A sun holiday is a sunburn holiday

Is sunscreen alone effective at preventing sunburn on a high-solar beach vacation: A modeling study?

Beach holidays in areas of strong sunlight are popular and sunscreen is often the primary means of photoprotection favored by many people. The object of this study was to estimate how effective sunscreen is in preventing sunburn under high ultraviolet (UV) levels. We used a computational model to determine how the quantity, frequency, substantivity, and labeled SPF of applied sunscreens impact on the predicted erythemal response in unacclimatized skin over the course of a 7-day holiday in a high-solar environment. Our results indicated that sunscreen on its own may be insufficient to prevent sunburn in white skin on a sun-seeking holiday that combines prolonged exposure with high UV levels. Nevertheless, sunscreens have a valuable role to play on a beach holiday especially if an SPF30 or higher is chosen, the product is applied liberally and uniformly, application is started early into the sun exposure period and repeated at 2-hourly intervals throughout the day, and the product binds well to the skin. The main limitation of our investigation is that it is not an observational study but rather a computational model and while all models are wrong, some, including this one, are useful.

The adverse consequences of not using sunscreens

The adverse effects of solar ultraviolet radiation (UVR) on normal skin are well established, especially in those with poorly melanized skin. Clinically, these effects may be classified as acute, such as erythema or chronic such as keratinocyte and melanocyte skin cancers. Apart from skin type genetics, clinical responses to solar UVR are dependent on geophysical (e.g., solar intensity) and behavioural factors. The latter are especially important because they may result in 'solar overload' with unwanted clinical consequences and ever greater burdens to healthcare systems. Correctly used, sunscreens can mitigate the acute and chronic effects of solar UVR exposure. Laboratory studies also show that sunscreens can inhibit the initial molecular and cellular events that are responsible for clinical outcomes. Despite public health campaigns, global trends continue to show increasing incidence of all types of skin cancer. Large-scale epidemiological studies have shown the benefits of sunscreen use in preventing skin cancer, though it is likely that sunscreen use has not been optimal in such studies. It is evident that without substantial changes in sun-seeking behaviour, sunscreen use is a very important part of the defence against the acute and chronic effects of solar exposure. Ideally, sunscreens should be able to provide the level of protection that reduces the risk of skin cancer in susceptible skin types to that observed in heavily melanized skin.

Behaviour and sun exposure in holidaymakers alters skin microbiota composition and diversity

Introduction: The skin microbiota plays a crucial role in maintaining epidermal homeostasis. Ultraviolet radiation (UVR) and other environmental challenges can impact the skin microbiota through direct and indirect mechanisms. This study aimed to investigate the effects of sun exposure on the skin microbiota and its relationship with individual skin phototypes. Methods: Healthy volunteers (n = 21 [4M, 17 F], mean age 33.2 years) holidayed in a sunny destination for a minimum of 7 days with swabs taken pre-holiday and up to 84 days post-holiday. Participant group was categorised by individual typology angle (ITA) classification and the composition of the skin microbiota was examined using 16S rRNA gene sequencing. Results: In the entire cohort and at all time points, the major bacterial phyla were Actinobacteria, Proteobacteria and Firmicutes. There was a significant change in microbial beta diversity at day 28 post-holiday, compared to baseline, for all participants. However, when participants were segregated into three cohorts dependent on the degree of skin tanning response between baseline (pre-holiday) and immediately one-day post-holiday, there was a reduction in Proteobacteria in the sun-seeking participants 1 day after the holiday, which recovered over time. Discussion: These findings suggest that sun exposure can affect the diversity and composition of the skin microbiota, which may have downstream effects on skin health.

Ultraviolet exposure to the face in patients with xeroderma pigmentosum and healthy controls: applying a novel methodology to define photoprotection behaviour

BACKGROUND

In Xeroderma Pigmentosum (XP), the main means of preventing skin and eye cancers is extreme protection against ultraviolet radiation (UVR). Protection is most important for the face.

OBJECTIVES

We aimed to assess how well patients with XP adhere to medical advice to protect against UVR by objectively estimating the mean daily dose of UVR to the face.

METHODS

We objectively estimated the UVR dose to the face in 36 XP patients and 25 healthy individuals over 3 weeks in the summer. We used a new methodology which combined UVR dose measurements from a wrist-worn dosimeter with an activity diary record of face photoprotection behaviour for each 15 minute period spent outside. A protection factor was associated with each behaviour, and the data analysed using a negative binomial mixed-effects model.

RESULTS

The mean daily UVR dose (weighted for DNA damage capacity) to the face in the XP patients was 0.13 Standard Erythemal Doses (SED) (mean in healthy individuals = 0.51 SED). There was wide variation between patients (range <0.01 - 0.48 SED/day). Self-caring adult patients had a very similar UV dose to the face to cared-for patients (0.13 vs 0.12 SED/day) despite photoprotecting much more poorly when outside, because the self-caring adults were outside in daylight much less.

CONCLUSIONS

Photoprotection behaviour varies widely within the XP group indicating that non-adherence to photoprotection advice is a significant issue. Timing and duration of going outside are as important as photoprotective measures taken when outside, to determine the UVR exposure to the face. This new methodology will be of value in identifying the sources of UVR exposure in other conditions where facial UV exposure is a key outcome, particularly in patients with multiple non-melanoma skin cancers.

Difference in Sun Exposure Habits Between Individuals with High and Low Risk of Skin Cancer

Background

Skin cancer incidence is rapidly increasing. The main risk factor, sun exposure, can be modified. Informational campaigns can be effective in raising skin cancer awareness and target the high-risk population. Still, sun exposure habits in people at high risk of skin cancer are not well-known.

Objective

To investigate if and how sun exposure habits differ between low-risk and high-risk individuals.

Methods

During the Swedish Euromelanoma campaign of 2018, questionnaires were collected containing information regarding sun exposure habits and risk factors for skin cancer. Data on 4,141 participants was used to investigate the association between risk factors and sun exposure habits.

Results

A fair skin type and a previous history of skin cancer were significantly associated with enhanced sun protective behavior. Family history of skin cancer, childhood sunburns and the presence of large/atypical nevi had no effect on sun exposure habits. Going on sunny holidays were particularly unaffected by being at high risk of skin cancer.

Conclusion

Individuals at high risk of developing skin cancer showed suboptimal sun exposure habits and harmful traveling behaviors. We suggest that future skin cancer campaigns inform on accurate sun protection behavior during sunny holidays and associated risk factors. Risk factors such as childhood sunburns, numerous common and large/atypical nevi, as well as family history of skin cancer seem to be less recognized by the population.

"Beach Lifeguards' Sun Exposure and Sun Protection in Spain"

BACKGROUND

Sunburn is the main avoidable cause of skin cancer. Beach lifeguards spend many hours exposed to the effects of solar radiation during their work day, precisely at times of the year when levels of solar irradiation are highest. The aim of this study is to quantify the risk to beach lifeguards of sun exposure.

METHODS

A descriptive cross-sectional study was carried out in the Western Costa del Sol, southern Spain, during the summer of 2018. The research subjects were recruited during a skin cancer prevention course for beach lifeguards. All participants were invited to complete a questionnaire on their habits, attitudes, and knowledge related to sun exposure. In addition, ten were specially monitored using personal dosimeters for three consecutive days, and the results were recorded in a photoprotection diary. A descriptive analysis (mean and standard deviation for the quantitative variables) was performed, and inter-group differences were evaluated using the Mann-Whitney U test.

RESULTS

Two hundred fifteen lifeguards completed the questionnaire, and 109 met the criteria for inclusion in this analysis. The mean age was 23.8 years (SD: 5.1), 78.0% were male, 71.5% were phototype III or IV (Fitzpatrick's phototype), and 77.1% had experienced at least one painful sunburn during the previous summer. The mean daily personal ultraviolet exposure per day, the minimal erythema dose, and the standard erythema dose, in J/m2, were 634.7 [standard deviation (SD): 356.2], 2.5 (SD: 1.4) and 6.35 (SD: 3.6), respectively.

CONCLUSION

Beach lifeguards receive very high doses of solar radiation during the work day and experience correspondingly high rates of sunburn. Intervention strategies to modify their sun exposure behavior and working environment are necessary to reduce the risk of skin cancer for these workers and to promote early diagnosis of the disease.

Novel sunprotection interventions to prevent skin cancer: A randomized study targeting Danes going on vacation to destinations with high UV index

Background

In Denmark, 16,500 cases of melanoma and keratinocyte cancers were registered in 2015, of which 90% could have been avoided by behavioral changes. We aimed to test novel interventions in a randomized design. The interventions targeted Danes going on vacation to high UVI destinations aiming to decrease sunburn by increasing use of sun protection to prevent skin cancer in the Danish population.

Methods

We report a randomized behavioral intervention during May-Dec 2018 with 1548 Danish adults on vacation in 2018 for a period of 1–3 weeks. The study population was population-based and aged 18–65 years. We tested two protection routines against minimal intervention control group (2-by2-factorial design): 1) Avoidance of the sun during peak hours and shade, use of the UV-index and planning of indoor/outdoor activity respectively and, 2) Coverage by increasing use of the hat advice and increasing sunscreen amount by application routine. Outcome was use of protection and sunburn.

Results

There were no differences in sunburn prevalence between intervention and control groups. Protection routine 1 and 2 both increased the overall protection score compared to non-users. Protection routine 1 increased the reported use of shade and decreased time exposed in the sun. Protection routine 2 increased the use of hat and sunscreen amount.

Conclusion

Simple measures can help avoid the majority of one of the most widespread cancers worldwide. Vacations to high UVI destinations is a major influence on the annual Danish UV-exposure. We influenced travelers to protect themselves better and to increase sun protection behavior.

A Handful of Sunscreen for Whole-Body Application

BACKGROUND

The rule of thumb "Fill up a handful of sunscreen and spread it all over your body" has been used in several sun safety campaigns. The intention was to increase the applied sunscreen to obtain a quantity of 2 mg/cm² to all accessible skin. The present study is the first to investigate how this advice works in practice, evaluated by quantity of sunscreen applied and amount of covered skin.

METHODS

Seventeen volunteers wearing swimwear were asked to "Fill up a handful and spread it all over your body." Before and after sunscreen application, the volunteers were photographed in black light. As sunscreen absorbs black light, the darkness of the skin increases with increasing amounts of applied sunscreen, making it possible to identify skin left without coverage. The sunscreen container was weighed before and after to quantify the amount of sunscreen applied.

RESULTS

A median of 21% of the accessible skin was left completely without coverage. The 79% covered area was covered with a median of 1.12 mg/cm², not the expected 2 mg/cm².

CONCLUSION

In practice, the advice "Fill up a handful of sunscreen and spread it all over your body" led to a better but still modest protection, compared to the intended effect.

Insufficient Sun Exposure Has Become a Real Public Health Problem

This article aims to alert the medical community and public health authorities to accumulating evidence on health benefits from sun exposure, which suggests that insufficient sun exposure is a significant public health problem. Studies in the past decade indicate that insufficient sun exposure may be responsible for 340,000 deaths in the United States and 480,000 deaths in Europe per year, and an increased incidence of breast cancer, colorectal cancer, hypertension, cardiovascular disease, metabolic syndrome, multiple sclerosis, Alzheimer's disease, autism, asthma, type 1 diabetes and myopia. Vitamin D has long been considered the principal mediator of beneficial effects of sun exposure. However, oral vitamin D supplementation has not been convincingly shown to prevent the above conditions; thus, serum 25(OH)D as an indicator of vitamin D status may be a proxy for and not a mediator of beneficial effects of sun exposure. New candidate mechanisms include the release of nitric oxide from the skin and direct effects of ultraviolet radiation (UVR) on peripheral blood cells. Collectively, this evidence indicates it would be wise for people living outside the tropics to ensure they expose their skin sufficiently to the sun. To minimize the harms of excessive sun exposure, great care must be taken to avoid sunburn, and sun exposure during high ambient UVR seasons should be obtained incrementally at not more than 5-30 min a day (depending on skin type and UV index), in season-appropriate clothing and with eyes closed or protected by sunglasses that filter UVR.

Preventing Skin Cancer Among Staff and Guests at Seaside Hotels

Beach users and outdoor workers in resort areas are major risk groups for skin cancer, and therefore seaside hotels constitute a strategic area in which to conduct awareness-raising campaigns and interventions. The main aim of the present study is to describe habits, attitudes and knowledge related to sun exposure, the sunburn events experienced and potentially malignant skin lesions observed among hotel staff and guests recruited during a skin cancer prevention campaign at seaside hotels in the western Costa del Sol (southern Spain). This descriptive cross-sectional study was conducted at four seaside hotels in the western Costa del Sol. An 8-day awareness-raising campaign on skin cancer was conducted for hotel guests and staff, who were invited to complete a questionnaire about their habits, attitudes and knowledge regarding photoprotection, and to receive a comprehensive skin examination. The questionnaire on habits, attitudes and knowledge related to sun exposure was completed by 542 participants. The most common photoprotection practice was the use of sunglasses (79.3%). Potentially dangerous lesions were identified in 39 persons (14%). In addition, 94.0% reported having gained new knowledge, 89.6% had changed their attitudes towards sun tanning and 94.7% intended to improve their photoprotection practices in the future. Seaside hotels are an optimal scenario for conducting studies aimed at skin cancer prevention and reduction. Further studies should be carried out in other geographical areas to confirm our results, to evaluate the costs and benefits of such interventions and determine their long-term impact on health.

Sunscreen photoprotection and vitamin D status

Background

Global concern about vitamin D deficiency has fuelled debates on photoprotection and the importance of solar exposure to meet vitamin D requirements.

Objectives

To review the published evidence to reach a consensus on the influence of photoprotection by sunscreens on vitamin D status, considering other relevant factors.

Methods

An international panel of 13 experts in endocrinology, dermatology, photobiology, epidemiology and biological anthropology reviewed the literature prior to a 1‐day meeting in June 2017, during which the evidence was discussed. Methods of assessment and determining factors of vitamin D status, and public health perspectives were examined and consequences of sun exposure and the effects of photoprotection were assessed.

Results

A serum level of ≥ 50 nmol L⁻¹ 25(OH)D is a target for all individuals. Broad‐spectrum sunscreens that prevent erythema are unlikely to compromise vitamin D status in healthy populations. Vitamin D screening should be restricted to those at risk of hypovitaminosis, such as patients with photosensitivity disorders, who require rigorous photoprotection. Screening and supplementation are advised for this group.

Conclusions

Sunscreen use for daily and recreational photoprotection does not compromise vitamin D synthesis, even when applied under optimal conditions.

What's already known about this topic?

Knowledge of the relationship between solar exposure behaviour, sunscreen use and vitamin D is important for public health but there is confusion about optimal vitamin D status and the safest way to achieve this.

Practical recommendations on the potential impact of daily and/or recreational sunscreens on vitamin D status are lacking for healthy people.

What does this study add?

Judicious use of daily broad‐spectrum sunscreens with high ultraviolet (UV) A protection will not compromise vitamin D status in healthy people.

However, photoprotection strategies for patients with photosensitivity disorders that include high sun‐protection factor sunscreens with high UVA protection, along with protective clothing and shade‐seeking behaviour are likely to compromise vitamin D status.

Screening for vitamin D status and supplementation are recommended in patients with photosensitivity disorders.

Linked Comment: https://doi.org/10.1111/bjd.18126.

https://doi.org/10.1111/bjd.18494 available online

Ultraviolet radiation sensors: a review

Knowledge of when to actively modify outdoor sun protective behaviour is crucial for sun safety and should be based upon personal susceptibility to sunburn and the intensity of the ultraviolet radiation dose during outdoor exposure. To facilitate measurements of dose and exposure, non-scientific and research-grade instruments measuring different exposure parameters of solar radiation are commercially available. These devices have been marketed as weather stations, purpose-built UVI display stations, portable dosimeters, handheld solarmeters, watches, and even stickers that can be worn. According to their measurements, the public can be educated and reminded to adopt appropriate sun safety practices such as limiting midday sun exposure, seeking shade, wearing protective clothing such as a broad-brimmed hat, and regularly applying and reapplying broad-spectrum sunscreen. There are many different commercial devices and smart phone applications (apps) that allow the public to be informed about current ultraviolet radiation levels in their immediate area, but each aims to enable the public to practise good sun safety behaviour. Naturally, each device is not without its various limitations and unique advantages. This study explores the ways in which ultraviolet radiation sensors can provide an accurate and highly convenient way of practising good sun safety behaviour in various contexts of high sun exposure such as playgrounds, tourist attractions, workplaces, and swimming pools. However, the author advises caution on the use of personal meters that have not been validated for their reliability and accuracy as public health tools.

Optimal sunscreen use, during a sun holiday with a very high ultraviolet index, allows vitamin D synthesis without sunburn

Background

Sunlight contains ultraviolet (UV)A and UVB radiation. UVB is essential for vitamin D synthesis but is the main cause of sunburn and skin cancer. Sunscreen use is advocated to reduce the sun's adverse effects but may compromise vitamin D status.

Objectives

To assess the ability of two intervention sunscreens to inhibit vitamin D synthesis during a week‐long sun holiday.

Methods

The impact of sunscreens on vitamin D status was studied during a 1‐week sun holiday in Tenerife (28° N). Comparisons were made between two formulations, each with a sun protection factor (SPF) of 15. The UVA‐protection factor (PF) was low in one case and high in the other. Healthy Polish volunteers (n = 20 per group) were given the sunscreens and advised on the correct application. Comparisons were also made with discretionary sunscreen use (n = 22) and nonholiday groups (51·8° N, n = 17). Sunscreen use in the intervention groups was measured. Behaviour, UV radiation exposure, clothing cover and sunburn were monitored. Serum 25‐hydroxyvitamin D₃ [25(OH)D₃] was assessed by high‐performance liquid chromatography–tandem mass spectrometry.

Results

Use of intervention sunscreens was the same (P = 0·60), and both equally inhibited sunburn, which was present in the discretionary use group. There was an increase (P < 0·001) in mean ± SD 25(OH)D₃ (28·0 ± 16·5 nmol L⁻¹) in the discretionary use group. The high and low UVA‐PF sunscreen groups showed statistically significant increases (P < 0·001) of 19·0 ± 14·2 and 13·0 ± 11·4 nmol L⁻¹ 25(OH)D₃, respectively with P = 0·022 for difference between the intervention sunscreens. The nonholiday group showed a fall (P = 0·08) of 2·5 ± 5·6 nmol L⁻¹ 25(OH)D₃.

Conclusions

Sunscreens may be used to prevent sunburn yet allow vitamin D synthesis. A high UVA‐PF sunscreen enables significantly higher vitamin D synthesis than a low UVA‐PF sunscreen because the former, by default, transmits more UVB than the latter.

What's already known about this topic?

Action spectra (wavelength dependence) for erythema and the cutaneous formation of vitamin D overlap considerably in the ultraviolet (UV)B region.

Theoretically, sunscreens that inhibit erythema should also inhibit vitamin D synthesis.

To date, studies on the inhibitory effects of sunscreens on vitamin D synthesis have given conflicting results, possibly, in part, because people typically apply sunscreen suboptimally.

Many studies have design flaws.

What does this study add?

Sunscreens (sun protection factor, SPF 15) applied at sufficient thickness to inhibit sunburn during a week‐long holiday with a very high UV index still allow a highly significant improvement of serum 25‐hydroxyvitamin D₃ concentration.

An SPF 15 formulation with high UVA protection enables better vitamin D synthesis than a low UVA protection product. The former allows more UVB transmission.

Linked Editorial: https://doi.org/10.1111/bjd.18273.

https://doi.org/10.1111/bjd.18492 available online

https://www.bjdonline.com/article/optimal-sunscreen-use-during-a-sun-holiday-with-a-very-high-ultraviolet-index-allows-vitamin-d-synthesis-without-sunburn/

Personal electronic UVR dosimeter measurements: specific and general uncertainties

Personal ultraviolet radiation (UVR) dosimetry has been performed for decades to objectively measure human exposure to UVR. These measurements have been used to investigate solar behaviour and its negative effects on human health such as skin cancer and positive effects such as vitamin D formation. A specific electronic dosimeter is described with a spectral sensitivity as the erythema response for human skin and temperature measurements for compliance control. Technical, methodological and environmental causes of uncertainties regarding personal UV dosimetry are investigated using this dosimeter as an example, which enables us to show the dosimeter's limitations and enables readers to compare their dosimeters with that described and to increase awareness of imperfections of dosimeters. The dosimeter's spectral response, cosine response, linearity, temperature dependency and sensitivity are investigated. As opposed to biological and chemical dosimeters, electronic dosimeters do not measure UV radiation continuously but at time-intervals (sampling). The error introduced by sampling is investigated for sampling intervals from 1 second up to 60 seconds for 3 groups of people (n = 18, 1.1-4.6 hours of positive UV measurements) on sunny (n = 12) and cloudy (n = 6) days. Increasing the sample time by 1 second added on average an uncertainty of maximum +0.29% to -0.27% per added second compared to the 1-second sample time. The importance of dirt on the sensor was investigated in 24 dosimeters after 6 months use by farmers. The reduction in the registered dose due to the dirty sensor was 2.3% (median = 2.0%, inter-quartile range = 2.0%, max = 5%) suggesting that dirt on the sensor generally does not play a significant role.

Children sustain high levels of skin DNA photodamage, with a modest increase of serum 25-hydroxyvitamin D3 , after a summer holiday in Northern Europe

BACKGROUND

Childhood solar ultraviolet radiation (UVR) exposure increases the risk of skin cancer in adulthood, which is associated with mutations caused by UVR-induced cyclobutane pyrimidine dimers (CPD). Solar UVR is also the main source of vitamin D, essential for healthy bone development in children.

OBJECTIVES

To assess the impact of a 12-day Baltic Sea (54° N) beach holiday on serum 25-hydroxyvitamin D₃ [25(OH)D₃ ] and CPD in 32 healthy Polish children (skin types I-IV).

METHODS

Blood and urine were collected before and after the holiday and assessed for 25(OH)D₃ and excreted CPD, respectively, and personal UVR exposure was measured. Diaries were used to record sunbathing, sunburn and sunscreen use. Before- and after-holiday skin redness and pigmentation were measured by reflectance spectroscopy.

RESULTS

The average ± SD daily exposure UVR dose was 2·4 ± 1·5 standard erythema doses (SEDs), which is borderline erythemal. The mean concentration of 25(OH)D₃ increased (× 1·24 ± 0·19) from 64·7 ± 13·3 to 79·3 ± 18·7 nmol L^-1 (P < 0·001). Mean CPD increased 12·6 ± 10·0-fold from 26·9 ± 17·9 to 248·9 ± 113·4 fmol μmol^-1 creatinine (P < 0·001). Increased 25(OH)D₃ was accompanied by a very much greater increase in DNA damage associated with carcinogenic potential. Overall, skin type had no significant effects on behavioural, clinical or analytical outcomes, but skin types I/II had more CPD (unadjusted P = 0·0496) than skin types III/IV at the end of the holiday.

CONCLUSIONS

Careful consideration must be given to the health outcomes of childhood solar exposure, and a much better understanding of the risk-benefit relationships of such exposure is required. Rigorous photoprotection is necessary for children, even in Northern Europe.

Sunscreen use optimized by two consecutive applications

Sunscreen users are often inadequately protected and become sunburned. This study aimed to investigate how much two consecutive sunscreen applications increased the quantity of sunscreen applied and decreased the skin area left without sunscreen (missed area) compared to a single application. Thirty-one healthy volunteers wearing swimwear were included and applied sunscreen two consecutive times in a laboratory environment. Participants had pictures taken in black light before and after each application. As sunscreens absorb black light, the darkness of the skin increased with increasing amounts of sunscreen applied. We conducted a standard curve establishing a link between change in picture darkness and quantity of sunscreen. The quantity of sunscreen at selected skin sites as well as the percentage of missed area was determined after each application. Participants had missed a median of 20% of their available body surface after a single application. After double application they had missed 9%. The decrease in missed areas was significant for the whole body surface and for each of the body regions separately. The median participant had applied between 13% and 100% more sunscreen at the selected skin sites after double application than after single application. We recommend double application, especially before intense sun exposure.

Reliability and consistency of a validated sun exposure questionnaire in a population-based Danish sample

An important feature of questionnaire validation is reliability. To be able to measure a given concept by questionnaire validly, the reliability needs to be high.

The objectives of this study were to examine reliability of attitude and knowledge and behavioral consistency of sunburn in a developed questionnaire for monitoring and evaluating population sun-related behavior.

Sun related behavior, attitude and knowledge was measured weekly by a questionnaire in the summer of 2013 among 664 Danes. Reliability was tested in a test-retest design. Consistency of behavioral information was tested similarly in a questionnaire adapted to measure behavior throughout the summer.

The response rates for questionnaire 1, 2 and 3 were high and the drop out was not dependent on demographic characteristic. There was at least 73% agreement between sunburns in the measurement week and the entire summer, and a possible sunburn underestimation in questionnaires summarizing the entire summer. The participants underestimated their outdoor exposure in the evaluation covering the entire summer as compared to the measurement week. The reliability of scales measuring attitude and knowledge was high for majority of scales, while consistency in protection behavior was low.

To our knowledge, this is the first study to report reliability for a completely validated questionnaire on sun-related behavior in a national random population based sample. Further, we show that attitude and knowledge questions confirmed their validity with good reliability, while consistency of protection behavior in general and in a week's measurement was low.

•

Objectively validated questionnaires tested for reliability/behavioral consistency.

•

Strong reliability of the knowledge and attitude items was shown.

•

Knowledge about behavioral consistency between questionnaire measurement periods

•

A recommendable design for short term evaluation of skin cancer prevention campaigns

An investigation of the predictors of photoprotection and UVR dose to the face in patients with XP: a protocol using observational mixed methods

INTRODUCTION

Xeroderma pigmentosum (XP) is a rare genetic condition caused by defective nucleotide excision repair and characterised by skin cancer, ocular and neurological involvement. Stringent ultraviolet protection is the only way to prevent skin cancer. Despite the risks, some patients' photoprotection is poor, with a potentially devastating impact on their prognosis. The aim of this research is to identify disease-specific and psychosocial predictors of photoprotection behaviour and ultraviolet radiation (UVR) dose to the face.

METHODS AND ANALYSIS

Mixed methods research based on 45 UK patients will involve qualitative interviews to identify individuals' experience of XP and the influences on their photoprotection behaviours and a cross-sectional quantitative survey to assess biopsychosocial correlates of these behaviours at baseline. This will be followed by objective measurement of UVR exposure for 21 days by wrist-worn dosimeter and daily recording of photoprotection behaviours and psychological variables for up to 50 days in the summer months. This novel methodology will enable UVR dose reaching the face to be calculated and analysed as a clinically relevant endpoint. A range of qualitative and quantitative analytical approaches will be used, reflecting the mixed methods (eg, cross-sectional qualitative interviews, n-of-1 studies). Framework analysis will be used to analyse the qualitative interviews; mixed-effects longitudinal models will be used to examine the association of clinical and psychosocial factors with the average daily UVR dose; dynamic logistic regression models will be used to investigate participant-specific psychosocial factors associated with photoprotection behaviours.

ETHICS AND DISSEMINATION

This research has been approved by Camden and King's Cross Research Ethics Committee 15/LO/1395. The findings will be published in peer-reviewed journals and presented at national and international scientific conferences.

Comparing Handheld Meters and Electronic Dosimeters for Measuring Ultraviolet Levels under Shade and in the Sun

This study aimed to compare the validity, reliability and practicality of alternative portable methods for measuring erythemal UVR levels in passive recreation areas in public parks. UVR levels were measured for point in time comparisons between Solarmeter 6.5 handheld meters and time-stamped electronic dosimeters in a large central park in Melbourne, Australia. Observations were made at 20 locations in the park by two research assistants under two conditions: (1) matched shade (2) contrasting shade-no shade. Comparisons were also made with scientific instruments on the UVR monitoring station rooftop and by remotely selecting UV records and forecasts on cloud-free dates of park observations. There was good agreement between the portable UVR instruments in the park setting as confirmed via Bland Altman plots, while the dosimeter appeared less sensitive to change in shade conditions. The rooftop measurements showed that the Solarmeter 6.5 UVR readings were comparable to those of the adjacent rooftop instruments. The practicalities of using the dosimeters and Solarmeters for behavioral studies are discussed. These findings provide a basis for use of the Solarmeter 6.5 to measure changes in UVR levels due to different environmental conditions with relative accuracy for intervention studies in outdoor settings.

Incidence and survival in patients with cutaneous melanoma by morphology, anatomical site and TNM stage: a Danish Population-based Register Study 1989-2011

INTRODUCTION

The incidence of melanoma of the skin has risen in Denmark in recent decades, the increase being steeper from 2004. It is unclear whether this represents a true rise in incidence or whether it is caused by an increased awareness of the condition.

METHODS

To assess whether the increase was characterised by early-stage melanomas and a higher proportion of melanomas with superficial spreading morphology, we studied all skin melanoma patients registered in the Danish Cancer Register 1989-2011 (n=27,010) and followed up for death through 2013. Trends in age-standardised incidence by sex, subsite and morphology, relative survival, TNM stage distribution and stage-specific relative survival from 2004 were analysed.

RESULTS

The incidence of melanoma more than doubled over 23 years. A steeper increase from 2004 was driven mainly by superficial spreading tumours, but the proportion of nodular melanomas in patients 50 years of age and over also increased significantly. The largest increase occurred for stage I tumours and for tumours on the trunk. From 1989-1993 to 2009-2011 the 5-year relative survival increased at 12% and 6% points for male and female patients, respectively.

INTERPRETATION

Greater awareness, and thus lower stage at diagnosis (mediated by a large skin cancer prevention campaign from 2007), might explain part of the increase, but the increase in nodular melanoma also points to a genuine increase in the risk of melanoma.

Socioeconomic status and cutaneous malignant melanoma in Northern Europe

Socioeconomic status (SES) is associated with cutaneous malignant melanoma (CMM) in Northern Europe, despite equal access to health care. SES per se is not responsible for this association, which must be ascribed to important risk factors for CMM such as intermittent ultraviolet radiation (UVR) exposure, and screening for CMM possibly owing to a greater knowledge and understanding of CMM. Our review of the literature showed that high SES is associated with increased risk of CMM, thinner tumours, increased survival and decreased mortality from CMM - the latter shown among women, and in recent studies also among men. There is evidence that high SES is associated with sun holidays, whereas low SES is associated with the use of sunbeds. Findings suggest that high SES is associated with the use of physicians and dermatologists for marks and moles, possibly owing to more knowledge and better understanding of CMM. We conclude that there has been a true increase in CMM incidence among high SES individuals in Northern Europe probably due to past intense intermittent UVR exposure, especially in connection with sun holidays. However, the increased risk of CMM and a better outcome of CMM in high SES individuals may also be conditioned by frequent recourse to physicians, which may be ascribed to more knowledge and better understanding of CMM, although more studies on this subject are warranted. Thicker CMM tumours and increased CMM mortality among low SES individuals in recent decades may reflect exposure to intermittent UVR, such as the use of sunbeds, as well as delayed diagnosis.