Retinoids in the treatment of photoageing: A histological study of topical retinoid efficacy in black skin.

BACKGROUND: Photoageing describes complex cutaneous changes that occur due to chronic exposure to solar ultraviolet radiation (UVR). The 'gold standard' for the treatment of photoaged white skin is all-trans retinoic acid (ATRA); however, cosmetic retinol (ROL) has also proven efficacious. Recent work has identified that black skin is susceptible to photoageing, characterized by disintegration of fibrillin-rich microfibrils (FRMs) at the dermal-epidermal junction (DEJ). However, the impact of topical retinoids for repair of black skin has not been well investigated. OBJECTIVES: To determine the potential of retinoids to repair photoaged black skin. METHODS: An exploratory intervention study was performed using an in vivo, short-term patch test protocol. Healthy but photoaged black volunteers (>45 years) were recruited to the study, and participant extensor forearms were occluded with either 0.025% ATRA (n = 6; 4-day application due to irritancy) or ROL (12-day treatment protocol for a cosmetic) at concentrations of 0.3% (n = 6) or 1% (n = 6). Punch biopsies from occluded but untreated control sites and retinoid-treated sites were processed for histological analyses of epidermal characteristics, melanin distribution and dermal remodelling. RESULTS: Treatment with ATRA and ROL induced significant acanthosis (all p < 0.001) accompanied by a significant increase in keratinocyte proliferation (Ki67; all p < 0.01), dispersal of epidermal melanin and restoration of the FRMs at the DEJ (all p < 0.01), compared to untreated control. CONCLUSIONS: This study confirms that topical ATRA has utility for the repair of photoaged black skin and that ROL induces comparable effects on epidermal and dermal remodelling, albeit over a longer timeframe. The effects of topical retinoids on black photoaged skin are similar to those reported for white photoaged skin and suggest conserved biology in relation to repair of UVR-induced damage. Further investigation of topical retinoid efficacy in daily use is warranted for black skin.

Prevalence and correlates of sun protections with sunburn and vitamin D deficiency in sun-sensitive individuals.

BACKGROUND: Sun sensitivity is an inherent risk factor for skin cancer. Sun protection is important in sun-sensitive individuals to reduce sunburns for skin cancer prevention. However, concerns have arose regarding the possible impact of sun protection on vitamin D deficiency. OBJECTIVE: To examine the prevalence and correlates of sun-protective behaviours (staying in the shade, using sunscreen and wearing long sleeves) with sunburn and vitamin D deficiency in sun-sensitive individuals. METHODS: This was a cross-sectional study of 2390 US non-Hispanic white adults aged 20-59 years in the National Health and Nutrition Examination Survey 2011-2014. Sun sensitivity was defined as self-reported tendency to severe sunburn when exposed to the sun for half an hour after months of non-sun exposure, and single serum 25(OH)D levels less than 50 nmol/L was determined as vitamin D deficiency. We calculated adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) using multivariable logistic regression taking into account the complex survey design. RESULTS: Sun-sensitive individuals had higher odds of frequently staying in the shade (aOR = 3.08; 95% CI 2.19-4.33) and using sunscreen (aOR = 1.93; 1.44-2.59) but not associated with sun exposure time (aOR = 0.91; 0.62-1.32). Yet, sun-sensitive individuals had significantly higher likelihood of sunburns (aOR = 1.93; 1.45-2.55), and no increased likelihood of vitamin D deficiency (aOR = 1.15; 0.84-1.58). Among sun-sensitive individuals, being younger, male and spending more time outdoors were associated with increased odds of sunburns and the risk of sunburn was reduced with frequently staying in the shade and engaging in multimodal sun protections. CONCLUSION: Sun-sensitive individuals more frequently used sun protection methods yet they still were significantly more likely to experience sunburns and the risk of vitamin D deficiency was not increased. Education on proper application of sunscreen combined with other sun-protective techniques is important to reduce sunburn in sun-sensitive populations.

Misinformation is prevalent in psoriasis-related YouTube videos.

Background Psoriasis patients seek information online, but little is known about their interaction with YouTube. We examined the quality of content in psoriasis-related YouTube videos and investigated their interactions with viewers.Methods YouTube was searched using the term "psoriasis." Relevant videos in English were independently categorized by two reviewers as useful, misleading, or patient view (regarding experience with psoriasis). Disagreements were settled by a third reviewer. Videos were rated on a Global Quality Scale (GQS) (1=poor, 5=excellent).Results According to our reviewers, 17% of the 47 videos were useful, 21% were misleading, and 62% represented patient views. Mean GQS scores were 4.2 ± 1.3 for useful videos, 1.7 ± 0.7 for misleading videos, and 2.2 ± 1.1 for patient view videos (p<0.001). Video views per day did not differ among the categories (p=0.65), whereas useful videos had fewest "Likes" (useful: 31 ± 55, 33 misleading: 151 ± 218, patient views: 165 ± 325, p=0.06) and comments (useful: 9.8 ± 18.3, misleading: 64.1 ± 89.7, 124.9 ± 34 199.4, p=0.009).Conclusions Useful videos were highest in quality but had similar viewership as misleading and patient view videos, with lower popularity and  engagement of users compared to other categories. Physicians and psoriasis patients should be aware of this pattern when pproaching YouTube as a resource.

Improving acne keloidalis nuchae with targeted ultraviolet B treatment: a prospective, randomized, split-scalp comparison study.

BACKGROUND: Acne keloidalis nuchae (AKN) is a chronic scarring folliculitis with fibrotic papules on the occipital scalp. Its treatment is limited and unsatisfactory. OBJECTIVES: To determine whether targeted ultraviolet B (tUVB) phototherapy will (i) improve the clinical appearance of AKN and (ii) induce extracellular matrix remodelling in affected lesions. METHODS: Eleven patients with AKN were enrolled in a prospective, randomized, split-scalp comparison study. One randomly selected side of the scalp was treated with tUVB up to three times weekly for 8 weeks. After week 8, both sides were treated for eight additional weeks. Assessment included lesion counts in two 3 × 3-cm regions of interest (ROIs), one on each side of the scalp (ROI-1: tUVB weeks 0-16, ROI-2: tUVB weeks 9-16), patient self-assessment and analysis of MMP1, MMP9, TGFB1 and COL1A1 mRNA expression by quantitative reverse-transcription polymerase chain reaction. RESULTS: Before treatment, the mean lesion count was similar between tUVB-treated and untreated sides (14·8 vs. 15·0). After 8 weeks of tUVB, the mean lesion count decreased significantly to 9·4 ± 1·2 (P =  0·03), with no change on the untreated side. With continued treatment, the mean lesion count in ROI-1 decreased further to 7 ± 1·5 (P = 0·04) after 16 weeks of tUVB. CONCLUSIONS: tUVB significantly improved the clinical appearance of AKN, led to patient satisfaction and was well tolerated.