies on squamous cell carcinoma demonstrated significant beneficial effects of sunscreens. The 2 studies on photoageing observed a significant reduction in the sunscreen groups. The 2 studies on basal cell carcinoma reported no significant results, but both studies reported some non-significant protective effects of sunscreen use. Sunscreens as well as vehicles sometimes had side effects affecting skin and eyes. Compared with controls, sunscreens had no significant side effects on vitamin D, bone mass density and mortality.

Conclusion: The evidence from published controlled and randomised controlled studies is limited. Especially for basal cell carcinoma, further high-quality studies including young populations are required to investigate possible protective effects of modern broad-spectrum sunscreens. The results of this systematic review do not change the current recommendations for UV protection. Sunscreens are recommended as a second-line measure against solar radiation whenever protective clothing and seeking shake are inadequate.

Although skin is a vital barrier to the outside world, it is permeable to certain substances used in topical pharmacotherapy. It is therefore not surprising that other xenobiotics intentionally or accidentally coming in contact with skin can cross the skin barrier. Long before the turn of the millennium, it became clear that sunscreen filters from sunscreen products can be systemically absorbed and detected in urine and plasma. Against this background, we review issues and challenges with safety assessments related to the possible percutaneous absorption of the sunscreen filters. A reference is made to the Regulation (EC) No. 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products (version 1 August 2018) and the concepts of the Maximal Usage Trial (MUsT) and Generally Recognized As Safe and Effective (GRASE), currently discussed in the United States.

Effective skin protection of consumers by sunscreens can only be achieved when meaningful and reliable test methods are available to objectively measure the protection of sunscreen products. Quantitative, scientifically sound, and valid methods to detect UVB and UVA light protection as well as methods to assess sunscreen substantivity to water are required. Continuous improvement and, if necessary, extension of the test methods are important to provide optimum protection from harmful sun rays to the consumer. This work documents the historical background of the development of sunscreen test methods and provides the actual worldwide status of applied methods. Future developments and trends are discussed as far as they actually become apparent.

Sunscreens used for the protection of human skin work by attenuating the potentially harmful solar UV radiation. In recent years, the quantitative understanding of this attenuating effect has grown tremendously, enabling model calculations of sunscreen performance. Such calculations are based on the simulation of the UV transmission of the sunscreen film applied on human skin. However, there are 2 prerequisites assumed to hold. The first prerequisite is the applicability of the Beer-Lambert law for sunscreen films, and the second is that the thickness variation of the sunscreen film can be described with a gamma distribution of film heights. There is strong evidence from recent experimental work that both assumptions are correct. For several applications, calculations of sunscreen performance have been shown to be useful, for instance, in the design of new sunscreen formulations aiming for a certain sun protection factor or other characteristics, prediction of pre-vitamin D production in the skin in the presence of sunscreen, in vitro measurement of water resistance, and assessment of the ecotoxicological profile of a sunscreen formulation or the influence of oil polarity on UV-filter absorbance and the consequence for sunscreen performance.

Preparations containing pigments have been used since ancient times to protect against negative effects of solar radiation. Since the 1950s, sunscreen products containing micronized TiO2 and ZnO have been marketed. These products were soon regarded as cosmetically unattrac-tive due to their property of remaining as a white paste on the skin, a result of particle sizes. In order to eliminate these unfavourable properties, particle size distribution was lowered into a range below 100 nm, a size threshold for decreasing the particle's optical property to reflect visible light. After 2000, new nanoparticulate organic filters were developed. Effects of both the inorganic and organic nanoparticulate substances - alone or in combination - with non-particulate UV filters were well documented and had shown great effectiveness. At the time, nanotechnology fuelled great hope in the progress of science and technology, including the health sector and cosmetics industry. Instead, influenced by images from the science fiction literature of self-replicating nanorobots destroying all living matter or health and environmental disasters caused by asbestos, fear of this new unknown amongst the general population has hindered acceptance and progress of nano-enabled products. Consumers have started to suspect that the particles permeate through skin, are absorbed by the blood and are distributed throughout the body, causing disease. Not least because of public pressure, cosmetics - which include sunscreen products - became the first product segment in which appropriately manufactured substances were subject to stringent rules. Despite advanced regulation and rigorous approval procedures for nanoparticulate UV filters, widespread reservations remain. Possible reasons could be a lack of knowledge of current legislation and unclear ideas about nature and behaviour of nanoparticles. Against this background, we discuss the nature and behaviour of nanoparticulate UV filters within finished products, on the skin and potentially in the skin, and the regulatory framework that ensures that nanoparticulate UV filters and the sunscreen products containing them are safe to use.

While UV radiation is a skin carcinogen, this should not obscure the growing evidence that sunlight has significant health benefits, including impacts on cardiovascular and metabolic health. Epidemiological and mechanistic evidences for the importance of different wavelengths of sunlight, including blue light and UV radiation, are presented.

Developing efficient sunscreen products with an acceptable sensory feel after application on skin, that meet current regulatory market and consumer requirements, is a major challenge, exacerbated by new restrictions limiting the use of certain ingredients previously considered crucial. This paper outlines a development strategy for -formulating sunscreens along a generic professional development pathway. Each galenic system will be different and must be customized. Development starts with benchmarking, followed by UVA/UVB filter platform selection and in silico calculation/optimization of photoprotection performance for the desired SPF, UVA-PF, and other requested endpoints. Next comes the selection of the emulsifier system and other key formulation ingredients, such as oil components, triplet quenchers, and antioxidants, with sensory, rheological, and film formation functions. Preliminary cost estimation is then performed to -complete the conceptual process before the start of the practical galenic development. The successful development of modern sunscreen products is based on -comprehensive expertise in chemistry, galenic methodology, regulation, and patenting, as well as specific -market and consumer requirements. The selection of the UV filters is the first key decision and constrains later choices. Other properties, such as water resistance and preservation or active ingredients, may need to be considered. The 4 basic requirements of efficacy, safety, registration, and patent freedom become checklist items to ensure that after development, a sunscreen product has a chance of success.