Sunscreens: Misconceptions and Misinformation.

Over the past 70 years, sunscreens have evolved from beach products designed to prevent sunburn to more cosmetically elegant skincare products intended to protect against multiple long-term adverse consequences of characteristically low-intensity daily UV and visible light exposure. Sunscreen testing and labeling intended to quantify such protection are unfortunately often misunderstood by users and have also led to illegal misleading and potentially dangerous industry practices. Changes in regulatory requirements, better policing, and more informative sunscreen labeling would benefit users and their physician advisors.

Patch Testing With Benzophenone-3 and -4: The North American Contact Dermatitis Group Experience, 2013-2020.

Background: Benzophenone (BZP)-3 and BZP-4 are ultraviolet (UV) absorbers used in sunscreens and personal care products (PCPs) and may cause allergic contact dermatitis. Objective: To characterize positive patch test reactions to BZP-3 (10% in petrolatum [pet]) and BZP-4 (2% pet) in a screening allergen series. Methods: Retrospective analysis of patients tested to BZP-3 and BZP-4 was conducted by the North American Contact Dermatitis Group from 2013 to 2020. Results: Of 19,618 patients patch tested to BZP-3 and BZP-4, 103 (0.5%) and 323 (1.6%) had positive reactions, respectively: 413 (2.1%) reacted to at least 1 BZP (BZP-positive patient). As compared with BZP-negative patients, BZP-positive patients were significantly more likely to have a history of hay fever (39.3% vs 33.4%, P = 0.0134), history of atopic dermatitis (39.8% vs 30.7%, P = 0.0001), and facial involvement (37.4% vs 32.2%, P = 0.0272). Most reactions were currently clinically relevant (BZP-3: 90.4%; BZP-4: 65.8%). Common identified sources included PCPs and sunscreens. Coreactivity between BZP-3 and BZP-4 was low: 13.5% (14/104) of BZP-3-positive patients were allergic to BZP-4 and 4.3% (14/322) of BZP-4-positive patients were allergic to BZP-3. Conclusions: Eight-year prevalence of BZP positivity was 2.1%. Reactions were frequently clinically relevant and linked to PCPs and sunscreens.

Benzophenone-3: Comprehensive review of the toxicological and human evidence with meta-analysis of human biomonitoring studies.

BACKGROUND: Benzophenone-3 (BP-3) and its major metabolite benzophenone-1 (BP-1) are widely used as UV filters in sunscreens and cosmetics to prevent sunburn and skin damage, or as stabilizers to prevent photodegradation in many commercial products. As a result, their presence is ubiquitous in the environment, wildlife and humans. Based on endocrine disruption concerns, international regulatory agencies are performing a closer evaluation. OBJECTIVE AND METHODS: This work aimed to comprehensively review the available human relevant evidence for safety issues in MEDLINE/PubMed in order to create a structured database of studies, as well as to conduct an integrative analysis as part of the Human Biomonitoring for Europe (HBM4EU) Initiative. RESULTS: A total of 1,635 titles and abstracts were screened and 254 references were evaluated and tabulated in detail, and classified in different categories: i) exposure sources and predictors; ii) human biomonitoring (HBM) exposure levels to perform a meta-analysis; iii) toxicokinetic data in both experimental animals and humans; iv) in vitro and in vivo rodent toxicity studies; and v) human data on effect biomarkers and health outcomes. Our integrative analysis showed that internal peak BP-3 concentrations achieved after a single whole-body application of a commercially available sunscreen (4% w/w) may overlap with concentrations eliciting endocrine disrupting effects in vitro, and with internal concentrations causing in vivo adverse female reproductive effects in rodents that were supported by still limited human data. The adverse effects in rodents included prolonged estrous cycle, altered uterine estrogen receptor gene expression, endometrium hyperplasia and altered proliferation and histology of the mammary gland, while human data indicated menstrual cycle hormonal alterations and increased risk of uterine fibroids and endometriosis. Among the modes of action reported (estrogenic, anti-androgenic, thyroid, etc.), BP-3 and especially BP-1 showed estrogenic activity at human-relevant concentrations, in agreement with the observed alterations in female reproductive endpoints. The meta-analysis of HBM studies identified a higher concern for North Americans, showing urinary BP-3 concentrations on average 10 and 20 times higher than European and Asian populations, respectively. DISCUSSION AND CONCLUSIONS: Our work supports that these benzophenones present endocrine disrupting properties, endorsing recent European regulatory efforts to limit human exposure. The reproducible and comprehensive database generated may constitute a point of departure in future risk assessments to support regulatory initiatives. Meanwhile, individuals should not refrain from sunscreen use. Commercially available formulations using inorganic UV filters that are practically not absorbed into systemic circulation may be recommended to susceptible populations.

Shedding a light on the importance of photopatch testing: A 12-year experience in a dermatology unit.

BACKGROUND: Photopatch testing has been standardized for diagnosing photoallergic contact dermatitis but is still infrequently used. OBJECTIVES: To characterize photopatch test (PPT) results and their clinical relevance. METHODS: We collected retrospective data from patients photopatch tested in our Dermatology Unit (2010-2021), using the European PPT 'baseline' series, other allergens, and patient's own products, when appropriate. RESULTS: Out of 223 patients, 75 patients (33.6%) were reactive with 124 positive PPT reactions, considered relevant in 56/223 patients (25.1%) and in 72/124 reactions (58.1%). Most reactions were caused by topical drugs (n = 33; 45.8%), such as ketoprofen or promethazine, and 7 (9.8%) by systemic drugs, such as hydrochlorothiazide and fenofibrate. 'Classical' ultraviolet filters were responsible for six positive PPT reactions whereas there was only three relevant PPT to the 'newer' UV filters. Patients' sunscreens/cosmetics or plant extracts caused 10 positive PPT each. Additional patch test reactions were observed, mostly to Tinosorb® M. CONCLUSION: Contrary to the trend in ACD, most positive PPT reactions were caused by topical drugs, outweighing ultraviolet filters and cosmetics. We stress the low reactivity to the 'newer' UV filters included in the PPT series. PPT was occasionally positive in systemic drug photosensitivity, but overall PPT reactivity was low.

Sunscreens: A Review of UV Filters and Their Allergic Potential.

Abstract Active ingredients of sunscreens, or UV filters, have increased in use because public awareness of sun safety has risen. In addition to this intentional use, unintentional exposures to UV filters also occur through application of personal care products, where the filters are incorporated into the product. There are 2 main types of UV filters: organic (chemical) filters and the 2 inorganic (mineral) filters, titanium dioxide and zinc oxide. Both allergic contact dermatitis (ACD) and photoallergic contact dermatitis (PACD) have been caused by organic filters; oxybenzone (benzophenone-3) is the most frequently reported contact and photocontact allergen compared with all other UV filters. There are no reports of ACD or PACD to the inorganic (physical) UV filters. Here, we review the categories of sunscreens available, currently marketed UV filters, and their corresponding ACD and PACD.

Review on photoprotection: a clinician's guide to the ingredients, characteristics, adverse effects, and disease-specific benefits of chemical and physical sunscreen compounds.

Photoprotection is a critical health prevention strategy to reduce the deleterious effects of ultraviolet radiation (UVR) and visible light (VL). Methods of photoprotection are reviewed in this paper, with an emphasis on sunscreen. The most appropriate sunscreen formulation for personal use depends on several factors. Active sunscreen ingredients vary in their protective effect over the UVR and VL spectrum. There are dermatologic diseases that cause photosensitivity or that are aggravated by a particular action spectrum. In these situations, sunscreen suggestions can address the specific concern. Sunscreen does not represent a single entity. Appropriate personalized sunscreen selection is critical to improve compliance and clinical outcomes. Health care providers can facilitate informed product selection with awareness of evolving sunscreen formulations and counseling patients on appropriate use. This review aims to summarize different forms of photoprotection, discuss absorption of sunscreen ingredients, possible adverse effects, and disease-specific preferences for chemical, physical or oral agents that may decrease UVR and VL harmful effects.

Incidence of melanoma and non-melanoma skin cancer in patients with celiac disease: a systematic review and meta-analysis.

There is conflicting observational evidence regarding the association between skin cancer and celiac disease (CD). The purpose of this review was to investigate the incidence rate ratio (IRR) of skin cancer incidence between patients with and without CD. MEDLINE and EMBASE databases were searched on October 27th, 2021 and eight articles were identified for review. Quality assessment was conducted using the Newcastle Ottawa Scale. Seven articles were included in meta-analysis for a pooled estimate of IRR across all skin cancers, malignant melanoma (MM), and non-melanoma skin cancers (NMSC). In total, 74,860 CD patients were followed for 710,214 person-years in the meta-analysis. Overall combined incidence was 99.8 cases per 100,000 person-years. Meta-analysis of all skin cancer incidence showed no significant difference in CD patients compared to controls (IRR: 1.06; 95% CI: 0.95, 1.17; p=0.29; I2: 0%). Five studies reported on MM incidence; there was no significant difference in incidence compared to controls (IRR: 0.87, 95% CI: 0.72, 1.06; p=0.22; I2: 9%). Five studies reported on NMSC incidence, revealing a significantly increased risk of NMSC in CD patients (IRR: 1.14; 95% CI: 1.01, 1.28; p=0.04; I2: 0%). Our findings suggest a significantly increased incidence of NMSC in CD patients compared to control data and no significant association between CD and MM incidence. The findings are limited by the quantity and quality of the evidence. Nonetheless, clinicians should emphasize the importance of sun protection, such as sunscreen usage and self-examination for patients with CD.

Impacto de los filtros ultravioleta en el entorno natural / Environmental Impact of UV Filters

Los filtros ultravioleta (UV) se han convertido en compuestos de uso diario para millones de personas. Sin embargo, algunos de ellos no son biodegradables al 100% y las plantas de tratamiento de aguas residuales muchas veces no son capaces de filtrarlos correctamente. Todo ello está llevando a su diseminación ambiental y a la detección de distintos filtros UV en el suelo, las aguas continentales, los océanos y en múltiples organismos (algas, corales, peces, mamíferos, incluso aves terrestres). Además, algunos filtros UV, especialmente la benzofenona-3 y el octocrileno se han mostrado tóxicos en estos organismos. Entre sus efectos tóxicos destacamos el blanqueamiento de los corales y problemas metabólicos, enzimáticos y de capacidad reproductiva en prácticamente cualquier organismo. Existen datos preliminares sobre la posible bioacumulación de estos filtros UV en humanos, al detectarse en muestras de orina y leche materna. Sin embargo, el estudio del impacto medioambiental de los filtros UV presenta muchas limitaciones (AU)

UV filters are used daily by millions of people. Not all of these filters, however, are 100% biodegradable, and many wastewater treatments plants are ill-equipped to filter them properly. As a result, UV filters are increasingly reaching the environment. Various types have been detected in soil, continental water, oceans, and numerous organisms, including algae, corals, fish, mammals, and even land birds. In addition, some filters, benzophenone-3 and octocrylene in particular, are toxic to these organisms. Toxic effects include coral bleaching and interference with metabolic, enzymatic, and reproductive activities in practically all organisms. Preliminary data suggest that UV filters may be bioaccumulating in humans, as they have been detected in urine and breast milk. It should be noted, however, that research into the environmental impact of UV filters holds challenges and limitations (AU)

[Translated article] Environmental Impact of UV Filters / Impacto de los filtros ultravioleta en el entorno natural

UV filters are used daily by millions of people. Not all of these filters, however, are 100% biodegradable, and many wastewater treatments plants are ill-equipped to filter them properly. As a result, UV filters are increasingly reaching the environment. Various types have been detected in soil, continental water, oceans, and numerous organisms, including algae, corals, fish, mammals, and even land birds. In addition, some filters, benzophenone-3 and octocrylene in particular, are toxic to these organisms. Toxic effects include coral bleaching and interference with metabolic, enzymatic, and reproductive activities in practically all organisms. Preliminary data suggest that UV filters may be bioaccumulating in humans, as they have been detected in urine and breast milk. It should be noted, however, that research into the environmental impact of UV filters holds challenges and limitations (AU)

Los filtros ultravioleta (UV) se han convertido en compuestos de uso diario para millones de personas. Sin embargo, algunos de ellos no son biodegradables al 100% y las plantas de tratamiento de aguas residuales muchas veces no son capaces de filtrarlos correctamente. Todo ello está llevando a su diseminación ambiental y a la detección de distintos filtros UV en el suelo, las aguas continentales, los océanos y en múltiples organismos (algas, corales, peces, mamíferos, incluso aves terrestres). Además, algunos filtros UV, especialmente la benzofenona-3 y el octocrileno se han mostrado tóxicos en estos organismos. Entre sus efectos tóxicos destacamos el blanqueamiento de los corales y problemas metabólicos, enzimáticos y de capacidad reproductiva en prácticamente cualquier organismo. Existen datos preliminares sobre la posible bioacumulación de estos filtros UV en humanos, al detectarse en muestras de orina y leche materna. Sin embargo, el estudio del impacto medioambiental de los filtros UV presenta muchas limitaciones (AU)

What are parents reading about the sunscreen controversy?

The benefits of sunscreen use have been well-established. However, discussion of its risks remains on the internet. Given this point of controversy, a web search of 50 websites on children's sun safety was performed and indicated that the information online is variable and incomplete when informing parents on the benefits and risks of sunscreen use.

Frontal Fibrosing Alopecia and Sunscreen Use: A Cross-sectional Study of Actinic Damage.

Patients with frontal fibrosing alopecia report higher rates of sunscreen use than control subjects. However, it is not known whether the higher use of sunscreens is a cause or a consequence of the alopecia. A greater use of sunscreens should be associated with a lower incidence of signs of actinic damage. The aim of this study is to assess the presence of actinic damage in patients with frontal fibrosing alopecia. A cross-sectional study was carried out on 101 patients with frontal fibrosing alopecia and 40 control subjects. The presence of actinic damage, in the form of solar lentigines, actinic keratoses, and basal and squamous cell carcinomas, was recorded in both groups, together with sunscreen use. Trichoscopy and skin biopsy were performed on patients. Actinic damage was present more frequently in patients with frontal fibrosing alopecia (69.3%) than in control subjects (50%) (p = 0.031). Patients used sunscreens more frequently than did control subjects (83.2% vs 62.5%, p = 0.008). However, the prevalence of trichoscopic inflammatory signs, peripheral alopecia, and inflammatory infiltrate and sebaceous gland involvement in skin biopsy, were similar in patients who used sunscreens and those who did not use them. In conclusion, patients with frontal fibrosing alopecia had greater actinic damage than did control subjects, and this is hypothesized as a reason for the higher use of sunscreens among patients. Thus, use of sunscreens may not be the trigger for frontal fibrosing alopecia that dermatologists have proposed.

Effectiveness, compliance and application of sunscreen for solar ultraviolet radiation protection in Australia.

Objectives and importance of study: Sunscreens are widely used, not only to prevent acute sunburn, but also for skin cancer prevention and protection against photoaging and other skin conditions related to cumulative solar ultraviolet radiation (UVR) exposure. When correctly applied, sunscreens reduce the amount of UVR reaching the skin and therefore they can reduce harmful effects of such exposures. This paper examines the benefits and risks of sunscreens, compliance requirements and how sunscreen should be used for optimal effectiveness. STUDY TYPE: Narrative review. METHODS: We reviewed evidence relating to the benefits and risks of sunscreens, sunscreen manufacturing compliance, consumer usage of sunscreen and how sunscreen should be used to be most effective. RESULTS: There is strong evidence that sunscreen is safe to use and, when applied correctly, reduces the risk of skin cancer. There is a need to address questions about the impact of sunscreen on vitamin D and its risk to the environment, as well as a need to develop sun protection factor (SPF) sunscreen testing methods that are more reproducible and ethically based. The amount of sunscreen and the way it is applied varies considerably between individuals, and this in turn markedly affects the degree and duration of protection received. Sunscreen should be used in combination with other sun protection measures that include clothing, hats, sunglasses and seeking shade. CONCLUSIONS: Regulation is essential to ensure high-quality, safe and effective sunscreen products are available to the Australian population. There is an important role for governments to put in place skin cancer prevention policies and long-term funding arrangements to build on our successful sunscreen programs so that future generations are afforded the highest level of topical protection against solar UVR.

Vaccinium myrtillus L. extract associated with octocrylene, bisoctrizole, and titanium dioxide: in vitro and in vivo tests to evaluate safety and efficacy.

OBJECTIVE: The harmful effects induced by ultraviolet exposition and the significant increment in skin cancer diagnosis confirm the necessity to develop effective and safe sunscreens. Limited efficacy and cutaneous adverse reactions of traditional formulations drove the incorporation of natural extracts into multifunctional sunscreens. Vaccinium myrtillus L. extract (VME), that contains anthocyanins and flavonoids, is a potential candidate for such systems. METHODS: Considering that, we performed in vitro and in vivo tests to evaluate the sun protection factor (SPF), photostability, and safety of sunscreen samples containing VME. RESULTS: As main results, the SPF was reduced in both in vitro and in vivo evaluation in the presence of VME; nonetheless, the samples were photostable and safe. CONCLUSION: Further investigation is required to better understand the unexpected effects of VME over photoprotection, decreasing the SPF value. As a conclusion, even with interesting findings, we highlight the importance of case-by-case investigations to develop multifunctional bioactive sunscreens.

Photoallergic Contact Dermatitis: No Fun in the Sun.

Photoallergic contact dermatitis (PACD) is a form of allergic contact dermatitis that occurs due to the interaction between a topically applied chemical and exposure to UV radiation. It can be difficult to identify and requires photopatch testing (PPT) for definitive diagnosis. In this article, we provide an overview of PACD, including clinical features, the most common photoallergens, and why cases may go undiagnosed.