Sunscreen Sun Protection Factor Research Articles

A Summarized Review of Formulation, in Vitro Evaluation of Sunscreen

The efficacy and safety of sunscreens are diminished when their agents permeate the skin, resulting in systemic circulation and unidentified negative effects. The filters in sunscreens muster main on the skin's surface with minimal penetration through the dermis in order to preserve their safety and efficacy. Sunscreen should always be worn, even in the event that filters manage get through. Damage like as erythema, the production of free radicals, aging of the skin, and skin cancer brought on by UV radiation. Research is being done to limit skin penetration, assess sun protection factor (SPF), and improve formulation properties and stability in order to target potential negative effects caused by topical absorption of sunscreens. In vitro or in vivo investigations are used in current assays to determine sunscreen penetration since they mimic the physiological conditions of use. This review objectives are to reexamine data on sunscreen skin penetration over the last ten years and identify variables that may increase skin penetration or boost sunscreen efficacy. Sunburn is caused by ultraviolet B radiation, but ultraviolet A may be more damaging to the skin. Sunscreens should ideally block both wavebands. A sunscreen sun protection factor is mostly determined by how well it blocks ultraviolet B. The efficiency of preventing ultraviolet A is not measured. Sunscreens may be organic or inorganic chemicals. If metal oxide sunscreens are made into nanoparticles, their cosmetic acceptance might increase. It doesn’t seem that absorbing organic sunscreens and nanoparticles has any appreciable systemic effects. Frequent use of sunscreen prevents melanoma, squamous cell carcinoma, and actinic keratosis from developing.

Fabrication of CeO2/CaO nanocomposite as ultraviolet screening agent and its application in sunscreen

In order to improve CeO2 ultraviolet absorption performance and transparency, this paper puts forward that different proportions of calcium oxide are doped during the formation of CeO2. Doping calcium ions with larger ion size and lower valence leads to the formation of oxygen defects by inhibiting the precipitation of oxygen from cerium oxide and keeps the fluorite structure of cerium oxide stable. The effects of CaO doping on the crystal structure, morphology, and optical characteristics of CeO2 were analyzed by XRD, SEM, TEM, TGA, XPS, UV–vis spectrophotometry. The pH of sunscreen, spread ability and some physical as well as chemical evaluations were carried out, while to study its UV protection performance the sunscreen SPF test was performed. The UV–vis results revealed that CeO2/20%CaO showed highly efficient UV absorption capacity. After adding calcium oxide, the catalytic activity of the material is reduced, due to which the generation of free radicals is demoted, and the harm to human body is decreased. After the addition of 3 wt% nanomaterials into sunscreen, the sun protection factor（SPF ）values of pure cerium oxide and CeO2/20%CaO are 1.95 and 2.81, and their sun protection coefficient is increased by 69.39%. Therefore, it is an ideal candidate as a component of ultraviolet screening agent in sunscreens and provides a new idea for the research direction of cerium oxide in anti-ultraviolet applications.

The PENGARUH PENAMBAHAN EKSTRAK DAUN MANGGA MANALAGI TERHADAP MUTU FISIK DAN EFEKTIVITAS TABIR SURYA EMULGEL KOMBINASI OCTINOXATE-AVOBENZONE

Avobenzone and octinoxate are often used as a combination of organic UV filters in sunscreen. At high exposure to UV light, these UV filters can be degraded so that their sunscreen’s effectiveness is reduced. Several studies reported that the combination of plant extracts with synthetic UV filters could increase sunscreen's SPF. Mango leaves contain high levels of flavonoids and in several studies have been shown to have photoprotective activity with good Sun Protection Factor (SPF) values. The Manalagi mango plant is a type of mango that is widely planted in yards, so it's easy to get the raw materials. This study aims to determine the effect of manalagi mango leaf extract with a concentration of 1, 3, and 5% on the physical quality (pH, viscosity, spreadability) and sunscreen activity (SPF, %TE, %TP) of sunscreen emulgel containing avobenzone and octinoxate. This study showes that increasing the concentration of manalagi mango leaf extract reduced the pH and viscosity of the preparation, and significantly increased the spreadability of all formulas. Besides that, it can also increase the SPF value and decrease the %TE and %TP values. The emulgel formula that had the highest sunscreen activity was F3 with an extract concentration of 5%, had an SPF value of 30.597 ± 0.600, %TE 0.0001 ± 0.0001, and %TP 0.0038 ± 0.0016.

Assessment of the SPF and Anti-Irritating Properties of Sunscreen designed for Retinol users

Vitamin A and its derivatives, also known as retinoids, when applied topically for anti-ageing benefits, typically cause erythema and dryness on the skin, which are considered significant and common side effects. Furthermore, users of topical retinoids, like everyone else, need a sunscreen that protects the skin from harmful sun exposure while simultaneously countering the erythema and dryness of the skin. Retinoids also enhance the rate of skin cell turnover and expose newly produced skin to solar exposure, increasing the risk of sun damage and hyperpigmentation. Since the skin becomes sensitive with topical retinoids, a sunscreen must possess the further benefit of elevated skin resilience, which is much needed with conventional sun protection. ‘‘EI Pro Retinol Sunscreen’’ came up with a new innovative sunscreen with UV protectants and other active ingredients that have calming and soothing properties that minimize erythema and dryness. EI launched the “EI PRO Retinol series,” which includes the “EI PRO Retinol Sunscreen,” to protect the skin from the detrimental effects of ultraviolet rays as well as further irritation and itching caused by retinoid actions on the skin. In this study, researchers attempted to develop and design a sunscreen using a patented sunscreen agent (a combination of water, ethylhexyl methoxy-cinnamate, butyl methoxy-dibenzoyl-methane, benzophenone-3, phospholipids, and 1,3-butylene glycol) and Porphyridium cruentum (marine algae) for skin resilience, antioxidants like ascorbic acid, vitamin E, and soothing agents like carrot seed oil and sodium hyaluronate. Sunscreens are evaluated based on their sun protection factor (SPF), PA rating, and critical wavelength. Usually, sunscreens with an SPF above 50, a PA rating of ++++, and a critical wavelength over 370 nm would offer higher sun protection and block both UVA and UVB rays. The results showed that “EI PRO Retinol Sunscreen” has a critical wavelength of 376.67 and is considered a broad-spectrum SPF 50 PA++++ sunscreen. Thus, ‘‘EI PRO Retinol Sunscreen’’ is also proven to be safe on the skin without irritation, and it is proven to be non-irritant by a single, blinded patch test method.

The Comparison of Sun Protection Factor 30 Persistence Between Inorganic and Organic Sunscreen in Swimmers: Double-blind Randomized Clinical Trial.

Long-term sun exposure is one of the risks faced by outdoor swimmers and can cause sunburn. Using sunscreen is one way to prevent sunburn; however, physical activity can trigger sweat, friction, and water washing that can interfere with sunscreen efficacy and decrease its sun protection factor (SPF). Sunscreens are classified into inorganic and organic based on their filter. Organic sunscreen has a better bond to the skin than inorganic sunscreen, which forms a barrier above the skin layer that makes removing it easier. Organic sunscreen lasts longer than inorganic sunscreen when used in physical activities, but it has a limited spectrum, is more photolabile, and is more allergenic. This study aims to evaluate the persistency of SPF 30 between inorganic and organic sunscreens on the back area after 1.5 hours of swimming. This study is a randomized, split-body, double-blind clinical trial to evaluate the persistency of SPF 30 of the inorganic versus organic sunscreens in swimmers. Randomization was done to allocate the participants into treatment groups. Each participant received inorganic and organic sunscreen treatments applied to the back area. The research participants were swimmers from the Cikini swimming pool and Bina Taruna swimming pool, both in Jakarta, Indonesia. A total of 22 swimmers were enrolled in this study. The analysis showed no significant difference between the SPF of the two sunscreens before swimming (P=.22). After swimming, the SPF levels of both sunscreens decreased: the inorganic sunscreen decreased from a median of 27 (range 23-47) to 12.3 (range 8-19), and the organic sunscreen decreased from a median of 30 (range 24-47) to 9.9 (range 6-19), which was statistically significant (P<.001). When comparing the SPF of inorganic and organic sunscreens after swimming, there was a statistically significant difference in the decrease in SPF levels between the two groups (P=.02), which indicated a better SPF persistence for inorganic sunscreens when compared to organic sunscreens. There was a decrease in the SPF levels of inorganic and organic sunscreens after 1.5 hours of swimming, with better persistence in inorganic sunscreens compared to organic sunscreens. ClinicalTrials.gov NCT04618536; https://clinicaltrials.gov/ct2/show/NCT04618536. RR2-10.2196/42504.

Designing a Band for Vehicles' Drivers Induced by Ultraviolet and Infrared Radiations.

Solar radiations that reach the Earth can be divided into ultraviolet, visible light, and infrared. Overexposure to these radiations can facilitate adverse skin diseases such as sunburn, skin cancer, and photoaging. People who drive vehicles for an extended period are likely to develop skin cancer in the exposed body area. This research proposes a wearable protective device around the upper arm to measure the transmitted radiation through the front and the side windows. A novel skin type classification algorithm using a color sensor was created to provide an accurate skin type identification. Also, the device was programmed to calculate the time before sunburn occurrence based on the ultraviolet index, sunscreen's sun protection factor, and skin type. The prototype was tested inside a Toyota Camry model 2001 vehicle with an accuracy of 97%. The front window had transmitted more infrared radiation compared to the side window. The highest recorded value was 76.76 mW/cm2. On the other hand, the side window had transmitted more ultraviolet compared to the front window as it lacks the protective polyvinyl butyral layer that the front window has. The highest recorded ultraviolet index was 3.5. These results highlight the importance of wearing the designed solar band and using appropriate UV and IR protection while driving a vehicle to prevent skin diseases from occurring.

Characteristics, Antioxidant Activity, and Sun Protection Factor of Black Pomegranate Peel Ethanolic Extract Hydrogel

Solar UV radiation can inactivate the SARS-CoV-2 virus and indirectly accelerate the recovery rate of Covid-19 patients by converting pro-vitamin D3 in the skin into pre-vitamin D. On the other hand, prolonged exposure to UV radiation might be harmful to skin health, making it necessary to use sunscreen. Synthetic chemical sunscreens can have adverse side effects, and alternatives utilizing natural ingredients are needed. The peel of the black pomegranate has strong antioxidant properties and it also has the potential as a sunscreen by making it into a topical hydrogel preparation. The purpose of this study was to examine the characteristics, antioxidant activity, and sun protection factor (SPF) capacity of the ethanol extract of black pomegranate peel hydrogel preparations. Hydrogel was created containing black pomegranate peel ethanolic extract at concentrations of 0.5%, 1.0%, and 1.5%. Then, the characteristic properties were determined, the antioxidant power was examined using DPPH (2,2′-diphenyl-1-picrylhydrazyl radical) assay, and the SPF was investigated by the spectrophotometry method. The hydrogel containing extracts of 0.5%, 1.0%, and 1.5% had characteristics that fulfilled the specified requirements, having an inhibition percentage of 27.39%, 54.90%, and 83.91%, respectively, at the sample concentration of 600 ppm, and the SPF of this hydrogel was 2.67, 4.36, and 6.65, respectively. Therefore, according to the findings, hydrogel of black pomegranate peel ethanolic extract is good as a topical antioxidant but is less effective as SPF sunscreen.&#x0D; Keywords: antioxidant, hydrogel, SPF, black pomegranate peel ethanolic extarct

Sunscreen-using U.S. adults are using higher sun protection factor sunscreens: Data from the National Health Interview Survey 2005-2015

To the Editor: Sunscreen reduces skin cancer, sunburn, and photo-aging risks, with higher sun protection factor (SPF) values providing enhanced protection.1 The American Academy of Dermatology recommends broad-spectrum sunscreens with SPF ≥30.2 We investigated temporal trends of SPF among sunscreen users to determine consumer preference changes over time.

Characteristics and common ultraviolet filter usage of sunscreens purchased online: Cross-cultural analysis across 5 continents.

A wide range of sunscreen products are available globally. Designed to meet various customer needs, they differ in formulations type, textures, ingredients, ultraviolet (UV) protection capabilities, and other properties. Knowing the factors influencing the purchase of sunscreens and the UV filters commonly used in each global region would be beneficial for dermatologists, consumers, and regulators. Data on 50 best-selling sunscreens from each of 20 countries on 5 continents (1000 products in all) were retrieved from Amazon Marketplace during the period from January to July 2021. Among the 5 continents, Asia had the highest proportion of consumers (71.1%) choosing high sun protection factor (SPF) sunscreens (SPF ≥50). In contrast, Europe had the highest percentage (11.8%) purchasing <30 SPF sunscreens. The lack of standard UVA protection labeling was significantly highest in South America. The use of inorganic-based sunscreen was highest in North America, and across all continents, those products were significantly more expensive than organic-based sunscreens. Globally, lotions were the most favored formulation type. "Nongreasy/dry touch" (45.1%) and "lightweight texture" (40.4%) were the most common promotional terms used. The most common UV filters differed among regions. Iron oxide, which can function as a visible light filter, was most frequently found in sunscreens in South America (20%) and North America (19.3%). The regional factors influencing the purchase of sunscreen products differed. A considerable number of sunscreens may not provide adequate sun protection for consumers. Dermatologists should recommend sunscreens with sufficient UV protection that suit the skin of individual consumers.

Evaluation of the, in vitro, photoprotetive capacity of Moringa oleifera oil for its use in sunscreen formulation

Moringa oleifera Lam is an Indian plant with applications in the agricultural and medical fields. The assets development capable of increasing the efficiency of sunscreens, mainly those of plant origin, due to their natural benefits, represents an increasing demand for cosmetology. The present study aims to identify by CG-MS the constituents of the most active oil and to evaluate the photoprotective capacity of Moringa oil, and its action in sunscreen formulations. Extracts of the oils from the Moringa seeds were evaluated for the Sun Protection Factor (SPF) observing the highest result for the dichloromethane extract. This extract showed low cytotoxic potential for human fibroblasts and it was incorporated into a sunscreen. The extract increased the SPF of the sunscreen and its effect may be related to fatty acids identified by GC-MS. The results showed the benefit of Moringa oil as a vegetable active in the sunscreen formulations by increasing the SPF of sunscreens in a natural and sustainable way.

Multi-laboratory study of hybrid diffuse reflectance spectroscopy to assess sunscreen SPF and UVA-PFs.

Proof-of-principle studies have established the use of Hybrid Diffuse Reflectance Spectroscopy (HDRS) methods to assess both Ultraviolet-A Protection Factor (UVA-PF) and Sun Protection Factor (SPF) indices in individual laboratories. Multiple laboratories evaluated 23 emulsions and two spray sunscreen products to evaluate repeatability and accuracy of assessment of SPF and UVA-PF values, using HDRS test systems from various manufacturers using different designs. All of the laboratories reported similar SPF and UVA-PF values within a narrow range of values to establish the reliability of the HDRS methodology across laboratories, independent of equipment manufacturer or operator. HDRS test methodology provides a reliable objective instrumental estimation of sunscreen SPF and UVA-PF. These data were provided to ISO-TC217 WG7 to substantiate the ongoing development of an ISO Standard HDRS Method.

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

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. 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+). Twelve volunteers were exposed to a broad-spectrum UVB (280-320nm), 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. 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. 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.

The sun is here! What will you recommend?

Spring and summer are just around the corner, and most areas accustomed to clouds and cooler temperatures will begin to experience a warming trend. This means folks will be spending more time in the sun. Pharmacists should be prepared to answer questions and make recommendations about sunscreen. Here's some important information to consider as you counsel patients on sun safety and the benefits of using sunscreen. The ultraviolet (UV) spectrum is divided into three major bands—ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC)—all of which may cause or exacerbate sun-induced skin disorders. UVA and UVB primarily are responsible for photodamage, as all UVC radiation is removed by the ozone layer. UVA and UVB both play a role in causing skin cancer. The only true therapeutic effect of UVB exposure is synthesis of vitamin D3 in the skin. Sun protection factor (SPF) is one parameter for determining a sunscreen's effectiveness for UV protection. Another parameter, minimal erythema dose, is used to calculate a sunscreen's SPF. SPF is calculated based on the time to skin burning with sunscreen compared with time to skin burning without sunscreen. For example, by using SPF 10, a person who usually stays in the sun for 10 minutes before starting to burn can prolong that time to approximately 100 minutes. Many dermatologists recommend using a product with SPF 30 or higher. Topical sunscreens can be divided into two major subgroups: chemical and physical. Chemical sunscreens absorb and thus block the transmission of UV radiation to the epidermis. Physical sunscreens are generally opaque; instead of absorbing UVR, they reflect and scatter it. Broad-spectrum sunscreens are designed to protect against both UVA and UVB rays. Many medications are associated with photosensitivity reactions. Review your patient's medication list and counsel patients to prevent any negative reactions. ▪For maximum effectiveness, apply sunscreens liberally to all sun-exposed areas of the body and reapply at least as often as the label recommends.▪Apply to dry skin at least 15 to 30 minutes before sun exposure if expecting to spend more than 20 minutes in the sun.▪Reapply every 2 hours at minimum, even on cloudy days.▪Reapply after heavy sweating, swimming, and toweling off. Reapplying doesn’t extend the length of time a person is protected from sunburn.▪When using sunscreen sprays, spray and rub into skin to ensure uniform coverage.▪If using insect repellent and sunscreen, apply sunscreen before insect repellent.▪Do not use on children younger than 6 months. Lotions are the preferred dosage form for children.▪For sufficient protection, the average adult in a bathing suit should apply nine portions of sunscreen of approximately ½ teaspoon each, or approximately 4.5 teaspoons (22.5 mL) total. Distribute the sunscreen as follows:–Face and neck (including ears): ½ teaspoon–Arms and shoulders: ½ teaspoon to each side of body–Torso: ½ teaspoon each to front and back–Legs and tops of feet: 1 teaspoon to each side of body As we consider the opportunities to counsel patients on appropriate sunscreen use, we shouldn’t assume they’re getting this advice elsewhere. Many people believe they’re knowledgeable about sunscreens and protection from the sun's harmful rays—until they get a sunburn. Because of the cost of sunscreen products and the need to apply them often and in sufficient amounts, users may apply substantially less sunscreen than is required to provide adequate protection. Find ways to educate your patients on optimal ways to protect against the potential dangers of the sun's UVA and UVB rays while still enjoying outdoor fun and activities. Shelf talkers and signage in the appropriate OTC sections of the pharmacy can facilitate dialogue. And don’t forget to practice what you preach!

SCAN! A pharmacy-based, sun safety feasibility study

ObjectivesSkin cancer is the most common form of cancer, and individuals from the medically underserved Appalachian region are at elevated risks for cancer morbidity and mortality. Skin cancer can be prevented by decreasing ultraviolet light exposure (sunscreen sun protection factor 30, shade, clothing, sunglasses, hats) and can be caught at an early treatable stage through a routine skin examination. The Skin Cancer Awareness Now! (SCAN!) pilot project promoted skin cancer prevention and screening in community pharmacies, using a dynamic communication model. The objectives of the study were to understand (1) the feasibility of the SCAN! and (2) the preliminary impact of the SCAN! MethodsWe conducted pre- and postintervention surveys of the SCAN!, a student pharmacist–led or pharmacy resident–led intervention in community pharmacies (n = 3). ResultsParticipants (n = 90) had a mean age of 43.8 (SD= 18.4) years, were predominantly white (92.1%), without a college degree (65.6%), and had an average family income in the range of $25,000-$49,999, with approximately 16% falling below the poverty level. To begin, the SCAN! scored highly in attention (mean = 5.8), liking (mean = 6.1), comprehension (mean = 6.7), and intentions to be sun safe (mean = 6.0). Most improved in their knowledge of the amount of sunscreen needed per application for sun safety (66%, P < 0.01) and of melanoma features from pre- and postintervention (39%, P < 0.01). A multivariate analysis of variance indicated that knowledge and intentions improved (all P’s < 0.01). Interaction effects indicated that improvements in knowledge were greater for those in the rural pharmacy (P = 0.03), and improvements in perceived importance were greater for those in urban pharmacies (P = 0.01). ConclusionThe SCAN! intervention was well received by the population. Our study provides evidence that community pharmacy is a novel venue for skin cancer prevention interventions, particularly for rural, medically underserved populations.

Prospective of Monascus Pigments as an Additive to Commercial Sunscreens

Red and yellow pigments from Monascus purpureus (NMCC-PF01) were evaluated to enhance sun protection factor (SPF) of commercial sunscreens and Aloe vera extract. The extracted Monascus pigments contain rubropunctamine (red pigment) and the mixture of monascin and ankaflavin (yellow pigment) as major components. Antioxidant activity and in-vitro safety of the pigments were assessed by ferric reduction potential and DPPH radical scavenging assays, human keratinocytes (HaCaT), and erythrocytes (RBCs) cytotoxicity assay, respectively. In results, SPF of commercial sunscreens showed an increase of 36.5% with red pigment compared to the 13% increase by yellow pigment. The in-vitro studies showed 67.6% ferric reducing potential and 27% DPPH radical scavenging activity, neither cytotoxic effect against human keratinocytes nor haemolytic activity. These results confirmed the safe nature of the Monascus pigments; however, in-vivo studies merit further research. In conclusion, screened pigments from Monascus purpureus may act as potential candidates to increase SPF of commercial sunscreen naturally.

The effect of sunscreen on vitamin D: a review.

Sunscreen use can prevent skin cancer, but there are concerns that it may increase the risk of vitamin D deficiency. We aimed to review the literature to investigate associations between sunscreen use and vitamin D3 or 25 hydroxyvitamin D [25(OH)D] concentration. We systematically reviewed the literature following the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. We identified manuscripts published in English between 1970 and 21 November 2017. Eligible studies were experimental [using an artificial ultraviolet radiation (UVR) source], field trials or observational studies. The results of each of the experimental studies and field trials are described in detail. Two authors extracted information from observational studies, and applied quality scoring criteria that were developed specifically for this question. These have been synthesized qualitatively. We included four experimental studies, three field trials (two were randomized controlled trials) and 69 observational studies. In the experimental studies sunscreen use considerably abrogated the vitamin D3 or 25(OH)D production induced by exposure to artificially generated UVR. The randomized controlled field trials found no effect of daily sunscreen application, but the sunscreens used had moderate protection [sun protection factor SPF) ~16]. The observational studies mostly found no association or that self-reported sunscreen use was associated with higher 25(OH)D concentration. There is little evidence that sunscreen decreases 25(OH)D concentration when used in real-life settings, suggesting that concerns about vitamin D should not negate skin cancer prevention advice. However, there have been no trials of the high-SPF sunscreens that are now widely recommended. What's already known about this topic? Previous experimental studies suggest that sunscreen can block vitamin D production in the skin but use artificially generated ultraviolet radiation with a spectral output unlike that seen in terrestrial sunlight. Nonsystematic reviews of observational studies suggest that use in real life does not cause vitamin D deficiency. What does this study add? This study systematically reviewed all experimental studies, field trials and observational studies for the first time. While the experimental studies support the theoretical risk that sunscreen use may affect vitamin D, the weight of evidence from field trials and observational studies suggests that the risk is low. We highlight the lack of adequate evidence regarding use of the very high sun protection factor sunscreens that are now recommended and widely used.

573 Effectiveness of methods for sunscreen application counseling

Reduced UV exposure is critical for primary and secondary prevention of skin cancers. Sunscreen use is a common strategy for sun protection, but effective usage by high-risk individuals can remain elusive; there are numerous barriers to applying the recommended application amount. We found that 74% of patients indicated that the amount of sunscreen applied is important for the amount of protection, but >50% were unaware of guidelines for estimating application amounts. We compared the effectiveness of sunscreen-use counseling via a handout vs. in-person counseling vs. no intervention, by quantitating the amount (mass) of sunscreen applied before and after interventions for 252 patients. In person-counseling included a demonstration of the recommended amounts of sunscreen to be applied to the face or arm, using the patient’s own sunscreen. Amounts were benchmarked to the Teaspoon Rule, to achieve protection corresponding to the sunscreen's sun protection factor (SPF). A handout was not more effective than no intervention (p=0.31), however men appeared to derive benefit from a handout, women did not. In-person counseling was significantly more effective than a handout and resulted in the recommended amount of sunscreen being applied (3.3±0.2 vs. 1.6±0.2 g, p<0.0001); both men and women applied the recommended amount of sunscreen after in-person counseling (p<0.001, p<0.0001, respectively), however the durability was for only 3 months (applied amount after 3 mo: 2.2±0.5 g, p<0.05). There was no difference in baseline usage, or application after intervention, with or without a history of melanoma; there were increased application amounts in younger age groups; and decreased application amounts of sunscreens with either higher SPF or higher cost. In summary, a hand-out was not effective for sunscreen-use counseling; in-person counseling was very effective in achieving the recommended application amounts, but not durable past 3 mo, indicating the need for improved or reminder counseling after that time period.

Does using a high sun protection factor sunscreen on face, along with physical photoprotection advice, in patients with melasma, change serum vitamin D concentration in Indian conditions? A pragmatic pretest-posttest study.

Use of sunscreens on the face is becoming popular, and patients with melasma are prescribed sunscreen for use on the face. Results of a few Western studies on the effect of sunscreen use on serum vitamin D concentration are not applicable to Indian conditions. To examine the effect of use of a high sun protection factor (SPF 50+, PA++++) sunscreen on face in patients with melasma on serum concentration of 25-hydroxyvitamin D. Forty-five Indian patients (Fitzpatrick skin types III and IV) with melasma were advised to use a sunscreen with SPF 50 + for 3 months, 43 (33 female, 10 male; age 32.9 ± 8 years) completed the study. Patients staying outdoor for <4 hours applied sunscreen once daily after bath. Patients staying outdoors for >4 hours reapplied sunscreen 4 hours after first application. Patients were provided a container to measure the amount of sunscreen for use, which was approximately equal to recommended thickness. Compliance was tested by weighing the used tubes and tubes in use during monthly visits. Serum concentration of 25-hydroxyvitamin D was tested before and after the study period. Amount of sunscreen advised (100.5 ± 29.2 ml) and the actual amount used (96.6 ± 27.9 ml) were similar (P = 0.53, t-test). The difference between serum concentrations of 25-hydroxyvitamin D at the baseline (19.20 ± 9.06 ng/ml) and at 3 months (18.91 ± 8.39 ng/ml) was not significant (P = 0.87, paired t-test, 95% confidence interval of difference -3.33 to 3.92). No correlation was found between the amount of sunscreen used and the percentage change in serum 25-hydroxyvitamin D concentration at 3 months (rho = 0.099, P = 0.528, Spearman's rank correlation). Longer duration of application and a larger sample size may detect minor differences in vitamin D concentration. Using a high SPF sunscreen on the face, along with physical photoprotection advice, in patients with melasma for 3 months does not influence serum 25-hydroxyvitamin D concentration in Indian conditions.

Sunscreen applied at ≥ 2 mg cm-2 during a sunny holiday prevents erythema, a biomarker of ultraviolet radiation-induced DNA damage and suppression of acquired immunity.

Sun protection factor (SPF) is assessed with sunscreen applied at 2 mg cm-2 . People typically apply around 0·8 mg cm-2 and use sunscreen daily for holidays. Such use results in erythema, which is a risk factor for skin cancer. To determine (i) whether typical sunscreen use resulted in erythema, epidermal DNA damage and photoimmunosuppression during a sunny holiday, (ii) whether optimal sunscreen use inhibited erythema and (iii) whether erythema is a biomarker for photoimmunosuppression in a laboratory study. Holidaymakers (n = 22) spent a week in Tenerife (very high ultraviolet index) using their own sunscreens without instruction (typical sunscreen use). Others (n = 40) were given SPF 15 sunscreens with instructions on how to achieve the labelled SPF (sunscreen intervention). Personal ultraviolet radiation (UVR) exposure was monitored electronically as the standard erythemal dose (SED) and erythema was quantified. Epidermal cyclobutane pyrimidine dimers (CPDs) were determined by immunostaining, and immunosuppression was assessed by contact hypersensitivity (CHS) response. There was no difference between personal UVR exposure in the typical sunscreen use and sunscreen intervention groups (P = 0·08). The former had daily erythema on five UVR-exposed body sites, increased CPDs (P < 0·001) and complete CHS suppression (20 of 22). In comparison, erythema was virtually absent (P < 0·001) when sunscreens were used at ≥ 2 mg cm-2 . A laboratory study showed that 3 SED from three very different spectra suppressed CHS by around ~50%. Optimal sunscreen use prevents erythema during a sunny holiday. Erythema predicts suppression of CHS (implying a shared action spectrum). Given that erythema and CPDs share action spectra, the data strongly suggest that optimal sunscreen use will also reduce CPD formation and UVR-induced immunosuppression.

Sun behaviour and physical activity associated with autumn vitamin D status in 4-8-year-old Danish children.

To explore determinants of serum 25-hydroxyvitamin D (s-25(OH)D) during autumn in young, Caucasian children not consuming vitamin D-fortified foods or supplements, and explore differences in sun behaviours between pre-school and school children. In September-October, s-25(OH)D was measured by LC-MS/MS; physical activity, sun behaviours and vitamin D intake were assessed with questionnaires. Baseline data from the ODIN Junior trial at 55°N. Children aged 4-8 years (n 130), of whom 96% gave blood samples. Mean s-25(OH)D was 56·8 (sd 12·5) nmol/l and positively associated with fat-free mass index (P=0·014). Children being active 6-7 h/week had 5·6 (95% CI 1·1, 10·0) nmol/l higher s-25(OH)D than less active children (P=0·014). Children seeking shade sometimes or rarely/never had 7·0 (95% CI 1·2, 12·9; P=0·018) and 7·2 (95% CI 0·8, 13·6; P=0·028) nmol/l higher s-25(OH)D, respectively, than children always/often seeking shade. Pre-school children had more sun-safe behaviour than school children in terms of use of a hat, sunscreen and sunscreen sun protection factor (P<0·05). In school but not pre-school children, using a hat rarely/never was associated with 12·1 (95% CI 2·5, 21·7; P=0·014) nmol/l higher s-25(OH)D v. always/often (P interaction=0·019). Vitamin D intake was not associated with s-25(OH)D (P=0·241). Physical activity and sun behaviours are associated with s-25(OH)D in young children. Identifying factors influencing autumn s-25(OH)D is relevant to optimize levels before sun exposure diminishes. Strategies to reduce risk of inadequacy should consider risk of skin cancer and sunburn, and could include fortification and/or vitamin D supplementation.