IMPORTANCE UV radiation (UVR) exposure is the primary environmental risk factor for developing cutaneous malignant melanoma (CMM). OBJECTIVE To measure changes in sun behavior from the first until the third summer after the diagnosis of CMM using matched controls as a reference. DESIGN, SETTING, AND PARTICIPANTS Three-year follow-up, observational, case-control study performed from May 7 to September 22, 2009, April 17 to September 15, 2010, and May 6 to July 31, 2011, at a university hospital in Denmark of 21 patients with CMM and 21 controls matched to patients by sex, age, occupation, and constitutive skin type participated in the study. Exposure to UVR was assessed the first and second summers (n=20) and the first and third summers (n=22) after diagnosis. Data from 40 participants were analyzed. MAIN OUTCOMES AND MEASURES Exposure to UVR was assessed by personal electronic UVR dosimeters that measured time-related UVR in standard erythema dose (SED) and corresponding sun diaries (mean, 74 days per participant each participation year). RESULTS Patients' daily UVR dose and UVR dose in connection with various behaviors increased during follow-up (quantified as an increase in daily UVR dose each year; all days: mean, 0.3 SED; 95% CI, 0.05-0.5 SED; days with body exposure: mean, 0.6 SED; 95% CI, 0.07-1.2 SED; holidays: mean, 1.2 SED; 95% CI, 0.3-2.1 SED; days abroad: 1.9 SED; 95% CI, 0.4-3.4 SED; and holidays with body exposure: mean, 2.3 SED; 95% CI, 1.1-3.4 SED). After the second year of follow-up, patients' UVR dose was higher than that of controls, who maintained a stable UVR dose. No difference was found between groups in the number of days with body exposure or the number of days using sunscreen in the second and third years of follow-up. CONCLUSIONS AND RELEVANCE Our findings suggest that patients with CMM do not maintain a cautious sun behavior in connection with an increase in UVR exposure, especially on days with body exposure, when abroad, and on holidays.
Since 1990 7 sunscreen allergens have been included in the standard photopatch protocol at 2 Swedish dermatology clinics. 355 consecutive patients with suspected photosensitivity were tested, and in 28 of these (7.9%), a total of 42 allergic reactions were found. 80% of the reactions were of photocontact origin. The most common allergen was benzophenone-3 (Eusolex 4360), with 15 photocontact and 1 contact allergic reactions, followed by isopropyl dibenzoylmethane (Eusolex 8020) (8 photocontact, 4 contact) and butyl methoxydibenzoylmethane (Parsol 1789), with 6 photocontact reactions. There were 2 cases of photocontact allergy to phenylbenzimidazole sulfonic acid (Eusolex 232), which has not been reported previously. 1 case of contact urticaria from benzophenone-3 was accidentally found. In addition, 21 + reactions of doubtful relevance were noted in 14 patients: 16 on irradiated and 5 on non-irradiated test sites. Among these, irritant and phototoxic reactions may be included. These results indicate that the inclusion of UV filters in the standard photopatch protocol is important. Immediate-type testing for urticaria could also be of value.
As the cost of air travel has decreased substantially in the USA and Europe over the past few decades, leisure travel to vacation destinations during the winter months has expanded significantly. This trend has probably increased the incidence of significant ultraviolet radiation exposure and sunburn in a broader population who could not previously afford this kind of travel. The purpose of this study was to analyse the correlation between increasing accessibility to air travel and melanoma incidence. This ecological study surveyed air travel patterns and melanoma incidence over the past three decades. Melanoma age-adjusted incidence was obtained from the United States Surveillance, Epidemiology, and End Results 9 Registry Database, 1975-2000, and the Cancer Registry of Norway, 1965-2000. United States mean inflation-adjusted airfare prices for four airports linked to leisure destinations (Miami, Los Angeles, San Diego, Phoenix) were compared with melanoma incidence. Parallel analyses were performed using annual domestic passenger-kilometres and melanoma incidence in Norway. Declining United States leisure-specific airfares corresponded strongly with increasing melanoma incidence (r = 0.96, r = 0.92, P
Quantitative analysis of threshold limit levels of UV-irradiation in the workroom environment established in USA, Netherlands and Russia was made. Comparison of its results with modern information about effective doses and action spectra of UV-radiation biological action allowed to reveal essential differences in the approach to rate setting and in some cases presence of internal contradictions and exceeding of threshold limit levels of UV irradiation above biologically effective values. The possibility of workroom UV standards utilisation for regulation of nature UV-radiation exposures was considered.
To determine the aetiology of spheroidal degeneration of the cornea (Labrador keratopathy), total population surveys were conducted in 5 communities in coastal Labrador and northern Newfoundland. For 4 years records were also kept on all clinic patients aged 40 or more throughout the region. Both methods gave a peak prevalence at latitudes 55 degrees--56 degrees north. The greatest severity and earliest age of onset occurred around the same latitudes. Of the proposed environmental causative agents only ultraviolet radiation, reflected from ice and snow, explains the distribution of the disease. The high cumulative UV dosage is due to the unique geographical and climatic features of the region.
Photoallergic contact dermatitis (PACD) is a hypersensitivity reaction that occurs when a previously photosensitized exogenous agent comes into contact with UV radiation. Currently, there are no studies profiling photoallergic reactions in Canada. Because the photoallergen profile changes over time, it is necessary to continually update our knowledge to ensure proper recognition of allergens and appropriate treatment of patients.
This study aimed to profile photoallergic reactions in Canada.
A retrospective chart review of all patients who underwent photopatch testing at Toronto Western Hospital between January 2001 and December 2010 was completed. Photoallergic, allergic, and irritant reactions were recorded for 26 common allergens.
Ninety-nine patients (61.9%) had at least 1 positive reaction to the test allergens. Fifty-four patients (33.8%) had at least 1 photoallergic reaction. All 26 allergens produced at least 1 allergic or photoallergic reaction. The most common relevant photoallergens were benzophenone-3, octyl dimethyl para-aminobenzoic acid (PABA) in 5% alcohol, and butylmethoxy-dibenzoylmethane.
This study is the first to profile photoallergic contact reactions in Canada. It is clear that the culprit photoallergen in PACD can often be identified in a properly selected population. Future surveillance is necessary to continue to characterize PACD trends in Canada and to help better treat and screen this patient population.
The risk of non-melanoma skin cancer in northern Europeans who indulge in sunbathing or use a UVA solarium was estimated using a mathematical model of skin cancer incidence that makes allowance for childhood, occupational and recreational sun exposure. This model demonstrates that the cumulative incidence of skin cancer in indoor workers is about 2-3% by the age of 70, yet this risk can increase 5-fold if they indulge in a two-week sunbathing vacation each summer. The use of a UVA solarium is also shown to increase the risk of skin cancer. Because risk increases with the approximate square of annual solarium exposure, it is not possible to define a 'safe' level of exposure. Instead, it is shown that weekly use of a UVA solarium from age 20 until middle age (40-50) gives a relative cumulative incidence of 1.3 compared with non-users of sun beds and sun canopies. The risk begins to increase rapidly for more frequent use, particularly when solaria are used in combination with sunbathing.
Ultraviolet B (UVB) irradiation causes skin damage and inflammation by inducing the secretion of various cytokines, which are immune regulators produced by cells. To prevent skin inflammation, keratinocytes that have been irreversibly damaged by UVB must be eliminated through apoptosis. Ixeris dentata (I.?dentata) (family Asteraceae) is a perennial medicinal herb indigenous to Korea. It is used in Korea, China and Japan to treat indigestion, pneumonia, diabetes, hepatitis, contusions and tumors. Guaiane-type sesquiterpene lactones were isolated from the whole extract of I.?dentata. This led to the isolation of the anti-inflammatory sesquiterpene lactone compound tectroside (TES), which was tested on a human keratinocyte cell line. To determine the anti-inflammatory effects of TES, we examined its influence on UVB-induced pro-inflammatory cytokine production in human keratinocytes (HaCaT cells) by observing these cells in the presence or absence of TES. In the present study, pro-inflammatory cytokine production was determined by performing enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction and western blot analysis to evaluate the activation of mitogen-activated protein kinases (MAPKs). TES inhibited UVB-induced production of the pro-inflammatory cytokines interleukin (IL)-6 and IL-8 in a dose-dependent manner. In addition, TES inhibited the expression of cyclooxygenase (COX)-2 and the phosphorylation of c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) MAPKs, suggesting that it inhibits the secretion of the pro-inflammatory cytokines IL-6 and IL-8 and COX-2 expression by blocking MAPK phosphorylation. These results suggest that TES can potentially protect against UVB-induced skin inflammation.
Although solar radiation is well established as a risk factor for melanoma, it is less clear how the pattern and timing of exposure to ultraviolet (UV) radiation might be important. The particular objective of this study was to evaluate the association of melanoma risk with various measures of intermittent and chronic exposures to UV radiation, and to assess how these exposures interact with other risk factors such as skin type.
Data were analysed from a large case-control study (583 cases, 608 controls) of malignant melanoma, carried out in southern Ontario, Canada.
Significant risk increases were identified with several measures of intermittent exposure, including beach vacations in adolescence and in the past 5 years, previous sunburn, and use of sunbeds and sunlamps. Chronic exposure, indicated by days of outdoor activity during adolescence and by occupation in recent adult life, was associated with significantly reduced risk. Subgroup analyses showed: no major risk differences by body site of melanoma; stronger association of lentigo maligna melanoma with intermittent exposure; more pronounced effects of beach vacations and sunburn in younger subjects; and consistently higher risks for intermittent exposures among subjects with skin more susceptible to burning.
The data lend limited support to the hypothesis of increased risk associated with intermittent UV exposure. The findings suggest that future studies should take age at diagnosis, host susceptibility and histological subtype into account.