Effect of daily versus intermittent sunscreen application on solar simulated UV radiation-induced skin response in humans

Comparison of photodamage in non-pigmented and pigmented human skin equivalents exposed to repeated ultraviolet radiation to investigate the role of melanocytes in skin photoprotection

Introduction

Daily solar ultraviolet (UV) radiation has an important impact on skin health. Understanding the initial events of the UV-induced response is critical to prevent deleterious conditions. However, studies in human volunteers have ethical, technical, and economic implications that make skin equivalents a valuable platform to investigate mechanisms related to UV exposure to the skin. In vitro human skin equivalents can recreate the structure and function of in vivo human skin and represent a valuable tool for academic and industrial applications. Previous studies have utilised non-pigmented full-thickness or pigmented epidermal skin equivalents to investigate skin responses to UV exposure. However, these do not recapitulate the dermal-epidermal crosstalk and the melanocyte role in photoprotection that occurs in vivo. In addition, the UV radiation used in these studies is generally not physiologically representative of real-world UV exposure.

Methods

Well-characterised pigmented and non-pigmented skin equivalents that contain human dermal fibroblasts, endogenous secreted extracellular matrix proteins (ECM) and a well-differentiated and stratified epidermis have been developed. These constructs were exposed to UV radiation for ×5 consecutive days with a physiologically relevant UV dose and subsequently analysed using appropriate end-points to ascertain photodamage to the skin.

Results

We have described that repeated irradiation of full-thickness human skin equivalents in a controlled laboratory environment can recreate UV-associated responses in vitro, mirroring those found in photoexposed native human skin: morphological damage, tanning, alterations in epidermal apoptosis, DNA lesions, proliferation, inflammatory response, and ECM-remodelling.

Discussion

We have found a differential response when using the same UV doses in non-pigmented and pigmented full-thickness skin equivalents, emphasising the role of melanocytes in photoprotection.

The effect of on-site application density on the UV protection efficacy of sunscreens

BACKGROUND

Sun protection factor (SPF) and UVA protection factor (UVAPF) are performance indicators consumers recognize for UV protective cosmetics such as sunscreens. However, on-site application density affects actual UV protection, despite these indicators. To understand actual UV protection better, a more reliable manner is needed to verify application density for further discussion of photoprotection efficacy regarding public health.

OBJECTIVES

To estimate the UV protective efficacy of sunscreen in actual use based on the application density of UV protective cosmetics and the analysis of UV protective effect modulated by application density.

METHOD

The subjects applied the SPF-labeled sunscreens as usual. We measured the application amount and area including any amount on their hands to calculate the average application density on the face. Also, sunscreens were applied at densities of 0.5, 1.0, and 2.0 mg/cm² . The SPF values were measured at each application site to evaluate the effect of application density on photoprotection efficacy.

RESULT

We established a method of measuring application density utilizing three-dimensional photograph analysis. The median application density of the sunscreen applied in actual use was 1.33 mg/cm² . The measured SPF values decreased in association with the decreased application density of sunscreens. Based on the estimate assuming the first-order correlation, the SPF value required to get the protective effect equivalent to a sunscreen with SPF 15, 30, or 50 at 2 mg/cm² was calculated to be 23.8, 47.5, and 79.2, respectively, with the application density of 1.33 mg/cm² .

CONCLUSION

We demonstrated a reasonable procedure for estimating the photoprotection efficacy of sunscreens on the face. A suggestion was made to consider the application density for further discussion of photoprotection among consumers, especially for the long term with respect to public health.

Stimulating Sunscreen Use Among Outdoor Construction Workers: A Pilot Study

Background

Outdoor workers (OW) receive a higher dose of ultraviolet radiation (UVR) compared to indoor workers (IW) which increases the risk of non-melanoma skin cancer (NMSC). Regular sunscreen use reduces the NMSC risk, however, adequate sun-safety behavior among OW is poor. The main objective was to conduct method- and intervention-related elements of a future intervention trial among OW, based on providing sunscreen and assessing sunscreen use on group- and individual level.

Methods

This pilot study was conducted at a construction site in the Netherlands from May-August 2021. Nine dispensers with sunscreen (SPF 50+) were installed at the worksite. OW (n = 67) were invited to complete two (cross-sectional) questionnaires on sun-safety behavior, before and after providing sunscreen. Stratum corneum (SC) samples for the assessment of UV-biomarkers were collected from the forehead and behind the ear from 15 OW and 15 IW. The feasibility of the following elements was investigated: recruitment, (loss to) follow-up, outcome measures, data collection, and acceptability of the intervention.

Results

The first questionnaire was completed by 27 OW, the second by 17 OW. More than 75 percent of the OW were aware of the risks of sun exposure, and 63% (n = 17) found sunscreen use during worktime important. The proportion of OW never applying sunscreen in the past month was 44.4% (n = 12) before, and 35.3% (n = 6) after providing sunscreen. A majority of OW (59.3%, n = 16) found sunscreen provision encouraging for sunscreen use, the dispensers easy to use (64.7%, n = 17) and placed in practical spots (58.8%, n = 18). Collecting SC-samples was fast and easy, and several UV-biomarkers showed higher levels for sun-exposed compared to less exposed body parts. There was no significant difference in UV-biomarker levels between OW and IW.

Conclusions

This pilot study revealed low sunscreen use among OW despite providing sunscreen, overall satisfaction with the sunscreen, and the sufficient awareness of the risks of UVR-exposure. Collecting SC-samples at the workplace is feasible and several UV-biomarkers showed to be promising in assessing UVR-exposure. The low participation rate and high loss to follow-up poses a challenge for future intervention studies.

Eco-friendly sunscreen formulation based on starches and PEG-75 lanolin increases the antioxidant capacity and the light scattering activity in the visible light

Most modern sunscreens contain physical filters, which scatter the sunlight, increasing the photons' pathway in the upper stratum corneum. This effect can lead to a better efficacy of the UV filters and improve the diffuse reflection. However, the addition of nanosized inorganic UV filters reduces the antioxidant capacity of sunscreen formulations. Two cream formulations (F1, F2) which differ in the ingredient PEG75 Lanolin (F2), have been characterized for their radical protection factor (RPF) and their optical properties in vitro using electron paramagnetic resonance (EPR) spectroscopy and UV/VIS spectrometry. The RPF for PEG-75 Lanolin was also determined. Furthermore, their radical protection properties were analyzed on porcine skin ex vivo after visible light irradiation by EPR. The structure of each formulation in the skin surface was determined by reflectance confocal microscopy in vivo. The addition of lanolin increased the reflectance and reduced the transmittance for visible light, improving the scattering drastically. Besides, the antioxidant capacity was also increased for F2, something unpublished until now. F1 presented a lower scattering provided by starches. The sunscreens showed high scattering properties and antioxidant capacity, especially for F2, which presented the lowest radical formation in the skin model. These results are consistent with the RPF measurements where F2 has a higher RPF value (193 ± 3 × 10¹⁴ radicals/mg) than F1 (155 ± 4 × 10¹⁴ radicals/mg) and for PEG-75 Lanolin (37 ± 1 × 10¹⁴ radicals/mg). The combination of starches and PEG-75 Lanolin is the first solution to provide both, light scattering and antioxidant capacity, in sunscreens.

Stratum corneum biomarkers after in vivo repeated exposure to sub-erythemal dosages of ultraviolet radiation in unprotected and sunscreen (SPF 50+) protected skin

BACKGROUND

There is a need for non-invasive biomarkers to assess in vivo efficacy of protective measures aiming at reducing ultraviolet radiation (UVR) exposure. Stratum corneum (SC) biomarkers showed to be promising markers for internal UVR dose and immune response.

PURPOSE

To establish a dose-response relationship for SC biomarkers and explore their suitability for in vivo assessment of the blocking effect of two sunscreens with a high sun protection factor (SPF) (50+).

METHODS

Twelve volunteers were exposed to a broad-spectrum UVB (280-320 nm), five times a week, during one week. Unprotected back skin was irradiated with 0.24, 0.48, 0.72 and 1.44 standard erythema dose (SED) and sunscreen-protected skin with 3.6 SED. SC samples for determination of the relative amount of cis-urocanic acid (cUCA) and thirteen immunological makers including cytokines and matrix metalloproteinases (MMP) were collected after each irradiation.

RESULTS

cUCA sharply increased after the first irradiation in a dose-dependent fashion. However, it levelled-off after subsequent exposures and reached a plateau for the highest UV-dose after the third irradiation. None of the immunological markers showed dose-dependency. However, MMP-9, IL-1β and CCL27 increased gradually from baseline during repetitive exposures to the highest UV-dose. Assessed from cUCA, both sunscreens blocked >98% of the applied UV-dose.

CONCLUSIONS

cUCA is a sensitive, non-invasive marker of the internal UVR dose enabling in vivo assessment of the blocking effect of high SPF sunscreens in the UVB-region. Immunological SC markers show low sensitivity in detecting immune response at sub-erythemal UVR dosages, suggesting they might be suitable only at higher and/or repetitive UVR exposure.

Protection Against Solar Ultraviolet Radiation in Outdoor Construction Workers: Study Protocol for a Non-randomized Controlled Intervention Study

Introduction: Non-melanoma skin cancer (NMSC) incidence is increasing, and occupational solar exposure contributes greatly to the overall lifetime ultraviolet radiation (UVR) dose. This is reflected in an excess risk of NMSC showing up to three-fold increase in outdoor workers. Risk of NMSC can be reduced if appropriate measures to reduce UVR-exposure are taken. Regular use of sunscreens showed reduced risk of NMSC. However, sun-safety behavior in outdoor workers is poor. The objective of this study is to investigate the effectiveness of an intervention aiming at increasing sunscreen use by construction workers.

Methods: This non-randomized controlled intervention study is comprised of two intervention and two control groups recruited at four different construction sites in the Netherlands. The study population comprises ~200 construction workers, aged 18 years or older, followed during 12 weeks. The intervention consists of providing dispensers with sunscreens (SPF 50+) at construction sites and regular feedback on the application achieved by continuous electronic monitoring. All groups will receive basic information on UV-exposure and skin protection. Stratum corneum (SC) samples will be collected for measurement of biomarkers to assess internal UV-dose. External UV-dose will be assessed by personal UV-sensors worn by the workers during work-shifts in both groups. To detect presence of actinic keratosis (AK) or NMSC, a skin check of body parts exposed to the sun will be performed at the end of the study. The effect of the intervention will be assessed from data on self-reported sunscreen use by means of questionnaires collected on baseline and after 12 weeks of intervention (primary outcome). Levels of SC biomarkers of internal UV-dose, external UV-dose, number of sunburn episodes, and prevalence of NMSC including AK will be assessed as secondary outcomes. The electronically monitored sunscreen consumption will be assessed as process outcome.

Discussion: This study is intended to provide evidence of the effectiveness of a technology-driven intervention to increase sunscreen use in outdoor construction workers. Furthermore, it will increase insight in the UV-protective behavior, external and internal UV-exposure, and the prevalence of NMSC, including AK, in construction workers.

Trial Registration: The Netherlands Trial Register (NTR): NL8462 Registered on March 19, 2020.

Tape stripping the stratum corneum for biomarkers of ultraviolet radiation exposure at sub-erythemal dosages: a study in human volunteers

PURPOSE

Prevalence of skin cancer is rapidly increasing. There is a need for non-invasive biomarkers to assess efficacy of prevention strategies aiming at reduction of exposure to ultraviolet radiation (UVR). Recently, stratum corneum (SC) biomarkers were applied in various inflammatory skin diseases. Here, we explore their suitability as candidate biomarkers for UVR.

MATERIAL AND METHODS

Twelve volunteers were exposed to a UVB-dose of 0.72 SED, three times a week, during three weeks. As candidate biomarkers, cis-isomers of urocanic acid (cUCA) and 25 immunological mediators were measured in the SC.

RESULTS

Eight immunological markers significantly changed from baseline. Of them, IL-1RA/IL-1α and a placental growth factor (PIGF) showed gradual changes during UVR-exposure (p < 0.01 for linear trend). cUCA increased sharply already after the first exposure, however, reached a plateau in the second week.

CONCLUSIONS

SC represents a promising, non-invasive alternative to skin biopsy in detecting UVR-induced changes. cUCA is the marker of choice for assessment of single UVR-exposure; however, it is less suitable for cumulative UVR-dose. Immunological markers including IL-1RA/IL-1α and PIGF showed gradual changes, and therefore are convenient for monitoring chronic UVR-exposure. These candidate biomarkers might facilitate assessment of the efficacy of preventive measures in the workplace and general population.

Awareness, knowledge, and attitude toward nonmelanoma skin cancer and actinic keratosis among the general population of western Saudi Arabia

Background:

This study evaluated the levels of awareness, knowledge, and attitude, including sun-protection habits, toward basal cell carcinoma and actinic keratosis among the Saudi population.

Materials and Methods:

A cross-sectional study was conducted among the general population of Jeddah, Saudi Arabia using a 12-item survey concerning the knowledge and awareness of basal cell carcinoma and actinic keratosis, as well as associated preventive measures. A Chi-square test was used to determine associations among variables.

Results:

The majority of participants were unaware of basal cell carcinoma and actinic keratosis (80.7%), while 8.6% were aware of both, and 9.8% and 1% were aware of only basal cell carcinoma or actinic keratosis, respectively. The majority of participants who were educated up to high school level had no knowledge of either condition (96%, P < 0.0001). Among participants with high levels of awareness of basal cell carcinoma and actinic keratosis, medical practitioners were identified as the main source of information (72.5%, P < 0.0001, and 70.6%, P < 0.0001, respectively). The majority of participants whose knowledge of the relationship between sun exposure and skin cancer was insufficient also lacked sufficient awareness of either basal cell carcinoma or actinic keratosis (92.6%, P < 0.0001). The majority of participants (62.8%) declared using sunscreen “rarely”.

Conclusion:

This study showed a low level of knowledge about the risks associated with sun exposure and suitable protection methods, with only a small fraction of participants declaring a regular use of sunscreen. Public education campaigns are required to increase the awareness of cancer risks and protection methods among the Saudi population.

Sunscreen Application, Safety, and Sun Protection: The Evidence

Recently in Canada, there has been an effort to create consistent messaging about sun safety as there is a lack of up-to-date evidence-based guidelines regarding sun-protection measures. This review aimed to provide updated, evidence-based recommendations on sunscreen application, safety, and sun protection regarding the following topics for which there is clinical uncertainty: physical barriers, sunscreen properties, sunscreen application, and risk-benefit analysis.

Protective effect of Arthrospira platensis extracts against ultraviolet B-induced cellular senescence through inhibition of DNA damage and matrix metalloproteinase-1 expression in human dermal fibroblasts

Ultraviolet (UV) light exposure causes skin photoaging, which is known to be preventable and controllable by application of UV-protective agents. In this study, we demonstrated, for the first time, that the extract of microalgae Arthrospira platensis has a reverse effect on UV-induced photodamage such as loss of cell viability, cellular senescence, DNA damage, and collagen destruction in dermal fibroblasts. Forty-eight extracts were prepared from the cell biomass by controlling culture light conditions, extract solvents, and disruption methods. Then, we analyzed their cytotoxicities using WST-1 assay and separated low and high cytotoxic extracts with normal human dermal fibroblasts (nHDFs). Using the low cytotoxic extracts, we performed UVB protection assay and selected the most effective extract demonstrating protective effect against UVB-induced nHDF damage. Flow cytometric analysis and senescence-associated (SA) β-galactosidase assay showed that pretreatment with the extract reversed UVB-induced G2/M phase cell cycle arrest and senescence in nHDFs. Furthermore, UVB-induced DNA damage in nHDFs, such as cyclobutane pyrimidine dimer formation, was significantly suppressed by the extract. Further, quantitative real-time PCR experiments revealed that the extract significantly inhibited UVB-induced upregulation of matrix metalloproteinase 1 (MMP1) and MMP3 expression in nHDFs. Therefore, we concluded that the microalgae extract can be a potential anti-photoaging agent.

Attitudes, Beliefs, and Measures Taken by Parents to Protect Their Children from the Sun in Guangzhou City, China

Excessive sun exposure can cause sunburn, suntan, skin photoaging, and even skin cancer. Skin photoaging conflicts with the human pursuit of a young and beautiful appearance. Some research data indicate that the incidence of skin cancer in the Chinese has been increasing, although it remains lower than in whites. To estimate the prevalence of sun protection used on Chinese children aged 3-13 years and identify its predictors, a population-based cross-sectional questionnaire was given to 3684 parents/guardians of children in Guangzhou, China, of which 3083 questionnaires were returned. Of those returned, 35.5% of parents/guardians reported regularly using sun protection on their children and the primary reason cited was to prevent sunburn. Hats and handheld umbrellas were the most frequently used measures; sunscreen was less common, and when used, 48.8% of parents/guardians still reapplied sunscreen on their children every 2.0-3.0 h. Parental age, parents using sun protection measures themselves when outdoors, and the child's sex were factors associated with regular use of sun protection on children. These results suggest that sun protection campaigns targeted toward parents and children need to be conducted in Guangzhou, or throughout China, to strengthen awareness about sun protection and address any inadequate protocols of sun protection.

Functional Food und Bioverfügbarkeit im Zielorgan Haut

Reactive free radicals can be produced in the skin by the action of environmental factors, such as sun radiation and toxins. These radicals can damage the DNA, proteins and lipids of the living cells. The consequences can be skin aging, immune suppression and even skin cancer. Humans have developed a protective mechanism against the action of free radicals in the form of antioxidant substances. Several of these antioxidants cannot be produced by humans and have to be acquired via food, such as carotenoids. Optical, non-invasive methods, like resonance Raman spectroscopy, allow a qualitative and quantitative online detection of the kinetics of antioxidants such as carotenoids in the skin. By employing this method it has been shown that the uptake of carotenoids in food can lead to an accumulation in the skin. On the other hand, stress, illness and UV-radiation can reduce the concentration of antioxidant substances in the skin. A high concentration of antioxidant substances is protective and associated with a reduction in skin wrinkling.

A broad spectrum high-SPF photostable sunscreen with a high UVA-PF can protect against cellular damage at high UV exposure doses

BACKGROUND

Advances in sunscreen technologies have yielded broad spectrum sunscreens at high-sun protection factor (SPF) and ultraviolet A protection factor (UVA-PF) levels that are photostable and powerful in protecting skin from erythema. Questions arise whether these sunscreens protect proportionally against cellular skin damage caused by high ultraviolet exposures.

OBJECTIVE

The objective of this study is to evaluate if high-SPF sunscreen can protect skin at a cellular level under UV exposure doses [>50 minimal erythema dose (MED)] similarly to the SPF value.

METHODS

Sunburn cells, Langerhans cells, thymine dimers, protein 53 (p53), and matrix metalloproteinase (MMP)-1 and MMP-9 endpoints were evaluated in biopsies from 12 subjects following four treatments: unprotected exposed to 0, 1 and 3 MED and sunscreen (SPF 55) protected exposed to 55 MED of UV radiation.

RESULTS

All the markers showed significantly more damage for the 3 MED-untreated sites when compared with non-irradiated control, and majority of the markers showed marked damage following unprotected 1 MED exposure. After 55 MEDs, sunscreen-protected sites showed significantly less p53 and MMP-9 (keratinocyte) staining than the 1 MED-exposed unprotected sites, while all the other biomarkers in sunscreen protected sites showed no statistical differences from 1 MED-exposed unprotected sites.

CONCLUSIONS

A high-SPF photostable sunscreen with high UVA-PF can provide proportionately high protection against multiple cellular damage markers.

Knowledge, attitudes and practices about sun exposure and photoprotection in outpatients attending dermatology clinics at four hospitals in Lima, Peru

BACKGROUND

To establish the knowledge, about sun exposure and photoprotection in outpatients treated at the dermatology clinics in four hospitals in Lima, Peru.

MATERIAL AND METHODS

A cross-sectional study was conducted involving a sample of 364 patients selected using a systematic random sampling process in the four participating hospitals. The selected patients were interviewed to determine their knowledge, behavior and practices in relation to sun exposure and photoprotection. The chi-square test was used to identify any significant differences between knowledge and practices.

RESULTS

The mean age of the patients in this sample was 45.1 ± 21.4 years. Of the 364 patients, 55.9% were women and 54.8% had skin phototype IV. The principal risks related to sun exposure were skin cancer (80.5%) and sunburn (77.8%). Knowledge regarding sun protection was more evident in individuals with university/college education (p<0.001). In addition, 78.9% of the individuals reported that they knew about photo-protectors and 52.3% stated that they used them regularly. In general, women were more knowledgeable regarding sun protection (p=0.001). Of the total number of users of photoprotection, 38.4% used these products daily, while 61.6% used them only occasionally. The use of photo-protectors differed significantly in accordance with the individual's education level (p<0.001). In the majority of cases there was a statistically significant difference between knowledge and practice with respect to solar protection.

CONCLUSIONS

The level of awareness of the outpatients treated at the dermatology clinics in these four hospitals in Lima, Peru about the risks of sun exposure is acceptable; however, a large proportion fail to incorporate regular solar protection as a practice in their daily life.

[Solar protection products: efficacy and risks]

Solar protection products (SPP) containing chemical filters and/or mineral filters are extensively used today in photoprotection; however, concerns continue to be voiced about their efficacy and about their possible dangers. A rapid review of photoprotection strategies shows that SPP owe their photoprotective effect to the absence of other photoprotection methods having clearly established efficacy in healthy subjects; in addition, they exhibit real protective efficacy against the majority of harmful effects of solar radiation, provided they have been devised in keeping with the specifications clearly set out in the recommendations of the French Medicines Agency (Afssaps). Such efficacy is dependent on their correct usage, recently reiterated by Afssaps in its recommendations to end-users concerning the good use of solar products: application of adequate quantities of such products, selection of the appropriate photoprotection class based on phototype and conditions of exposure, and regular renewal of applications in the event of prolonged exposure and after bathing or profuse sweating. Solar filters have long been known to cause contact allergic dermatitis, irritative dermatitis and photosensitisation, and a particular risk has appeared with the use of octocrylene. However, debate has centred primarily on the risk of endocrine disturbance potentially induced by chemical filters, certain of which exhibit established transcutaneous penetration. The risk of mimicry of an effect of oestradiol has been raised on the basis of a series of studies, almost all of which were carried out by the same team, and which mainly concerned 4-methylbenzylidene-camphor (4-MBC) following oral absorption in the rat. The risk of this type of effect with SPPs under normal conditions of use seems fairly remote according to the current state of knowledge; in any event, within the context of the "National Fertility Action Plan", Afssaps has been formally requested to analyse the risk associated with cosmetic substances that are "reprotoxic" and/or affect endocrine function, as a result of which various filters are currently being reassessed for such risk. The greater alleged safety of mineral filters, based on the absence of introduction of risk of photosensitisation (as a result of which they are preferred for use in young children), no longer seems so clear since the introduction of titanium dioxide (TiO2) and zinc oxide (ZnO) in the form of nanoparticles. Afssaps drew up a risk assessment report concerning cutaneous penetration, genotoxicity and oncogenesis for TiO(2) and ZnO in nanoparticle form; further studies are needed before any general conclusions may be drawn. The European Scientific Committee on Consumer Safety (SCCS) is also carrying out an evaluation of the use of TiO(2) and of ZnO as UV filters. Finally, current data do not suggest that SPPs exert any harmful effects by inhibiting the beneficial effects of the sun, in particular, vitamin D synthesis.

Sun-exposure knowledge and protection behavior in a North Chinese population: a questionnaire-based study

BACKGROUND

Sun exposure can cause a range of skin disorders. Skin damage can be prevented by following certain sun-protection measures. However, the majority of reported studies regarding sun-exposure knowledge and behavior have involved Caucasian populations.

METHODS

A self-administered multiple-choice questionnaire was administered. The questionnaire consisted of 13 questions aimed at evaluating people's knowledge, awareness, and protection behavior regarding sun exposure, and their knowledge of sunscreens and sunscreen use.

RESULTS

A total of 623 volunteers were enrolled, including 238 men (38.2%) and 385 women (61.8%). The percentages of correct answers regarding sun-exposure knowledge and awareness ranged from 50% to 80%. Overall, 58.8% used sunscreen as a sun-protection measure in daily life, followed by use of protective clothes (49.3%), sun umbrella (45.4%), sunglasses (45.3%), and hat (42.2%). Fifty-two percent thought that suntan was harmful or not attractive. The mean sun-protection factor (SPF) of the sunscreens used was 27.7 +/- 9.2 and the mean UVA protection grade (PA) was 2.3 +/- 0.6.

CONCLUSIONS

Knowledge and awareness concerning the harmful effects of sun exposure are widespread among the Chinese population. Sunscreens with high SPF and PA are the most commonly used among Chinese people. Clear sex differences were observed. There is a significant difference in the attitude toward suntan between Chinese and Caucasian populations.

Update on sun protection and tanning in children

PURPOSE OF REVIEW

In this article we examine the latest information regarding pediatric sun protection and specifically focus on the impact of indoor tanning on children.

RECENT FINDINGS

We examine and discuss the prevailing views and trends on ultraviolet radiation exposure, sun protection and the attendant adverse health effects among children. We identify the challenges related to limiting ambient ultraviolet exposure in children. As children, particularly adolescents, gain an understanding of sun protection, their use of ultraviolet radiation protection does not increase concordantly. We discuss health policies regarding ultraviolet radiation protection, compliance with these policies and potential methods to increase compliance. We also examine addiction-like behavior and other psychosocial factors affecting those who are regular indoor tanners. Finally, we consider possible alternatives to ultraviolet radiation induced tanning and whether encouraging these options leads to a confusing, mixed message from healthcare providers.

SUMMARY

In this article we examine and discuss current practices, attitudes and recent trends in sun protection. We discuss indoor tanning, with special emphasis on the potential addictive qualities of ultraviolet radiation. Our goal is to identify opportunities and future directions to promote sun safety and protect children from harmful ultraviolet radiation exposure.

Sunscreen Product Formulation

On the surface, sunscreen products are pretty simple. They consist of a delivery vehicle containing one or more sunscreen active ingredients. When applied to the skin, these sunscreen actives intercept solar ultraviolet (UV) rays before they can damage the underlying skin. However, while conceptually simple, a detailed analysis reveals that sunscreen formulations are quite complex, requiring careful selection of sunscreen active and vehicle components to control multiple performance and in-use parameters.Thus, to enable a better understanding and appreciation of sunscreen products, the typical steps in formulating a sunscreen product are described. Throughout this process, the key is to apply scientific principles together with a bit of formulation art to holistically create the best sunscreen product that meets the design targets--a sunscreen product that people will use regularly and properly.

Photoprotection in adolescence

Physical changes and the establishment of personal values are characteristics of adolescence. Despite being well informed regarding sun protection and the skin cancer risks related to sun exposure, teenagers usually make little use of sunscreens and remain out in the sun for long periods. Besides the social appeal and the impression that a nice tan provides a healthy appearance, the tendency to deny long-term risks seems to influence sun exposure behaviors in this life period. Due to the strong relation between skin cancer and sun exposure in childhood and adolescence, it is important to encourage the adoption of photoprotection measures early in life. Adolescents have difficulty accepting guidance through official educational messages, and very few of them follow family recommendations. Celebrities, fashion, and the entertainment industry exert a greater influence on their choices. Thus, it is fundamental to incorporate photoprotection counseling into the medical routine, in an adolescent-driven way. This article reviews peculiarities of sun protection in adolescence and discusses the type of advice to be given to patients in this age group.

Photoprotection

Many agents affect the transmission of ultraviolet light to human skin. These include naturally occurring photoprotective agents (ozone, pollutants, clouds, and fog), naturally occurring biologic agents (epidermal chromophores), physical photoprotective agents (clothing, hats, make-ups, sunglasses, and window glass), and ultraviolet light filters (sunscreen ingredients and sunless tanning agents). In addition, there are agents that can modulate the effects of ultraviolet light on the skin (antioxidants and others). All of the above are reviewed in this article.

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should be able to provide an overview of all aspects of photoprotection.

Awareness, knowledge and attitudes to non-melanoma skin cancer and actinic keratosis among the general public

BACKGROUND

The incidence of nonmelanoma skin cancer (NMSC) has dramatically increased worldwide. In areas of high incidence this will place a significant burden on the health system. Objectives To establish the awareness, knowledge and attitudes of the general public to NMSC and provide an overview on their level of understanding and knowledge of preventative measures.

METHODS

Two thousand and one hundred Caucasian and Hispanic individuals, aged 40-75 years, from the UK, Italy, Germany, Spain, France, the USA and Australia were randomly selected to participate in this market research survey. In a structured telephone interview lasting approximately 10 min, respondents answered questions on NMSC, specifically actinic keratosis (AK) and basal cell carcinoma (BCC).

RESULTS

Overall, 6% of respondents had been diagnosed with NMSC, of which the incidence was highest in Australia and the USA. The frequency of skin cancer detection examinations was also greater within these populations. Countries with a high incidence of NSMC had greater awareness of the condition, with more awareness of BCC than AK. The majority of respondents believed there was a correlation between skin cancer and sun exposure, however, a minority of respondents associated skin cancer with 'moderate' tanning. Overall, 86% of respondents claimed that they always took precautions against ultraviolet exposure when in the sun, but only 26% applied sunscreen most or all of the time when they were exposed to the sun for more than 1 h. In most of the countries, outside workers reported lower sunscreen use than other respondents.

CONCLUSION

Nonmelanoma skin cancer awareness and prevention behaviors varied significantly among the countries studied. Improved population-specific documentation of skin cancer knowledge and prevention behaviors will facilitate the development and assessment of public health campaigns.

Awareness, knowledge and attitudes to basal cell carcinoma and actinic keratoses among the general public within Europe

OBJECTIVE

As the incidence of non-melanoma skin cancer (NMSC) is reported to be increasing in Europe, the objective of this survey was to establish the general population's awareness and knowledge of basal cell carcinoma (BCC) and actinic keratoses (AK) within five European countries.

METHODS

A total of 1500 individuals from the United Kingdom, France, Italy, Germany and Spain were randomly selected to participate in the study. In a 10-minute structured telephone interview respondents answered questions on skin cancer and BCC and AK.

RESULTS

Overall, 46% of respondents were concerned about skin cancer. Even though the majority of respondents believed there was a correlation between skin cancer and the sun or overexposure to sunlight, nearly a third of the surveyed population rarely or never used sunscreen when outdoors. In general there was a low level of awareness about BCC and AK, with only 22% and 6% of respondents, respectively, being aware of the conditions.

CONCLUSION

There is a need to increase the awareness of skin cancer and safe sun practices among the European population.

Sunscreen application at the beach

BACKGROUND

The sun protection factor (SPF) of sunscreens is determined after application of a standard amount. The European Cosmetic Toiletry and Perfumery Association (COLIPA) standard amount is 2 mg/cm(2). Real-life application of sunscreen is probably less than this.

AIM

To determine the amount of sunscreen present on the skin of people at the beach.

METHODS

Volunteers at the beach were selected randomly and were not aware of being tested for the adequacy of their sunscreen application. All volunteers had applied sunscreen. Application had been more than 30 min before testing (sometimes up to 4 h earlier). The amounts of sunscreen applied to different body sites were determined quantitatively by tape stripping. Actual amounts of sunscreen applied were compared with the COLIPA standard. Also, sunscreen containing a fluorescent dye was applied to the skin of volunteers in a laboratory setting. The distribution of sunscreen application was visualized by UVA photography in a darkened room.

RESULTS

Sixty volunteers, 33 males and 27 females, aged 17-68 years (median 32 years), were recruited at the beach. Sunscreen coverage was inadequate at all body sites. Coverage at various body sites differed greatly. Most volunteers had applied 10% or less of the COLIPA standard amount to all body sites assessed. The best protected areas were the upper arm and décolleté but, even in these areas, most volunteers had only applied 10% of the COLIPA standard amount. The worst protected areas were the ears and top of the feet. The back was typically badly protected if treated by the volunteers themselves. The back was better protected if another person had applied the sunscreen. In the laboratory, the fluorescent dye-containing sunscreen showed the same pattern of sunscreen application as at the beach.

CONCLUSIONS

In real life, at the beach, very little sunscreen remains present on the skin.

Practical and experimental consideration of sun protection in dermatology

Much is known regarding the deleterious effects of ultraviolet radiation (UV) on the skin. As more epidemiologic and basic research continues to characterize the impact of sun exposure and other sources of UV radiation upon the development of cutaneous neoplasm and a variety of photosensitive dermatoses, it is crucial for the dermatologist to promote sun protection among his/her patients as well as the primary care physician who has a greater reach of the community than the skin specialist. Practical steps to achieve optimal sun protection include avoidance of UV radiation, avoidance of photosensitizing drugs, use of photo-protective clothing, and diligent application of broad-spectrum sunscreens. In recent years, novel agents and experimental modalities with the potential to offer enhanced protective effects against deleterious sequelae of sun exposure have been elucidated, e.g. antioxidants, alpha-MSH, polyphenol in green teas, genistein, NF-kB decoy oligodeoxynucleotides, pTpT vaccination, and IL-12. As these new photo-protective tools are being developed by scientists around the world, greater concerted effort is needed to engage public health officials and the media to promote sun protection awareness throughout the general public.

Modulations of nerve growth factor and Bcl-2 in ultraviolet-irradiated human epidermis

BACKGROUND

Ultraviolet (UV) irradiation to the skin causes apoptosis of keratinocytes. Melanocytes are more resistant to UV-induced apoptosis, due, in part, to high levels of antiapoptotic proteins such as Bcl-2. In vitro studies have shown that nerve growth factor (NGF), a neurotrophic polypeptide, is produced by keratinocytes and exerts a protective role for melanocytes by upregulating Bcl-2. The purpose of this study was to determine NGF and Bcl-2 modulations in UV-irradiated human skin.

METHODS

Nine volunteers were irradiated with two minimal erythema doses using solar-simulated UV irradiation. Seventy-two hours post irradiation, skin biopsies were obtained from irradiated and sun-protected skin. The skin specimens were stained with anti-tyrosinase-related protein-1 monoclonal antibody IgG2a (Mel-5), anti-Bcl-2 (monoclonal antibody IgG-kappa), and with anti-NGF (polyclonal antibody IgG).

RESULTS

NGF staining was identified within the cytoplasm of epidermal melanocytes, similar to the staining observed for TRP-1 and Bcl-2. While no significant difference in the number of TRP-1- and Bcl-2-positive melanocytes was observed between irradiated and non-irradiated skin within 72 h, the number of NGF-positive melanocytes decreased significantly, 72 h after UV irradiation (p < 0.024). NGF was also identified within keratinocytes, and while non-irradiated skin exhibited cytoplasmic NGF staining throughout the epidermis, NGF staining was reduced in the lower epidermal layers after UV irradiation.

CONCLUSIONS

This is the first in vivo study showing NGF to be present in melanocytes, as well as showing modulations of NGF and Bcl-2 in melanocytes, following solar-simulated UV irradiation.

Local therapy for cutaneous and systemic lupus erythematosus: practical and theoretical considerations

Local therapeutic measures should be maximized in the management of lupus erythematosus (LE), particularly for patients with forms of LE-specific skin disease such as SCLE and CCLE. Local therapy consists of sun protection and locally-applied pharmacologic agents, e.g. topical/intralesional corticosteroids. Patients should be advised to avoid direct sun exposure, wear lightweight tightly woven clothing and broad-brimmed hats, and use broad-spectrum, water-resistant sunscreens. There are several modalities that enhance permeability of local therapeutics through the stratum corneum that could be applied to topical therapy of cutaneous LE, e.g. polar solvent, liposomal encapsulation, ethosomal system, iontophoresis, electroporation and sonophoresis. As novel and more effective modalities to deliver pharmacologic agents across the stratum corneum become available, therapeutics that have been experimental and untested thus far may become part of the local armamentarium in the near future. In addition, physical/contact therapy as well as dermatosurgical methods can be invaluable in enhancing self-image and quality of life of patients with disfiguring cutaneous LE lesions.