Interdependence between body surface area and ultraviolet B dose in vitamin D production: a randomized controlled trial

Background Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25‐hydroxyvitamin‐D₃ [25(OH)D], but the relationship to body surface area and UVB dose needs investigation. Objective To investigate the importance of body surface area and UVB dose on vitamin D production after UVB exposure. Methods We randomized 92 participants to have 6%, 12% or 24% of their skin exposed to 0·75 (7·5 mJ cm^?2 at 298 nm using the CIE erythema action spectrum), 1·5 (15 mJ cm^?2) or 3·0 (30 mJ cm^?2) standard erythema doses (SED) of UVB. Each participant underwent four UVB exposures at intervals of 2–3 days. Skin pigmentation and 25(OH)D levels were measured before and 48 h after the final exposure. Results The increase in 25(OH)D after irradiation [Δ25(OH)D] was positively correlated with body surface area (P = 0·006; R² = 0·08) and UVB dose (P < 0·0001; R² = 0·28), and negatively correlated with baseline 25(OH)D (P < 0·0001; R² = 0·18), for the entire data sample. However, when analysing each body surface area separately, we found a significant UVB response correlation for 6% (P < 0·0001; R² = 0·48) and 12% (P = 0·0004; R² = 0·35), but not for 24%. We also found a significant skin area response correlation for 0·75 SED (P < 0·0001; R² = 0·56), but not for 1·5 and 3·0 SED when analysing each UVB dose separately. The relationships did not change significantly after adjustment of Δ25(OH)D for baseline 25(OH)D. Conclusion The increase in 25(OH)D depends mainly on the UVB dose; however, for small UVB doses the area of irradiated body surface is important.     

The effect of sunscreen on vitamin D: a review

Vitamin D is essential for bone health and is produced by the skin in response to ultraviolet radiation (UVR) from sunlight. UVR is also the main cause of skin cancer, the UK's most common type of cancer. Therefore, there have been several concerns that sun protection methods such as using sunscreen can affect vitamin D production. Researchers from the QIMR Berghofer Medical Research Institute in Australia, and the Australian National University, systematically reviewed for the first time all published experimental studies, field trials, and observational studies published between 1970 and 2017, totalling 75 studies, in order to understand the effect of sunscreen use on vitamin D levels. The researchers found that while the experimental studies (using artificial light sources in a laboratory setting) support the theoretical risk that sunscreen use may affect vitamin D, the weight of evidence from field trials and observational studies (taking place in real-life situations involving natural sunlight) suggests that the risk is low. The researchers explain that the conditions in the experimental studies did not reflect those of the real world, so the results cannot be used to inform practical recommendations for the public. The authors of this review concluded that there is little evidence that sunscreen, when used in real-life settings, decreases vitamin D levels and in some cases sunscreen use was associated with higher vitamin D levels. Therefore, concerns about vitamin D levels should not interfere with skin cancer prevention advice. Future trails should consider high sun protection factor sunscreens which are now widely recommended.     

A small suberythemal ultraviolet B dose every second week is sufficient to maintain summer vitamin D levels: a randomized controlled trial

Background It is known that ultraviolet (UV) B radiation increases serum 25‐hydroxyvitamin D₃ [25(OH)D] level. However, there is uncertainty about the relationship between the maintenance of vitamin D status and UVB. Objectives To define the frequency of UVB exposure necessary for maintaining summer 25(OH)D levels during the winter. Methods In total, 60 participants were included from October 2008 to February 2009 (16 weeks) and randomized for UVB exposure of 1 standard erythema dose (SED) to ～88% body area once a week (n = 15 completed), every second week (n = 14 completed) or every fourth week (n = 12 completed). The controls (n = 14 completed) had no intervention. Vitamin D was measured at baseline, every fourth week before exposure, and 2 days after the last UVB exposure. Results The 25(OH)D levels (mean) after UVB exposure once a week increased significantly (from 71·9 to 84·5 nmol L^?1) (P < 0·0001), whereas UVB exposure every second week maintained 25(OH)D levels (P = 0·16). A significant decrease in mean 25(OH)D levels (from 56·4 to 47·8 nmol L^?1) (P < 0·0001) was found after UVB exposure once every fourth week and for the control group (from 64·8 to 40·1 nmol L^?1) (P < 0·0001). The development in 25(OH)D levels during the 16‐week study period were negatively correlated with baseline 25(OH)D (P < 0·0001). Further, the increase in 25(OH)D after the last UVB exposure was negatively correlated with the 25(OH)D level just before the last UVB exposure (P < 0·0001). Conclusions Exposure to a UVB dose of 1 SED every second week to ～88% body area is sufficient for maintaining summer 25(OH)D levels during the winter.     

Combination TL01 ultraviolet B phototherapy and topical calcipotriol for psoriasis: a prospective randomized placebo-controlled clinical trial

BACKGROUND: Previous studies have demonstrated the ultraviolet (UV)-sparing effect of combining topical calcipotriol with broadband UVB in the treatment of psoriasis. OBJECTIVES: To determine if the combination of narrowband TL01 UVB phototherapy and topical calcipotriol produces the same UVB-sparing effect. METHODS: This was a randomized, placebo-controlled, blinded clinical trial. Fifty psoriasis patients were recruited, 25 of whom were randomized into the active group who received TL01 phototherapy together with twice-daily application of calcipotriol cream 50 microg g(-1). The control group received TL01 phototherapy and twice-daily application of a topical emollient as placebo. TL01 phototherapy was given three times per week starting at 70% minimal erythema dose with 20% increments as tolerated for up to approximately 20 sessions. Patients were assessed using the Psoriasis Area and Severity Index (PASI) and Psoriasis Disability Index (PDI). They were evaluated at treatment sessions 8, 14 and 20, and followed up at 5 and 10 weeks post-treatment. Statistical analysis was performed using a two-tailed t-test. RESULTS: There were no significant differences in demographic characteristics and baseline PASI and PDI scores between the two groups. The mean PASI score declined significantly (P < 0.01) for both groups after treatment. The difference in mean PASI score reduction from baseline between the two groups was only significant during the first eight sessions, with a net reduction of 3.6 (95% confidence interval 1.0-6.2, P = 0.008) in the active group relative to the control group. The mean PDI score declined significantly (P < 0.05) for both groups, but there was no statistical difference in mean PDI score reduction between the two groups (P = 0.8) at the end of treatment. The mean cumulative UVB dose for the active group was significantly lower (P < 0.02) at 16 204 mJ cm-2 compared with 21 082 mJ cm-2 for the control group. CONCLUSIONS: We conclude that combining TL01 phototherapy with topical calcipotriol cream has a UVB-sparing effect.     

Comparison of narrowband ultraviolet B exposure and oral vitamin D substitution on serum 25-hydroxyvitamin D concentration

Summary Background A short course of narrowband ultraviolet B (NB‐UVB) exposures increases the serum 25‐hydroxyvitamin D [25(OH)D] concentration in patients with psoriasis and healthy subjects. Objectives To compare the effects of NB‐UVB and oral vitamin D substitution in healthy subjects in winter. Methods Healthy adult hospital employees and medical students were screened for serum 25(OH)D concentration. Those with 25(OH)D below 75 nmol L^?1 were randomly given either 12 NB‐UVB exposures or 20 μg of oral cholecalciferol daily for 4 weeks. The NB‐UVB exposures were given with a Waldmann UV 7001 cabin and the mean cumulative dose was 48·4 standard erythema doses. Serum 25(OH)D was measured before and after the treatments by radioimmunoassay. Results The baseline serum 25(OH)D concentrations were 52·9 ± 10·4 (mean ± SD) in the 33 NB‐UVB‐treated and 53·5 ± 12·7 nmol L^?1 in the 30 oral cholecalciferol‐treated subjects. The mean increase in serum 25(OH)D was 41·0 nmol L^?1 [95% confidence interval (CI) 34·8–47·2; P < 0·001] in the NB‐UVB group and 20·2 nmol L^?1 (95% CI 14·6–26·0; P < 0·001) in the cholecalciferol group. The difference between the two treatments was significant at 2 weeks (P = 0·033) and at 4 weeks (P < 0·001). One month after the treatments the 25(OH)D concentrations had increased further. Conclusions The present study shows that 12 NB‐UVB exposures given during 4 weeks increase serum 25(OH)D concentration significantly more than 20 μg of oral cholecalciferol daily. A short NB‐UVB course is an effective way to improve vitamin D balance in winter and the response is still evident 2 months after the course.     

The effect of maintenance narrow-band ultraviolet B therapy on the duration of remission for psoriasis: a prospective randomized clinical trial

BACKGROUND: Narrow-band (311 nm) UVB is an effective treatment modality for moderate to severe psoriasis. The effect of maintenance narrow-band UVB on the duration of remission is unknown. AIM: To determine whether maintenance narrow-band UVB affects the duration of remission. METHODS: After clinically significant improvement [defined as 75% reduction in the initial Psoriasis Area and Severity Index (PASI) = "PASI 75"], patients were randomly assigned to one of two groups, namely maintenance and no maintenance. The first group received 2 months of maintenance therapy; the second group received no further treatment. Both groups were followed up for 1 year. RESULTS: At the end of 12 weeks, 46 of 50 patients (92%) achieved "PASI 75". Of these 46 patients, 32 had plaque-type psoriasis and 14 had guttate-type psoriasis. The numbers of patients assigned to the maintenance and no maintenance groups were 22 and 24, respectively. At the end of the study, 12 of the 22 patients (55%) in the maintenance group and, by contrast, eight of the 24 patients (33%) in the no maintenance group were still in remission. When the patients in both groups were categorized according to the type of psoriasis, eight of 14 (57%) patients with plaque-type psoriasis in the maintenance group and, by contrast, three of 18 (17%) in the no maintenance group were still in remission. Although numerically significant, life-table analysis indicated no statistically significant difference for the probability of remaining in remission between maintenance and no maintenance groups. CONCLUSIONS: The results provide some evidence that maintenance narrow-band UVB may achieve longer remission durations for patients with plaque-type psoriasis.     

Treatment of chronic urticaria with narrowband ultraviolet B phototherapy: a randomized controlled trial

Data regarding narrowband ultraviolet B (NB-UVB) phototherapy in patients with chronic urticaria is limited. The aim of this open, controlled study was to determine whether NB-UVB is effective in treating urticaria in combination with antihistamin. A total of 81 patients with chronic urticaria were recruited, 48 of whom were randomized into the NB-UVB plus antihistamine group. The control group (n = 33) received only antihistamine. Patients were assessed using the urticaria activity score and a visual analogue score (VAS). The 2 groups were evaluated at the same time-points: at treatment sessions 10 and 20 and at follow-up 3 months post-treatment. The reduction in urticaria activity score and VAS was statistically significant (p < 0.05 for both groups). When comparing the groups, the mean urticaria activity score was significantly lower in the NB-UVB group at session 10 (22.6 vs. 27.3) and session 20 (17.4 vs. 20.7). Statistically significant differences were also noted in VAS between the 2 groups (p < 0.01) at 3 months post-treatment. We conclude that NB-UVB may be an effective complementary treatment for patients with chronic urticaria.     

Efficacy of sunscreen with photolyase or regular sunscreen associated with topical antioxidants in treating advanced photodamage and cutaneous field cancerization: a randomized clinical trial

BackgroundSeveral treatments are available for skin with advanced photodamage, which is characterized by the presence of actinic keratoses (AK).ObjectivesEvaluate the efficacy of using sunscreen with photolyase compared to regular sunscreen, as well as to compare the combination of a topical formulation of antioxidants versus placebo in the treatment of advanced photodamage.MethodsThis was a randomized, double-blind, factorial clinical trial. Participants with AKs on their forearms were randomized to apply regular sunscreen (SC) or sunscreen with photolyase (SC+P) on both forearms during the day. One of the forearms in each group was randomized again to receive topical antioxidants (AOx), and the other forearm received a placebo cream (both for night application). The four groups were SC/AOx, SC/placebo, SC+P/AOx, and SC+P/placebo. The duration of treatment was 8 weeks. Primary outcomes were total AK clearance, decrease in Forearm Photoaging Scale (FPS), and AK severity scores. Secondary outcomes were reduction in AK count, partial clearance rate, and safety.ResultsForty participants (80 forearms) were included. All groups showed significant improvement in outcomes at week eight. There were no significant differences between SC and SC+P for either outcome. AOx led to a significant reduction in AK count (22%; p < 0.05). Partial clearance was obtained in 18 (47.4%) forearms treated with AOx and in 9 (23.7%) treated with placebo (p < 0.05). All groups reduced the FPS score, without significant differences among them.Study limitationsShort interval of follow-up and absence of re-evaluation in the absence of treatment were limitations of the present study.ConclusionsThere is no difference in the treatment of advanced photodamage skin when comparing the use of sunscreen with photolyase and regular sunscreen, and topical antioxidants were more efficient in reducing AK count than placebo.     

Narrowband ultraviolet B phototherapy for patients with refractory uraemic pruritus: a randomized controlled trial

Background Pruritus is very common in uraemic patients, but the treatment remains challenging. Studies regarding narrowband ultraviolet B (NB‐UVB) phototherapy for uraemic pruritus are rare. Objectives To investigate whether or not NB‐UVB phototherapy is an effective treatment for uraemic pruritus. Methods We conducted a single‐blind, randomized, controlled trial for patients with refractory uraemic pruritus. The treatment group received NB‐UVB phototherapy three times per week for 6 weeks. The dose of NB‐UVB started from 210 mJ cm^?2 and was increased by 10% each time. The control group received time‐matched exposures to long‐wave UVA radiation. A visual analogue scale (VAS) score was evaluated weekly for pruritus intensity for 12 weeks. The characteristics of pruritus were also assessed by a questionnaire at baseline and after 6 weeks of phototherapy. Results Both the NB‐UVB and control groups had significant and comparable improvement in the pruritus intensity VAS scores during the period of phototherapy and follow‐up. Compared with the control group, the NB‐UVB group showed a significant improvement in the involved body surface area affected by pruritus (P = 0·006), but not in sleep quality. More detailed regression and estimating analysis revealed that the patients in the NB‐UVB group had lower pruritus intensity scores at week 6, week 10 and week 12. This may indicate a beneficial difference at certain time points, but the effect seems marginal. Conclusions NB‐UVB phototherapy does not show a significant effect in reducing pruritus intensity compared with a control group for refractory uraemic pruritus. Further studies are warranted.     

Sun exposure,skin lesions and vitamin D production: evaluation in a population of fishermen

Background: Exposure to UVR provides benefits related to vitamin D synthesis, but also causes harms, since UVB is considered a complete carcinogen. There is no definition of the level of sun exposure and the proportion of exposed body required for proper synthesis of vitamin D in the skin without causing it damage.Objectives: This study aims to analyze the sun exposure index, vitamin D levels and clinical changes in the skin caused by constant sun exposure in the fishermen population.Methods: It is a cross-sectional, observational and analytical study The sample consisted of fishermen and was calculated in 174 individuals. The questionnaire was applied, the dermatological examination was carried out and the examinations of calcidiol, parathyroid hormone, calcium and phosphorus were requested. Data were expressed as percentages. The comparative analysis was done through the Chi-square test, and the correlations were established through the Pearson's linear coefficient.Results: We observed that there was vitamin D deficiency in a small part of the cases (11.46%), and the frequency of diagnosis of skin cancer was 2.7% of the cases surveyed.Study limitations: The difficulty in categorizing the sun exposure index.Conclusion: The fact that fishermen expose themselves to the sun chronically and have been exposed to the sun for more than 15 years, between 21 and 28 hours a week, and without photoprotection, were indicative factors for protection against vitamin D deficiency. Chronic exposure to sun and high vitamin levels D may be indicative of protection of this population against skin cancer.     

Topical vitamin B12--a new therapeutic approach in atopic dermatitis-evaluation of efficacy and tolerability in a randomized placebo-controlled multicentre clinical trial

BACKGROUND: Vitamin B(12) is an effective scavenger of nitric oxide (NO). As the experimental application of a NO synthase inhibitor, N omega-nitro-L-arginine, led to a clear decrease in pruritus and erythema in atopic dermatitis, it would be reasonable to assume a comparable effect of vitamin B(12). OBJECTIVES: The efficacy and tolerability of a new vitamin B(12) cream as a possible alternative to current therapies was examined. METHODS: A prospective, randomized and placebo-controlled phase III multicentre trial, involving 49 patients was conducted. For the treatment duration of 8 weeks, each patient applied twice daily (in the morning and evening) the vitamin B(12)-containing active preparation to the affected skin areas of one side of the body and the placebo preparation to the contralateral side according to the randomization scheme. RESULTS: On the body side treated with the vitamin B(12) cream, the modified Six Area Six Sign Atopic Dermatitis score dropped to a significantly greater extent than on the placebo-treated body side (for the investigational drug 55.34 +/- 5.74 SEM, for placebo 28.87 +/- 4.86 SEM, P < 0.001). At the conclusion of the study, the investigator and patients awarded mostly a 'good' or 'very good' rating to the active drug (58% and 59%, respectively) and a 'moderate' or 'poor' rating to the placebo (89% and 87%, respectively). CONCLUSIONS: Topical vitamin B(12) is a new therapeutic approach in atopic dermatitis. These results document a significant superiority of vitamin B(12) cream in comparison with placebo with regard to the reduction of the extent and severity of atopic dermatitis. Furthermore, the treatment was very well tolerated and involved only very low safety risks for the patients.     

Treatment with 311-nm ultraviolet B enhanced response of psoriatic lesions in ustekinumab-treated patients: a randomized intraindividual trial

Background Treatment with the interleukin‐12/23 antibody ustekinumab produces a satisfactory response [i.e. 75% reduction in Psoriasis Area and Severity Index (PASI) compared with baseline (PASI 75)] in the majority of patients with moderate to severe chronic plaque‐type psoriasis. Objectives To determine whether concomitant 311‐nm ultraviolet (UV) B therapy can further enhance the response in patients with psoriasis treated with ustekinumab. Methods Ten patients (five women and five men; mean age 58 years, range 48–66) with moderate to severe plaque‐type psoriasis were treated with ustekinumab at a standard dosage of 45 or 90 mg subcutaneously depending on body weight (below or above 100 kg) at weeks 0 and 4. Within 2 days after ustekinumab initiation, the minimal erythemal dose (MED) was determined and suberythemal MED 311‐nm UVB‐based phototherapy was thereafter administered to one randomly selected body half (left or right, excluding the head) three times weekly for 6 weeks. Treatment response was monitored weekly in terms of half‐body PASI. Results Nine patients completed the study. Analysis of their data showed that 311‐nm UVB significantly accelerated the therapeutic response. At baseline (i.e. start of 311‐nm UVB therapy), the mean PASI was similar in both irradiated and unirradiated body halves (13·6 vs. 13·3). At week 6, however, it was lower on irradiated body halves (2·5 vs. 6·1). This difference of 3·6 (95% confidence interval 1·3–5) was statistically significant and corresponded to an overall mean PASI reduction from baseline of 82% vs. 54%, respectively. At week 6, PASI 75 was achieved significantly more often on UV‐irradiated body halves than on unirradiated body halves [7/9 patients (78%) vs. 1/9 (11%)] (McNemar test, P = 0·007). At week 12, this synergistic effect of 311‐nm UVB was still apparent although not significantly so. Conclusions Treatment with 311‐nm UVB accelerates the clearance of psoriatic lesions in ustekinumab‐treated patients.     

不同波长紫外线照射后皮肤颜色的变化

目的 观察不同波长紫外线照射皮肤后,颜色变化的过程。方法 用双倍剂量最小持续性黑化量和最小红斑量对10例Ⅲ型受试者皮肤进行照射,通过临床评分、扫描反射比分光光度仪和窄谱反射分光光度计三种方法对照射后的皮肤进行14天的评价和测定。结果 UVB照射后,a*值和红斑指数（EI值）在照射后6 h急剧增加,照射后2天达到高峰;L*值在照射后1天出现急剧降低;ITA°在第7天显著降低;黑素指数（MI值）在照射后2天内有逆向的降低趋势,直到照射后7天才有显著增高。在UVA照射下,a*值和EI值改变不明显;L*值在照射后6 h出现显著降低;ITA°在第14天达到最低值; MI值仅照射后1天有显著增高。结论 UVA和UVB照射后的皮肤颜色改变在时间动力学和反应程度方面有明显区别。a*值和EI值是评价照射后日晒伤较为敏感而准确的参数,而ITA°和MI值是评价晒斑较好的参数。