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.

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.