Development of the multispectral UV polarization reflectance imaging system (MUPRIS) for in situ monitoring of the UV protection efficacy of sunscreen on human skin.

BACKGROUND: Protection of the human skin from ultraviolet (UV) damage is one of the main issues in dermatology and cosmetology. The UV protection efficacy (UVPE) of the sunscreen film is decreased by sweat, sebum, and friction during the day. However, the technical relationship between the UVPE evaluated in a laboratory and the actual protection in daily use has not been clarified, because the UVPE measurement method in real-life setting has not been established. This study aimed to develop a novel UVPE evaluation system that allows in situ monitoring of the UVPE in real-life activities. METHODS: The multispectral UV polarization reflectance imaging system (MUPRIS) and a UVPE estimation algorithm were developed. The diffuse reflectance spectra were measured for a total of 48 sunscreen materials that were applied on 59 subjects. The UVPEs estimated from the diffuse reflectance spectra were compared with the in vivo SPFs. Finally, the UVPE before and after a marine leisure activity was evaluated using the MUPRIS as the practical use test. RESULTS: Compared with the conventional UV camera, the MUPRIS could visualize the applied sunscreen more clearly and showed good UVPE estimation accuracy (correlation coefficient for in vivo SPF, 0.82). In the practical use test, the degradation of the UVPE during a marine leisure activity was quantitatively monitored and was validated by the actual occurrence of sunburn. CONCLUSIONS: A novel in situ UVPE monitoring tool had been successfully developed. It can strongly support the development of innovative sunscreen products that can perfectly protect customers against UV irradiation in real-life situation.

Appearance-based vs health-based sun protective messages: A randomized, double-blind controlled study.

BACKGROUND: Appearance-based messages have shown promise in improving sun protection habits among Caucasians but have scarcely been investigated in Hispanic populations. OBJECTIVE: To compare the effectiveness of appearance-based vs health-based messages in an ethnic patient population, where hyperpigmentation disorders are prevalent and often cosmetically concerning. METHODS: One hundred thirty-seven patients were randomized to receive images of (a) skin cancer, (b) hyperpigmentation, or (c) wrinkles. Analysis of variance tests for repeated measures were used to estimate the effects of the different stimuli on participants' knowledge and intention to sun protect. RESULTS: Appearance-based interventions were more effective in improving intentions to sun protect among both Hispanics and non-Hispanic Whites (P < 0.05). They were furthermore more effective among younger patient populations (≤40 years old) and patients who thought that a tanned appearance is attractive (P < 0.05). CONCLUSIONS: Appearance-based photos of sun damage were more effective than health-based messages among Hispanics, younger patient populations, and those who find tanned appearances to be attractive.

Conjunctival Ultraviolet Autofluorescence as a Measure of Past Sun Exposure in Children.

Background: Conjunctival ultraviolet autofluorescence (CUVAF) area detected from UVAF photographs is a recently developed potential marker for past sun exposure, but its relationship with sun-related factors has not been fully investigated.Methods: The study included 339 healthy children ages 5 to 15 years in Melbourne, Australia. Data were collected by questionnaire and examination at school. CUVAF area was measured using a computer program and analyzed as a continuous and dichotomous outcome (any/none).Results: Fifty-three children (15.6%) had detectable CUVAF, and the youngest age at which a child showed sun damage was 8 years. Compared with silicone skin cast score, there was good inter-grader agreement on CUVAF grading, with Cohen kappa 0.85 [95% confidence interval (CI), 0.65-1.00] for total CUVAF area using both eye photographs. Perfect intra-grader agreement was achieved. Fairer pigmentation, including medium/fair skin color [adjusted odds ratio (AOR), 3.42; 95% CI, 1.02-11.48 vs. dark/olive] and blue/gray eye color (AOR, 4.07; 95% CI, 1.73-9.55 vs. brown) was associated with increased odds of CUVAF. Increasing lifetime sunburn number (e.g., AOR, 2.89; 95% CI, 1.14-7.35 and 4.29; 1.04-17.76 for sunburns 2 to 4 and ≥ 5 times, respectively, vs. no sunburns, trend P = 0.004) and freckling by the end of last summer were associated with increased odds of CUVAF.Conclusions: CUVAF area can be an a priori objective measure of past sun exposure in pediatric populations for future research.Impact: To our knowledge, this is the first pediatric study that evaluated associations of sun-related risk factors with CUVAF. Cancer Epidemiol Biomarkers Prev; 26(7); 1146-53. ©2017 AACR.