Sunburn Protection Research Articles

Sunburn protection by sun protection factor (SPF) 85 and SPF 50 sunscreens at high altitudes

Sunburn protection by sun protection factor (SPF) 85 and SPF 50 sunscreens at high altitudes

Evaluation of sunburn protection by a single application of an SPF 70 formulation at high altitudes under extreme sun conditions

Evaluation of sunburn protection by a single application of an SPF 70 formulation at high altitudes under extreme sun conditions

Skin Protection by Sunscreens Is Improved by Explicit Labeling and Providing Free Sunscreen

Whatever the improvement in the protection spectrum of sunscreens (SCs), actual skin protection mainly depends on the way they are used, especially on the quantity applied. This prospective randomized study assessed how much sun protection factor (SPF) labeling, which is hardly understandable by a layman, and high cost account for misuse of SCs. In three beach resorts in France, 364 individuals were blindly randomized during their holidays to three arms (1) free SCs intervention (FS) = four types of SCs with their usual SPF label (60B-A, 20B-A, 12B-A, 6B-3A) at free disposal; (2) same free SCs with an explicit labeling (FNL), including sunburn protection, likely protection against long-term effects of UV, and possibility to get a tan; and (3) no intervention (NI). As compared to FS, FNL increased the quantity of SCs applied, mainly in the minority of people who were not "tan-seekers", reduced sunburns particularly in sun-sensitive individuals (25.6 vs 58.3%, P=0.005), and induced a shift in the level of SCs chosen. Free delivery SCs were associated with a more systematic application of SCs in case of exposure, and a decreased sunburn occurrence, without increase of exposure. These results suggest that a labeling more explicit for the public would result in a better protection in SC users and that cost could be a limiting factor to use SC as often as necessary.

Pretravel Health Advice among International Travelers Visiting Cuzco, Peru

Cuzco, a Peruvian city of historical interest located 3,326 m above sea level, is a frequent destination for tourists. We conducted a descriptive study to assess the extent and sources of pretravel health advice received by international travelers before their arrival to Cuzco. Data were collected as part of a health survey among travelers. Between August and November 2002, travelers between 15 and 65 years old were invited to fill out a questionnaire in the departing area of Cuzco's international airport. A total of 5,988 travelers participated. The mean age was 35.4 years (SD 11.4 yr); 50.6% were female and 50.8% were single. Tourism was the reason for traveling in 90.2% of the participants, and 89.3% of them were traveling with companions. Pretravel health information was received by 93.6%. The median number of information sources was two, with books (41.5%), travel medicine clinics (38.8%), the Internet (23.3%), and general practitioners (22.7%) as the main sources. Most frequently received recommendations were about safe food and water consumption (85%), use of insect repellents (66.0%), sunburn protection (64.4%), and condom use (22%). Only 16.5% took medication to prevent altitude sickness, and 14.2% took medication to prevent traveler's diarrhea. Variables independently associated with receiving pretravel health information from a health care professional were female gender, country of residence other than the United States, length of stay in Cuzco > 7 days, length of stay in other Peruvian cities > 7 days, tourism as the main reason for visiting Cuzco, traveling with companions, and consulting of more than one source of information. Most travelers arriving to Cuzco had received pretravel health information, and the majority obtained it from more than one source. Recommendations addressed for specific health risks, such as altitude sickness prophylaxis, were received by few travelers.

Clinical potential of Melanotan® (NDP‐α‐MSH) in skin protection – current status and future perspective

There is good epidemiological evidence that melanin in the skin protects against sunburn and skin cancer resulting from excessive ultraviolet radiation (UVR) exposure. Melanin is synthesized in a multistep biochemical pathway within specialized cell types in human skin called melanocytes situated in the epidermis. UV light causes an increase in melanocyte‐stimulating hormone (α‐MSH) receptor activity on cutaneous melanocytes (MC1‐R) that results in an increase of eumelanin within the epidermal melanocytes. Melanotan is a synthetic analogue of α‐MSH with potent melanogenic activity in animals and humans. We have recently completed a double‐blind, randomized controlled study in 80 healthy Caucasian adult subjects. A fixed dose of Melanotan (0.16 mg/kg/day) or placebo in a 3 : 1 ratio was given as three cycles of daily subcutaneous injections over 10 days each month for three consecutive months. Changes in skin pigmentation were quantified by serial skin reflectance measurements and UVR injury, as determined by ×3 MED exposure to broadband UVR, was assessed by measurement of apoptosis (sunburn cells). Results demonstrated that a highly significant increase in skin melanin was attained in all subjects on active treatment compared with placebo, and this was especially pronounced in subjects with lighter skin types (Fitzpatrick I and II; P < 0.0001). In these latter subjects, significant sunburn protection was also determined. The ability of Melanotan to stimulate melanin production without the associated UV‐induced skin damage may prove a useful adjunct to current photoprotective strategies to stem the marked rise in skin cancer incidence. Currently, we are studying the therapeutic efficacy of a slow‐release implant of Melanotan in skin disorders such as polymorphic light eruption and psoriasis.

Relationship between UVA protection and skin response to UV light: proposal for labelling UVA protection

Definition and validation of a most relevant method to assess ultravoilet A (UVA) protection is a major concern for industry, authorities and consumers. However, due to the lack of knowledge about all the biological phenomena involved, the level of UVA protection needed, the ways to assess and label it, remain controversial. In order to overcome this situation, the paper deals with the outcomes of a mathematical model to calculate the distribution between ultravoilet B (UVB) and UVA components of skin responses to UV light. Mathematical calculations of UVB and UVA erythemal components of skin response to sunlight are developed from the well-known determination procedure to calculate the sunburn protection factor (SPF) of sunscreens. The model establishes the relationship between the UVA component of skin erythemal response to overall UV radiation received from sunlight and the ratio SPF/PFAe (erythemal protection factor) where SPF is the product and PFAe is related to the UVA part of the sunlight. Depending on the efficacy profile of sunscreens, the skin erythemal response may be mainly promoted by UVB rays as it normally occurs in unprotected skin or on contrary by UVA rays. Therefore, the efficacy profile of sunscreens defines the deepness where biological events induced by sunlight take place. This new relationship pinpoints the tremendous importance of the protection afforded by sunscreen products in the UVA range when erythema is taken as biological response. By extrapolation of the model to any other biological skin response it becomes possible to predict how to improve the efficiency of sunscreen products in the future. UVA protection afforded by sunscreens should be improved until reaching the same level as the SPF protection factor so that all UV-induced biological responses could be prevented or lowered at the same extend. To enforce this improvement, a proposal to classify sunscreen products in relation with their UVA protection is made.

Are Broad-Spectrum Sunscreens Necessary for Immunoprotection?

Are Broad-Spectrum Sunscreens Necessary for Immunoprotection?

Protection against UV-induced suppression of contact hypersensitivity responses by sunscreens in humans.

Both in vivo skin immune responses and the skin's reaction to sun exposure integrate a complex interplay of biologic responses. The complexity and multiplicity of events that occur in the skin during an immune response make it a sensitive indication of both UVB and UVA-induced changes in the skin by sun damage, as well as those changes that are prevented by various sunscreens. Sunscreens are the most effective and widely available intervention for sun damage, other than sun avoidance or clothing. However, sunscreens vary widely in their relative ability to screen various UV waveband components, and their testing has been variably applied to outcomes other than for erythema to determine the sunburn protection factor (SPF), a measure primarily of UVB filtration only. Determination of an immune protection factor (IPF) has been proposed as an alternative or adjunctive measure to SPF, and recent studies show IPF can indeed detect added in vivo functionality of sunscreens, such as high levels of UVA protection, that SPF cannot. Clarification of the definition of IPF, however, is required. Excellent data are available on quantification of the IPF for restoring the afferent or induction arm of contact sensitivity, but other immune parameters have also been measured. Proposed here is nomenclature for whether the IPF is measured using contact sensitivity induction (IPF-CS-I), contact sensitivity elicitation (IPF-CS-E), delayed-type hypersensitivity elicitation (IPF-DTH-E), antigen-presenting cell function (IPF-APC-FXN) or numbers (IPF-APC-#), and cytokine modification such as IL-10 (i.e. IPF-cyto-IL-10). Similar nomenclatures could be used for other measures of skin function protection (i.e. DNA damage, p53 induction, oxidation products, etc.). A review of in vivo human studies, in which sunscreens are used to intervene in a UV-induced modulation of immune response, cells or cytokines, highlights the technical variables and statistical approaches which must also be standardized in the context of an IPF for regulatory or product claim purposes. Development of such IPF standards would allow the integration of both UVB and nonUVB (UVA, blue and possible IR) solar waveband effect-reversals, could be applied to integrate effects of other ingredients with protective function (i.e. antioxidants, retinoids, or other novel products), and would spur development of more advanced and complete protection products.

017������Evaluation of the ���NASA��� garment for children with xeroderma pigmentosum

In the early 1990s NASA scientists developed a UV protective garment resembling a space suit for children afflicted with xeroderma pigmentosum. This garment together with gloves and face shield is able to protect the child allowing outdoor activities. We have examined all components of the garment within the framework of testing procedures developed for UV protective clothes and fabrics. The result is the garment developed more than 10 years ago meets today's standards for UV protective garments. Since photosensitive individuals, in general, may be affected by non-erythemogenic wavelengths, clothing for these patients require strategies not obvious for sunburn protection of normal individuals. These needs will be examined and recommendations made.

Influence of wetness on the ultraviolet protection factor (UPF) of textiles: in vitro and in vivo measurements.

Clothing is an important product for sunburn protection and skin cancer prevention. The moisture content of a fabric, which can increase during its wearing, may decrease the fabric's capability of protecting the skin from solar UV radiation, that is, lower its UPF (ultraviolet protection factor). Due to limited data about the effect of fabric wetness on UPF, this study was undertaken to investigate the following: (a) the effect of saturating a variety of fabrics with tap water and with salt water on fabric UPF and (b) whether wetted-fabric UPF values reflect only the fact that the fabric is wet during testing or the fact that the skin is hydrated and the fabric is wet. For objective a, 69 summer fabrics were spectrophotometrically (in vitro) assessed when "dry" and when saturated with tap and salt water. In vitro UPFs, percent UVA transmission and percent UVB transmission values were calculated from the transmission data. For objective b, 100% cotton and 100% polyester fabrics were tested in vivo to determine in vivo UPF values. The minimal erythema dose (MED) was determined for each of the 12 subjects on unprotected "dry" skin and on "hydrated" unprotected skin. MEDprotected was determined when the subject's skin was covered with "dry" and with saturated fabric. In vivo UPFs were calculated using this data. Student's paired t-tests were used to determine the effect of wetting. With one exception, in vitro UPF values were the same when the fabrics were saturated with tap water and when they were saturated with salt water. However, saturating the fabrics with water had different effects on the UPF, UVA transmission, and UVB transmission values. For linen, viscose and polyester fabrics, UPF significantly increased. For the cotton fabrics and the polyester + TiO2 fabrics, UPF significantly decreased. For the modal + TiO2 fabrics and the polyester crepe + TiO2 fabrics, UPF significantly increased. From the in vivo testing, the MED of the "hydrated unprotected" skin was not different than the MED of "dry unprotected skin." Values obtained from subtracting dry-fabric in vivo UPF values from dry-fabric in vitro values and subtracting wet-fabric in vivo UPF values from wet-fabric in vitro values are not different. Fabrics do not need to be tested when saturated with tap and with salt water. Testing fabrics wet and dry should be done, as the effect of saturating fabric on UPF value varies. Fortunately, UPF values for wetted fabrics reveal only the effect of increased moisture content in the fabric and have nothing to do with wetting of the skin by the fabric.

Sunscreens and cutaneous malignant melanoma: an Italian case-control study.

The possible relation between use of sunscreens and the risk of cutaneous malignant melanoma (CMM) was investigated in a case-control study conducted in 27 Italian centres on 542 incident, histologically confirmed cases and 538 controls admitted for acute, other than neoplastic or dermatologic conditions. Compared with subjects reporting never sunscreen use, the multivariate odds ratios (OR), after allowance for age, sex, geographic area, education, skin, eye and hair colour, freckles, number of naevi, history of sunburns, tanning pattern and duration of sunny vacations, were 0.97 (95% confidence interval [CI] 0.69 to 1.35) for those reporting "sometimes" and 0.80 (95% CI 0.54 to 1.17) for those reporting "often " sunscreen use. With reference to type of product most frequently used, the ORs were 0.96 (95% CI 0.52 to 1.77) for minimal, 0.90 (95% CI 0.63 to 1.28) for moderate and 1.41 (95% CI 0.85 to 2. 35) for high sunburn protection factor. With reference to duration of use, the OR was 0.86 (95% CI 0.58 to 1.29) for use started since >/=20 years. None of the corresponding trends in risks were significant. The ORs for sunscreen use were similar across strata of major identified covariates and, if anything, tended to decline after multivariate analysis. The present findings confirm that sunscreen use, as currently adopted in Italy, is not appreciably related to subsequent CMM risk.

The sun-protection factors of wet and dry T-shirts

The sunburn protection factors (SPF) of dry and wet samples of two white T-shirt materials were experimentally determined by measuring the spectral transmission of solar radiation through the materials. The dry and wet SPF’s were, respectively: 15 and 5 for 100% cotton, and 19 and 17 for 35% cotton/65% polyester.

An all-day test for the evaluation of a topical sunscreen

In order to examine the relevance of high sun protection factors (SPF) to medically important sunburn protection under natural exposure conditions, an all-day testing procedure using twenty-four sun-sensitive subjects was designed. Three small test areas above each scapula were used to compare sunscreen lotions with SPFs of 17 and 6 to a vehicle-treated site. In addition, all of the sun-exposed glabrous skin areas were treated with the highest SPF lotion. One side of each subject's torso and face was also retreated during the exposure period. The subjects were exposed to approximately fifteen times the minimal erythemal dose of ultraviolet B (UVB) during the test, and all received essentially complete protection with the SPF 17 lotion. No difference was seen between one and two applications. On the small test sites, both the SPF 17 and SPF 6 lotions provided protection from sunburn; however, the SPF 17 lotion provided significantly better protection than the SPF 6 lotion. Importantly, tanning was produced without associated or preceding redness, and these tanned areas persisted for 2 weeks or more. It was concluded that under natural exposure conditions when the integrity of the sunscreen film has not been compromised, a single application of the highest SPF sunscreen can protect sun-sensitive subjects from sunburn during a day-long sun exposure and that this protection is better than that afforded by a sunscreen with a substantially lower SPF.

Sunburn protection by longwave ultraviolet radiationinduced pigmentation

Sunburn protection by longwave ultraviolet radiationinduced pigmentation

Sunburn Protection by Longwave Ultraviolet Radiation-Induced Pigmentation

The role of melanin pigment in sunburn protection was investigated. Deep tans were induced over the backs of volunteers with repeated exposure to longwave ultraviolet radiation (UV-A). Melanogenesis was stimulated without an appreciable thickening of the stratum corneum. Two to three times the minimal erythema dose was required to produce redness in UV-A-tanned skin. Transmission studies through isolated corneum sheets revealed that specimens from tanned skin were about twice as efficient in filtering sunburn rays as stratum corneum from untanned skin. Tanning with UV-A does not provide a substantial resistance against sunburn.

Sunburn protection by longwave ultraviolet radiation-induced pigmentation

Sunburn protection by longwave ultraviolet radiation-induced pigmentation

Sweat‐ and water‐resistant sunburn preparations

No preparation having the properties of an ideal sunburn preventive is available and none has been produced, but an approach to it has been made. Of some 100 formulations tried, a bentonite clay ointment, a stearate mixture base ointment, a vanishing cream, and an ethocel lotion, nearly all containing homomenthyl salicylate and in some cases also ethyl p‐aminobenzoate as sunscreens and titanium dioxide as the pigment proved most satisfactory. The value of the ointments in sunburn protection was tested by comparing the ratio of the dosage required in the control patch of skin. Sweating and washing with water decrease the protective value of the ointments but not as much as in the case of commercial ointments tried. The formulas for the new preparations are given in full.

The vitamin content of chow mein

Whatever the improvement in the protection spectrum of sunscreens (SCs), actual skin protection mainly depends on the way they are used, especially on the quantity applied. This prospective randomized study assessed how much sun protection factor (SPF) labeling, which is hardly understandable by a layman, and high cost account for misuse of SCs. In three beach resorts in France, 364 individuals were blindly randomized during their holidays to three arms (1) free SCs intervention (FS)=four types of SCs with their usual SPF label (60B-A, 20B-A, 12B-A, 6B-3A) at free disposal; (2) same free SCs with an explicit labeling (FNL), including sunburn protection, likely protection against long-term effects of UV, and possibility to get a tan; and (3) no intervention (NI). As compared to FS, FNL increased the quantity of SCs applied, mainly in the minority of people who were not “tan-seekers”, reduced sunburns particularly in sun-sensitive individuals (25.6 vs 58.3%, P=0.005), and induced a shift in the level of SCs chosen. Free delivery SCs were associated with a more systematic application of SCs in case of exposure, and a decreased sunburn occurrence, without increase of exposure. These results suggest that a labeling more explicit for the public would result in a better protection in SC users and that cost could be a limiting factor to use SC as often as necessary.

Prevent sunburn by taking iron

Whatever the improvement in the protection spectrum of sunscreens (SCs), actual skin protection mainly depends on the way they are used, especially on the quantity applied. This prospective randomized study assessed how much sun protection factor (SPF) labeling, which is hardly understandable by a layman, and high cost account for misuse of SCs. In three beach resorts in France, 364 individuals were blindly randomized during their holidays to three arms (1) free SCs intervention (FS)=four types of SCs with their usual SPF label (60B-A, 20B-A, 12B-A, 6B-3A) at free disposal; (2) same free SCs with an explicit labeling (FNL), including sunburn protection, likely protection against long-term effects of UV, and possibility to get a tan; and (3) no intervention (NI). As compared to FS, FNL increased the quantity of SCs applied, mainly in the minority of people who were not “tan-seekers”, reduced sunburns particularly in sun-sensitive individuals (25.6 vs 58.3%, P=0.005), and induced a shift in the level of SCs chosen. Free delivery SCs were associated with a more systematic application of SCs in case of exposure, and a decreased sunburn occurrence, without increase of exposure. These results suggest that a labeling more explicit for the public would result in a better protection in SC users and that cost could be a limiting factor to use SC as often as necessary.