Exploring Interaction between Genetically Predicted Body Mass Index and Serum 25-Hydroxyvitamin D Levels on the Odds for Psoriasis in UK Biobank and the HUNT Study: A Factorial Mendelian Randomization Study

Mendelian randomization (MR) studies show that higher body mass index (BMI) and lower 25-hydroxyvitamin D (25[OH]D) increase psoriasis risk. The combined effect of these factors has not been explored using factorial MR. Using cross-sectional data from UK Biobank (n = 398,404) and The Trøndelag Health Study (n = 86,648), we calculated polygenic risk scores for BMI and 25(OH)D to estimate ORs for psoriasis using 2 × 2 and continuous factorial MR. We quantified additive interaction by estimating relative excess risk due to interaction. We also performed traditional observational analyses in UK Biobank. There were 12,207 (3.1%) participants with psoriasis in UK Biobank and 7794 (9.0%) in The Trøndelag Health Study. In 2 × 2 factorial MR, we found no evidence of relative excess risk for psoriasis due to interaction between genetically predicted higher BMI and lower 25(OH)D, neither in UK Biobank (relative excess risk due to interaction = -0.01, 95% confidence interval = -0.08 to 0.07) nor in The Trøndelag Health Study (relative excess risk due to interaction = -0.04, 95% confidence interval = -0.14 to 0.06). The same was observed in the continuous factorial MR and observational analyses. In conclusion, this study did not find evidence of interaction between BMI and 25(OH)D on the risk of psoriasis. Given minor differences in measured BMI and 25(OH)D between the factorial groups, small effects may have been undetected.

Vitamin D: Beyond Traditional Roles-Insights into Its Biochemical Pathways and Physiological Impacts

Background: It is true that vitamin D did not earn its title as the "sunshine vitamin" for nothing. In recent years, however, there has been a shift in the perception surrounding vitamin D to a type of hormone that boasts countless bioactivities and health advantages. Historically, vitamin D has been known to take care of skeletal integrity and the calcium-phosphorus balance in the body, but new scientific research displays a much larger spectrum of actions handled by this vitamin. Materials and Methods: A systematic literature search was performed using the following electronic databases: PubMed, Scopus, Web of Science, Embase, and Cochrane Library. Results: Many emerging new ideas, especially concerning alternative hormonal pathways and vitamin D analogs, are uniformly challenging the classic "one hormone-one receptor" hypothesis. To add more context to this, the vitamin D receptor (VDR) was previously assumed to be the only means through which the biologically active steroid 1,25-dihydroxyvitamin D3 could impact the body. Two other molecules apart from the active hormonal form of 1,25(OH)2D3 have gained interest in recent years, and these have reinvigorated research on D3 metabolism. These metabolites can interact with several other nuclear receptors (like related orphan receptor alpha-RORα, related orphan receptor gamma-RORγ, and aryl hydrocarbon receptor-AhR) and trigger various biological responses. Conclusions: This paper thus makes a case for placing vitamin D at the forefront of new holistic and dermatological health research by investigating the potential synergies between the canonical and noncanonical vitamin D pathways. This means that there are now plentiful new opportunities for manipulating and understanding the full spectrum of vitamin D actions, far beyond those related to minerals.

Psoriasis: Unraveling Disease Mechanisms and Advancing Pharmacological and Nanotechnological Treatments

Research into the pathogenesis of inflammatory skin diseases, including dermatitis and psoriasis, has yielded significant advancements in the last decades. The identification of age, gender, and genetic factors contributing to these complex conditions has been pivotal in developing novel pharmacological and technological treatments. This review delves into the molecular underpinnings of psoriasis, examining current therapies and promising investigational agents. We highlight the potential of nanotechnology to enhance drug delivery to affected skin areas, with microneedles emerging as a promising platform for psoriasis and other chronic inflammatory skin diseases.

Unveiling the Link: The Potential Roles of Vitamin D in Keloid Pathophysiology

Keloid disease, a fibroproliferative skin disorder, is characterised by scar tissue growth that extends beyond the original wound boundaries. Despite advancements, current treatments, particularly surgical excision, often result in high recurrence rates, ranging from 45% to 100%. Recent investigations into the role of vitamin D (vit D) in keloids present a promising avenue for novel therapeutic strategies. Studies have highlighted the multifaceted involvement of vit D, including its immunomodulatory effects and influence on key processes such as fibroblast activity, collagen production and extracellular matrix dynamics. Additionally, emerging research has explored the potential impact of vit D on epithelial-to-mesenchymal transition and endothelial dysfunction, both of which are implicated in keloid formation and progression. This review consolidates the current evidence linking vitamin D deficiency to keloid pathogenesis, shedding light on potential mechanisms and therapeutic targets. By elucidating the intricate interplay between vit D signalling and keloid development, this study paves the way for innovative treatment approaches that may enhance patient outcomes and mitigate the burden of this challenging dermatological condition.

Differential Expression of Proteins Involved in Skin Barrier Maintenance and Vitamin D Metabolism in Atopic Dermatitis: A Cross-Sectional, Exploratory Study

Atopic dermatitis (AD) is a chronic inflammatory skin disorder influenced by proteins involved in skin barrier maintenance and vitamin D metabolism. Using an intra-patient design, this study compared protein expression in intra-lesional (IL) and peri-lesional (PL) skin biopsies from AD patients and examined associations between protein levels, vitamin D status, and clinical features. Forty-four biopsies from twenty-two AD patients were analyzed using antibody microarrays targeting twelve proteins. IL samples had significantly higher total protein levels than PL samples, with a mean difference of 77.7% (p < 0.001). Several proteins, including cathelicidin, cingulin, occludin, filaggrin, and the vitamin D receptor, were upregulated in IL samples. Patients with vitamin D levels below 30 ng/mL showed higher expression of CYP24A (p = 0.054), alpha-catenin (p = 0.043), and haptoglobin (p = 0.033). Increased EASI scores (≥16) were associated with elevated expression of CYP24A (p = 0.024), CYP27B (p = 0.044), filaggrin (p = 0.027), occludin (p = 0.049), and claudin-1 (p = 0.052). Multivariate regression analysis identified significant correlations between protein expression, skin prick test positivity, and low vitamin D levels. These findings suggest that proteins related to epithelial barrier function and vitamin D metabolism are highly upregulated in IL skin regions, offering potential therapeutic targets for improving both skin barrier function and overall disease severity in AD patients.

Relationship of vitamin D to pathogenesis and outcomes of hidradenitis suppurativa: a systematic review

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterized by painful sinus tracts and significant scarring. Recent evidence suggests that vitamin D deficiency may play a role in the pathogenesis and outcomes of HS. This systematic review aims to evaluate the relationship between vitamin D levels and HS, exploring potential therapeutic benefits of vitamin D supplementation. This systematic review followed PRISMA guidelines and was registered with PROSPERO (ID:CRD42024566092). A comprehensive literature search was conducted in PubMed, Medline (OVID), and Web of Science using the keywords "hidradenitis suppurativa" and "vitamin D." Studies were screened for relevance, and non-randomized studies were assessed for quality using the MINORS score. Due to the heterogeneity of clinical outcome measures, a qualitative analysis was performed. A total of 77 records were identified, with 38 articles remaining after duplicates were removed. After full-text screening, 8 studies met the inclusion criteria. These studies, published between 2014 and 2024, included case-control, cross-sectional, and cohort studies. High prevalence rates of vitamin D deficiency (75-100%) were consistently observed among HS patients. Improved clinical outcomes with vitamin D supplementation were noted in several studies. There were significant correlations between vitamin D deficiency and higher clinical severity, and genetic alterations in vitamin D metabolism and keratinization pathways were identified in HS patients. This systematic review demonstrates a significant association between vitamin D deficiency and HS. Vitamin D's role in immune regulation and anti-inflammatory processes suggests its potential as a therapeutic agent for HS. However, further research is needed to determine optimal dosing and assess the protective effects of vitamin D supplementation in HS management.

Association between dietary inflammatory index and all-cause mortality in US adults with dermatitis: a population-based cohort study

Background

While dermatitis management is primarily symptomatic, the role of diet in symptom exacerbation and improvement is increasingly recognized. The dietary inflammatory index (DII), a quantitative assessment tool for dietary inflammatory potential, has been associated with various chronic diseases but remains understudied in dermatitis. This cohort study investigated the association between DII scores and all-cause mortality among patients with dermatitis.

Methods

The study included 1,074 patients with dermatitis and complete dietary intake records from the National Health and Nutrition Examination Survey (NHANES) 1999-2004. The DII scores were calculated using two 24-h dietary recalls and dietary supplement intakes and the consumption of 28 foods with known pro- or anti-inflammatory properties. All-cause mortality information was from the National Death Index, censored on December 31, 2019. Multivariable Cox hazards regression models, restricted cubic spline (RCS) models, and subgroup analyses were employed to evaluate the association of DII with all-cause mortality, adjusting for potential confounders.

Results

The 1,074 patients were divided into DII tertiles (T1: n = 358, median age 40 years, DII -3.91, 0.06; T2: n = 296, median age 40 years, DII 0.06, 1.88; T3: n = 237, median age 39 years, DII 1.88, 4.39). The study revealed a positive correlation between higher DII scores and increased all-cause mortality risk among patients with dermatitis (fully-adjusted model, HR = 1.13, 95% CI 1.02, 1.27, p = 0.026). This association was more pronounced in adults over 45 years, with the highest DII tertile indicating a 2.42-fold increased mortality risk (95% CI 1.15, 5.07, p = 0.019) compared with the lowest tertile. The RCS model confirmed a linear dose-response trend (p for non-linear = 0.183), validating the relationship.

Conclusion

Elevated DII scores are associated with an increased risk of all-cause mortality in patients with dermatitis, suggesting that the dietary inflammatory potential may impact health outcomes in this population. The findings underscore the importance of dietary interventions in dermatitis management, especially for middle-aged and older adults. Future research with larger cohorts and a longer follow-up is warranted to validate the findings.

Nutrition, Obesity, and Seborrheic Dermatitis: Systematic Review

BACKGROUND

Pathogenesis of seborrheic dermatitis involves lipid secretion by sebaceous glands, Malassezia colonization, and an inflammatory response with skin barrier disruption. Each of these pathways could be modulated by diet, obesity, and nutritional supplements. Current treatment options provide only temporary control of the condition; thus, it is essential to recognize modifiable lifestyle factors that may play a role in determining disease severity.

OBJECTIVE

This study aimed to summarize published evidence on diet, nutritional supplements, alcohol, obesity, and micronutrients in patients with seborrheic dermatitis and to provide useful insights into areas of further research.

METHODS

A literature search of Scopus, PubMed, and MEDLINE (Ovid interface) for English language papers published between 1993 and 2023 was conducted on April 16, 2023. Case-control studies, cohort studies, and randomized controlled trials with 5 or more subjects conducted on adult participants (>14 years) were included, case reports, case series, and review papers were excluded due to insufficient level of evidence.

RESULTS

A total of 13 studies, 8 case-control, 3 cross-sectional, and 2 randomized controlled trials, involving 13,906 patients were included. Seborrheic dermatitis was correlated with significantly increased copper, manganese, iron, calcium, and magnesium concentrations and significantly lower serum zinc and vitamin D and E concentrations. Adherence to the Western diet was associated with a higher risk for seborrheic dermatitis in female patients and an increased consumption of fruit was associated with a lower risk of seborrheic dermatitis in all patients. The prebiotic Triphala improved patient satisfaction and decreased scalp sebum levels over 8 weeks. Most studies find associations between regular alcohol use and seborrheic dermatitis, but the association between BMI and obesity on seborrheic dermatitis severity and prevalence is mixed.

CONCLUSIONS

This review sheds light on specific promising areas of research that require further study, including the need for interventional studies evaluating serum zinc, vitamin D, and vitamin E supplementation for seborrheic dermatitis. The negative consequences of a Western diet, alcohol use, obesity, and the benefits of fruit consumption are well known; however, to fully understand their specific relationships to seborrheic dermatitis, further cohort or interventional studies are needed.

TRIAL REGISTRATION

PROSPERO CRD42023417768; https://tinyurl.com/bdcta893.

Association between Vitamin D Receptor Polymorphisms, Tight Junction Proteins and Clinical Features of Adult Patients with Atopic Dermatitis

INTRODUCTION

Few studies have explored the intricate connections between vitamin D receptor (VDR) gene polymorphisms, VDR, tight junction (TJ) protein expression and clinical features of atopic dermatitis (AD).

METHODS

From 43 adult AD patients, VDR polymorphisms were genotyped from peripheral blood samples using polymerase chain reaction-restriction fragment length polymorphism. VDR, occludin, claudin-1 and ZO-1 protein expression from skin lesion biopsies were assessed by immunohistochemistry.

RESULTS

The A1012G heterozygous VDR polymorphism exhibited a lower odds ratio (OR) for juvenile AD onset (OR: 0.046, 95% CI 0.004-0.51, p=0.012). In contrast, the presence of ≥2 homozygous VDR polymorphisms were significantly associated with positive skin prick test (SPT) (10/20, 50%) vs. negative SPT (1/23, 4.3%; p=0.0003). The most highly expressed TJ proteins in lesions of AD patients were claudin-1 and zonulin-1 (ZO-1), while VDR and occludin were less prevalent. A significant correlation was observed between ZO-1 expression and a body mass index ≥30 kg/m2 (OR: 12.1, 95% CI 1.06-137.9, p=0.045). Claudin-1 expression was associated with a positive SPT (OR: 8.23, 95% CI 1.04-65.5, p=0.046) and serum 25(OH)D levels were negatively correlated with ZO-1 expression (rho= -0.43, p=0.0058).

CONCLUSION

This study provides novel insights into the relationship between VDR gene polymorphisms, VDR, TJ protein expression, and clinical features in adult AD patients, highlighting a significant role of vitamin D in the pathophysiology of this disease.

Osteoporosis and bone health in pediatric patients with epidermolysis bullosa: A scoping review

Nutritional compromise, low levels of vitamin D, chronic inflammation, abnormal growth, and physical inactivity affect bone metabolism and compromise long-term bone health in individuals with epidermolysis bullosa (EB). The result is a high risk for osteopenia, osteoporosis, and pathologic fractures, but this important consequence of EB has been the focus of few investigations. Our scoping review found 21 publications that assessed the current understanding and clinical practices for monitoring of osteoporosis and its treatment in EB. Recommendations summarized from 13 of these publications include early nutritional and weight assessments before 2 years of age; bloodwork every 6-12 months starting at birth; Tanner stage assessments every 6 months to detect any pubertal delay; DEXA scans starting at age 6 years with repeated scans every 1-2 years, except in mild cases; and vitamin D supplementation of 80-320 IU daily for children 0-7 years and 720 IU for patients >8 years.

Safety and Efficacy of Topical Vitamin D in the Management of Dry Eye Disease Associated With Meibomian Gland Dysfunction: A Placebo-Controlled Double-Blind Randomized Controlled Trial

PURPOSE

The aim of this study was to investigate the safety and efficacy of topical vitamin D in the management of dry eye disease associated with meibomian gland dysfunction (MGD).

METHODS

In this randomized controlled trial, patients with symptomatic MGD were divided into 2 groups to receive topical vitamin D drops or placebo in their randomized eyes. The exclusion criteria consisted of patients with vitamin D deficiency, previous ocular surgery, and patients with ocular diseases affecting the tear film. Patients and researchers were masked to the study groups. The outcomes included the score of Dry Eye Questionnaire (DEQ) 5 and Ocular Surface Disease Index (OSDI), corneal and conjunctival staining score, tear breakup time (TBUT), Schirmer, and MG expressibility score evaluated at baseline and weeks 4 and 8.

RESULTS

Twenty-eight eyes of 28 patients were recruited in each group. In addition to the improvement of subjective parameters in both groups, there was a statistically significantly greater improvement in the vitamin D group compared with control for average scores of OSDI (13.38 ± 7.32 vs. 27.94 ± 7.49) and DEQ5 (9.67 ± 1.86 vs. 14.14 ± 2.45) at week 8 (Ps <0.001). In addition, a significant improvement in TBUT and Schirmer test was observed in both groups in weeks 4 and 8 ( P value <0.05). There was a significant difference between the treatment and control groups after 8 weeks for OSDI, DEQ5, Schirmer, TBUT, corneal fluorescein staining, and MG expressibility score ( P value <0.05).

CONCLUSIONS

The preliminary results of this randomized controlled trial suggested that use of topical vitamin D drops with a lipid vehicle could be safe and might significantly improve the symptoms and signs of dry eye associated with MGD.

The effect of vitamin D2 supplementation on vitamin D levels in humans: A time and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Inconsistencies exist regarding the influence of vitamin D2 (ergocalciferol) supplementation on serum vitamin D levels. These inconsistencies could be attributed to numerous factors, such as dosage, baseline vitamin D levels, and duration of intervention. Hence, this dose-response meta-analysis of randomized controlled trials was conducted to assess the efficacy of vitamin D2 supplementation on vitamin D levels.

METHODS

Relevant studies were searched in PubMed/Medline, Web of Science, Embase, and Scopus, from their inception to 3 January 2023. Variable alterations were considered to calculate the pooled weighted mean difference (WMD) with 95% confidence interval (CI) using the random effects model.

RESULTS

Pooled results from 33 study arms demonstrated that Vitamin D2 treatment significantly increases total vitamin D concentrations (WMD: 11.47 ng/mL, 95 %CI: 9.29 to 13.64, p < 0.001), 25(OH)D2 concentrations (WMD: 11.40 ng/mL, 95 %CI: 4.72 to 18.09, p = 0.001), and 1,25(OH)D concentrations (WMD: 5.61 ng/mL, 95 %CI: 0.74 to 10.48, p = 0.024), but decreases 25(OH)D3 concentrations (WMD: -4.63 ng/mL, 95 %CI: -6.46 to -2.81, p < 0.001). In subgroup analyses, increase in total vitamin D concentrations was more significant in vitamin D2 doses >2000 IU/day (WMD: 13.82 ng/mL), studies with duration ≤12 weeks (WMD: 12.53 ng/mL), participants aged ≥60 years (WMD: 14.40 ng/mL), and trials with basal 25(OH)D concentrations <20 ng/mL (WMD: 11.47 ng/mL).

CONCLUSIONS

This meta-analysis indicates that the supplementation of vitamin D2 significantly increases the serum concentrations of total vitamin D, 25(OH)D2, and 1,25(OH)D, but decreases 25(OH)D3 concentrations. Careful consideration of patient characteristics, dosage, and treatment duration is recommended for vitamin D2 supplementation.

The association between serum 25-hydroxyvitamin D levels and psoriasis in a large population-based cohort: a cross-sectional analysis of The Tromsø Study 2015-16

BACKGROUND

Case-control studies indicate an association between lower serum 25-hydroxyvitamin D [25(OH)D] levels and psoriasis. Data from larger population-based cohorts including mild cases are sparse.

OBJECTIVES

To investigate the association between 25(OH)D and psoriasis in a large population-based cohort, and assess possible effect modification by overweight.

METHODS

Data from the Tromsø Study 2015-16 (Tromsø7), which included 19 520 participants from the general population aged 40-79 years, were subjected to a cross-sectional analysis. We assessed the shapes of the relationships between 25(OH)D and psoriasis using fractional polynomials. Odds ratios (ORs) for lifetime and active psoriasis were estimated using logistic regression. Adjusted models included month of blood sampling, body mass index (BMI), age and sex. Two-way and additive interaction between BMI and 25(OH)D were explored.

RESULTS

From a total of 19 520 participants [10 203 women (52.3%); mean age 56.3 years (SD 10.4); mean 25[OH]D, 63.4 nmol L-1 (SD 21.9)], 2088 (10.7%) reported lifetime psoriasis and 1179 (6.0%) reported active psoriasis the past 12 months. There was no association between 25(OH)D and lifetime psoriasis [OR per 10 nmol L-1 increase in 25(OH)D 1.02, 95% confidence interval (CI) 0.99-1.04]. The relationship between 25(OH)D and active psoriasis was suggested to be nonlinear, but the model was not significant (P = 0.098). There was evidence for a superadditive effect (i.e. larger than the sum of the factors) of BMI > 27.5 kg m-2 and 25(OH)D < 25 nmol L-1 on the odds for active psoriasis (OR 1.92, 95% CI 1.18-3.12), but not for lifetime psoriasis (OR 1.41, 95% CI 0.93-2.15). There was no evidence for two-way interaction between BMI and 25(OH)D.

CONCLUSIONS

This large population-based study found no significant relationship between 25(OH)D and psoriasis. The analysis may have been underpowered to detect a threshold effect in the lower 25(OH)D spectrum. Interaction analysis indicates that high BMI and vitamin D deficiency combined increase the odds of active psoriasis more than the sum of these factors, with an estimated 92% higher odds for active psoriasis in participants with BMI > 27.5 kg m-2 and 25(OH)D < 25 nmol L-1. Providing advice to prevent vitamin D deficiency may be considered in the follow-up of overweight patients with psoriasis.

Vitamin D level is inversely related to allergen sensitization for risking atopic dermatitis in early childhood

Background

There are few studies concerning the impact of serum vitamin D status on the risk of allergen sensitization and atopic dermatitis (AD) during early childhood.

Method

Children with AD and age-matched healthy controls (HC) were prospectively enrolled at age 0.5, 2, and 4 years. Serum 25-hydroxyvitamin D (25[OH]D) level was measured using Elecsys Vitamin D Total assay. The study utilized the ImmunoCAP assay to analyze specific IgE for food and inhalant allergens, along with total serum IgE levels. It explored the connection between vitamin D levels and allergen sensitization, as well as their influence on AD at different ages.

Results

A total of 222 children including 95 (59 AD and 36 HC), 66 (37 AD and 29 HC), and 61 (32 AD and 29 HC) children were classified at age 0.5, 2, and 4 years, respectively. In children with AD, there was a significantly lower vitamin D level at age 2 and 4, but a significantly higher prevalence of food and mite sensitization at all ages in comparison with HC (P < 0.001). Vitamin D level was found to be inversely related to the prevalence of allergen sensitization at age 4 (P < 0.05). However, vitamin D level appeared to have high importance for allergen sensitization at all ages and AD at age 2 and 4 years.

Conclusion

Vitamin D deficiency is strongly associated with heightened prevalence of allergen sensitization, potentially increasing the susceptibility to AD in early childhood.

Reconstructed Human Skin with Hypodermis Shows Essential Role of Adipose Tissue in Skin Metabolism

BACKGROUND

Dysregulation of skin metabolism is associated with a plethora of diseases such as psoriasis and dermatitis. Until now, reconstructed human skin (RhS) models lack the metabolic potential of native human skin, thereby limiting their relevance to study human healthy and diseased skin. We aimed to determine whether incorporation of an adipocyte-containing hypodermis into RhS improves its metabolic potential and to identify major metabolic pathways up-regulated in adipose-RhS.

METHODS

Primary human keratinocytes, fibroblasts and differentiated adipose-derived stromal cells were co-cultured in a collagen/fibrin scaffold to create an adipose-RhS. The model was extensively characterized structurally in two- and three-dimensions, by cytokine secretion and RNA-sequencing for metabolic enzyme expression.

RESULTS

Adipose-RhS showed increased secretion of adipokines. Both RhS and adipose-RhS expressed 29 of 35 metabolic genes expressed in ex vivo native human skin. Addition of the adipose layer resulted in up-regulation of 286 genes in the dermal-adipose fraction of which 7 were involved in phase I (CYP19A1, CYP4F22, CYP3A5, ALDH3B2, EPHX3) and phase II (SULT2B1, GPX3) metabolism. Vitamin A, D and carotenoid metabolic pathways were enriched. Additionally, pro-inflammatory (IL-1β, IL-18, IL-23, IL-33, IFN-α2, TNF-α) and anti-inflammatory cytokine (IL-10, IL-12p70) secretion was reduced in adipose-RhS.

CONCLUSIONS

Adipose-RhS mimics healthy native human skin more closely than traditional RhS since it has a less inflamed phenotype and a higher metabolic activity, indicating the contribution of adipocytes to tissue homeostasis. Therefore it is better suited to study onset of skin diseases and the effect of xenobiotics.

Serum 25 hydroxyvitamin D in non-scarring alopecia: A systematic review and meta-analysis

INTRODUCTION

Non-scarring alopecia mainly includes androgenetic alopecia (AGA), female pattern hair loss (FPHL), alopecia areata (AA), telogen effluvium (TE), anagen effluvium (AE) and so on. Many studies had investigated the serum 25-hydroxyvitamin D level and vitamin D deficiency of patients with these diseases, but opinions varied, and no conclusion was reached.

METHODS

Relevant articles were retrieved through PubMed, Web of Science, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI) and other databases. Serum 25-hydroxyvitamin D [25(OH) D] levels and vitamin D deficiency were used as our primary outcome. The odds ratio (OR) and the standardized mean difference (SMD) with 95% confidence interval were both examined for vitamin D deficiency and levels.

RESULTS

Our meta-analysis had included a total of 3374 non-scarring alopecia patients and 7296 healthy controls from 23 studies through the inclusion criteria and exclusion criteria. We found non-scarring alopecia had decreased serum 25(OH)D level (WMD -7.29; 95% CI -9.21, -5.38) and increased vitamin D deficiency incidence (OR 3.11 95% CI 2.29, 4.22), compared with healthy controls. This meta-analysis chose to conduct random-effect model and subgroup analysis, because of the high heterogeneity (serum 25(OH)D level: I2 = 95%, vitamin D deficiency: I2 = 0%).

CONCLUSION

Patients with non-scarring alopecia (including AA, FPHL, AGA and TE) have insufficient serum level of 25(OH)D and increased incidence of vitamin D deficiency. Vitamin D supplementation and monitoring for vitamin D deficiency may be helpful in treating non-scarring alopecia.

Efficacy and safety of vitamin D supplementation on psoriasis: A systematic review and meta-analysis

OBJECTIVES

Our aim was to analyze the results of published randomized controlled trials (RCTs) on vitamin D supplementation for psoriasis in order to explore its effectiveness and safety.

PATIENTS AND METHODS

As of July 7 2023, we conducted a systematic literature search in PubMed, Cochrane, Embase, and Web of Science Core Collection databases. The study outcomes included change values in Psoriasis Area and Severity Index (PASI) (at 3 months, 6 months, and end of follow-up)/Dermatology Life Quality Index (DLQI)/Psoriasis disability index (PDI)/C-reactive protein (CRP), and adverse events.

RESULTS

333 patients from 4 studies were evaluated. Pooled analyses showed no significant effect of DLQI/PDI/CRP change value (P > 0.05) or PASI change value (3 months, end of follow-up; P > 0.05). Sensitivity analyses and statistical tests did not support the results of the PASI change values (6 months, P = 0.05). However, the results of subgroup analyses should not be ignored(supplementation with vitamin D2 or Asia would be more effective; P = 0.03). There were no serious adverse effects, and only a few individuals experienced nausea.

CONCLUSIONS

The efficacy and safety of vitamin D supplementation in the treatment of psoriasis remains unremarkable. The search for a new prognostic index that combines clinical and laboratory factors is needed to compensate for the shortcomings of existing measures and provide stronger evidence of validity.

A comprehensive investigation of novel and traditional inflammatory and metabolic markers as predictive indicators in psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory and papulosquamous dermatological disorder. While previous studies have discussed certain inflammatory markers for diagnosing and monitoring psoriasis, there is an absence of comprehensive research encompassing both novel and traditional inflammatory markers, as well as metabolic markers, in relation to psoriasis.

METHODS

A total of 209 individuals participated, including 54 psoriasis patients and 155 controls. Psoriasis Area Severity Index (PASI) was calculated for the patient group. Potential predictive markers for psoriasis were identified: Uric acid/HDL ratio (UHR), D-dimer/albumin ratio (DAR), fibrinogen/albumin ratio (FAR), erythrocyte sedimentation rate, CRP, WBC, HOMA-IR, and vitamin D levels. Differences between groups and correlations with PASI and each other were analyzed using the Mann-Whitney U test and Spearman correlation coefficient.

RESULTS

The results indicate that the patient group exhibited statistically significantly higher levels of UHR, FAR, CRP, WBC, and HOMA-IR. Upon analyzing the correlations between PASI and the identified markers, statistically significant positive correlation with WBC and negative correlation with vitamin D were observed. The correlations of PASI with other markers did not reach statistical significance. It should be underlined that our study was conducted in a predominantly mild-to-moderate patient population.

CONCLUSIONS

The absence of specificity of these markers for psoriasis limits their practical application. However, the development of new objective measures by using them in combination with specific data such as PASI will provide significant benefits in terms of disease diagnosis, follow-up, and treatment.

Efficacy of vitamin D supplementation on the severity of atopic dermatitis in children: A systematic review and meta-analysis

Background: Atopic Dermatitis (AD) is a common dermatosis in children, that includes skin architecture defects, immune dysregulation, and changes of skin flora. Several new drugs have been found to reduce the severity of AD. Vitamin D is one of the new therapies that is still controversial. The purpose of this research is to conclude the efficacy of vitamin D on atopic dermatitis severity in children aged 0-18 years old. Methods: A systematic search was conducted on the PubMed, Cochrane, ProQuest, Google Scholar, Clinical Trial website, and university repositories including studies published from January 2010 through October 2020. We compared populations, intervention, study design, and outcomes. Statistical analysis was done with Review Manager 5.4.1. Results: Eight articles met eligibility and inclusion criteria, four articles provided complete data and were analysed. Not all studies demonstrated the efficacy of vitamin D but a meta-analysis of four studies of vitamin D supplementation vs placebo found a mean difference of -0.93 (95%CI -1.76, to -0.11, p<0.001) of patient outcome, but statistically, there was no difference in cure rate (risk ratio 1.46 (95%CI 0.72, to 2.97, p=0.008) in vitamin D supplementation groups compared to placebo groups. Conclusions: Vitamin D supplementation in paediatric atopic dermatitis patients could offer improvement of disease severity but the recommended dose and duration of administration cannot be concluded yet.

Evaluation of the Impact of Serum Vitamin D Levels on the Scoring Atopic Dermatitis Index in Pediatric Atopic Dermatitis

Atopic dermatitis (AD) is a chronic and recurrent inflammatory skin condition characterized by itching, eczematous plaques, and dry skin. Despite ongoing research, its exact cause remains elusive. In this study, we aimed to explore the factors that influence the severity of AD in children and assess the relationship between serum vitamin D levels and the disease's severity. We enrolled 96 AD patients in our investigation, evaluated their clinical condition using the Scoring Atopic Dermatitis (SCORAD) index, and compared them to a group of 90 healthy controls. Our analysis revealed that serum vitamin D levels and eosinophil counts significantly impacted the SCORAD index (p < 0.001). According to standardized regression coefficients, for each incremental unit in serum vitamin D levels, the SCORAD index exhibited a decrease of 0.449 units. Similarly, a one-unit increase in eosinophil count resulted in a 0.009 unit increase in the SCORAD index. It is worth noting that the influence of serum vitamin D levels on disease severity surpasses that of eosinophil counts and atopic conditions. In our patient cohort, we uncovered a negative correlation (r = -0.419, p < 0.001) between serum vitamin D levels and the SCORAD index. Our findings suggest that low serum vitamin D levels may have a more substantial impact on AD severity than atopic conditions and eosinophilia. Furthermore, we observed a negative association between the severity of AD and serum 25(OH)D3 levels.

Effect of Calcitriol and Vitamin D Receptor Modulator 2 on Recovery of Injured Skeletal Muscle in Wistar Rats

Muscle injuries often result in functional limitations due to insufficient healing. This study assessed the influence of calcitriol and vitamin D Receptor Modulator 2 (VDRM2) on muscle regeneration in male Wistar rats following open blunt muscle injury. The injured left soleus muscle of the rats was treated for the first four days after trauma with local injections of either calcitriol, VDRM2, or a 10% ethanol solution (control). Although muscle strength significantly decreased post-injury, all groups showed gradual improvement but did not achieve full recovery. By the 14th day, calcitriol-treated rats significantly outperformed the control group in the incomplete tetanic force, with VDRM2-treated rats showing muscle strength values that fell between the control and calcitriol groups. Similar trends were observed in complete tetanic contractions and were confirmed histologically via muscle cell width quantification. Additionally, histological analysis showed increased cellular turnover on the fourth postoperative day in the calcitriol group, as indicated by elevated cell proliferation rates and fewer apoptotic cells. VDRM2-treated animals showed only an increased proliferative activity on day 4 after injury. No noticeable differences between the groups for CAE-positive cells or visible muscle tissue area were found. In conclusion, predominantly calcitriol positively influenced post-trauma muscle recovery, where VDRM2 had substantially lower biological activity.

Sex and obesity status modify the association between vitamin D and eczema among adolescents

BACKGROUND

Epidemiologic studies have reported inconsistent associations between vitamin D and eczema. This study sought to assess whether sex and obesity status could modify the association between vitamin D and eczema.

METHODS

A cross-sectional study enrolled 763 adolescents in Kuwait. 25-hydroxyvitamin D (25(OH)D) was measured in venous blood. Current eczema was defined according to clinical history and characteristic morphology and distribution.

RESULTS

In sex-stratified analysis, decreased 25(OH)D levels were associated with increased current eczema prevalence among males (adjusted odds ratio (aOR)tertile 1 vs. tertile 3: 2.14, 95% confidence intervals (CI): 1.07-4.56), but not among females (aORtertile 1 vs. tertile 3: 1.08, 95% CI: 0.71-1.66). Further stratification by obesity status showed that lower 25(OH)D levels were associated with increased current eczema prevalence among overweight/obese males (per 10-unit decrease in 25(OH)D levels: aOR: 1.70, 95% CI: 1.17-2.46). Such an association was weaker and statistically non-significant among overweight/obese females (per 10-unit decrease in 25(OH)D levels: aOR: 1.26, 95% CI: 0.93-1.70).

CONCLUSIONS

Sex and obesity status modified the association between vitamin D levels and eczema, with an inverse association observed among overweight/obese males, but not among overweight/obese females. These results suggest that preventive and clinical management strategies could vary by sex and obesity status.

IMPACT

The current study showed that sex and obesity modify the association between vitamin D and eczema among adolescents. An inverse association between vitamin D and eczema was observed among overweight/obese males, but this association was not as pronounced among overweight/obese females. Vitamin D was not associated with eczema among underweight/normal weight males and females. The identification of effect modification by sex and obesity status add to the current scientific knowledge and further highlight the complexity of the association between vitamin D and eczema. These results may promote a more individualized approach to the future prevention and clinical management of eczema.

A role for vitamin D and the vitamin D receptor in keloid disorder

Keloids are disfiguring fibroproliferative lesions that can occur in susceptible individuals following any skin injury. They are extremely challenging to treat, with relatively low response rates to current therapies and high rates of recurrence after treatment. Although several distinct genetic loci have been associated with keloid formation in different populations, there has been no single causative gene yet identified and the molecular mechanisms guiding keloid development are incompletely understood. Further, although it is well known that keloids are more commonly observed in populations with dark skin pigmentation, the basis for increased keloid risk in skin of colour is not yet known. Because individuals with dark skin pigmentation are at higher risk for vitamin D deficiency, the role of vitamin D in keloid pathology has gained interest in the keloid research community. A limited number of studies have found lower serum vitamin D levels in patients with keloids, and reduced expression of the vitamin D receptor (VDR) in keloid lesions compared with uninjured skin. Vitamin D has documented anti-inflammatory, anti-proliferative and pro-differentiation activities, suggesting it may have a therapeutic role in suppression of keloid fibrosis. Here we review the evidence supporting a role for vitamin D and VDR in keloid pathology.

Psoriasis and Vitamin D: A Systematic Review and Meta-Analysis

Psoriasis is a chronic immune-dysregulated inflammatory disease and hypovitaminosis D is considered a risk factor. We conducted an online database search to review and meta-analyze the relationship between vitamin D, other bone metabolism parameters, and psoriasis. The efficacy of oral vitamin D supplementation in improving Psoriasis Area and Severity Index (PASI) was also evaluated. Non-original articles, case reports, and animal studies were excluded. Bias risk was assessed according to the Cochrane Collaboration's tool and the Newcastle-Ottawa scale in randomized controlled trials (RCTs) and case-control studies, respectively. Unstandardized mean differences were used for data synthesis. Twenty-three studies reported serum 25 hydroxyvitamin D (25(OH)D) levels in 1876 psoriasis patients and 7532 controls. Psoriasis patients had significantly lower 25(OH)D levels than controls (21.0 ± 8.3 vs. 27.3 ± 9.8, p < 0.00001). Conversely, 450 psoriasis patients had lower levels of parathormone than 417 controls (38.7 ± 12.8 vs. 43.7 ± 16.5, p = 0.015). Four RCTs examined the effect of oral vitamin D supplementation on psoriasis for 173 patients and 160 patients were treated with placebo. No significant differences were found in PASI after 3, 6, and 12 months of supplementation. It is shown that 25(OH)D serum levels are significantly lower in psoriasis, but, although the granularity of RCT methodology may have influenced the pooled analysis, vitamin D supplementation did not seem to improve clinical manifestations.

Vitamin D levels in patients with seborrheic dermatitis

OBJECTIVE

Seborrheic dermatitis is a common papulosquamous skin disease with unknown pathogenesis. The aim of our study was to determine the serum level of 25-hydroxy vitamin D in patients with seborrheic dermatitis SD.

METHODS

A total of 53 patients and 60 healthy controls were included in the study. Serum vitamin D, calcium, phosphorus, and parathormone levels were measured in the patient and control groups, and a comparison was made between the two groups regarding these parameters.

RESULTS

Severe vitamin D deficiency was more frequent among patients with seborrheic dermatitisSD compared to controls (52.8 vs. 25.8%, p=0.003). In patients with severe vitamin D deficiency, seborrheic dermatitis SD was detected more frequently at an early age (p=0048) and in women (p=0.015). No correlation was found between the seborrheic dermatitis skin involvement site and vitamin D level.

CONCLUSION

The fact that vitamin D levels decreased in patients with seborrheic dermatitis SD and patients with severe vitamin D deficiency develop seborrheic dermatitis SD earlier suggests that the low levels of vitamin D are related to seborrheic dermatitis.

Association Between VDR and CYP24A1 Polymorphisms, Atopic Dermatitis, and Biochemical Lipid and Vitamin D Profiles in Spanish Population: Case-Control Study

BACKGROUND

Atopic dermatitis (AD) is the most prevalent inflammatory skin disorder, characterized by impaired epidermal barrier function and an altered immune response, both of which are influenced by vitamin D deficiency. Single-nucleotide polymorphisms (SNPs) in VDR and CYP24A1 have been previously associated with AD.

OBJECTIVE

We sought to characterize the associations between the VDR and CYP24A1 polymorphisms and the vitamin D and lipid biochemical profile in children diagnosed with AD.

METHODS

A total of 246 participants (143 patients with AD and 103 healthy controls) were enrolled in this study. Genotyping for polymorphisms in VDR (rs2239185, rs1544410, rs7975232, rs2238136, rs3782905, rs2239179, rs1540339, rs2107301, rs2239182, and rs731236) and CYP24A1 (rs2248359 and rs2296241) was performed by allele-specific polymerase chain reaction using integrated fluidic circuit technology. Serum levels of calcium, phosphorus, and vitamin D were measured, and the biochemical lipid profile was determined.

RESULTS

Among VDR SNPs, rs2239182 exerted a protective effect against the development of AD, whereas rs2238136 was identified as a risk factor for AD. The GCC haplotype (rs2239185-G, rs1540339-C, and rs2238136-C) appeared to protect against the development of AD. rs2239182-CC was associated with higher 25(OH)D concentrations, whereas rs2238136-TT, rs2239185-GA, and rs2248359-TT were present in a large proportion of patients with serum vitamin D deficiency. rs2239185-AA, rs2239182-CC, and rs1540339-CC were associated with higher serum total cholesterol; rs2239182-TT was associated with lower low-density lipoprotein cholesterol; and rs2239182-TC with lower high-density lipoprotein cholesterol. Both CYP24A1 SNPs (rs2296241-AA and rs2248359-TT) were associated with higher high-density lipoprotein cholesterol levels.

CONCLUSIONS

The VDR SNP rs2238136 is a risk factor for AD and other SNPs in VDR and CYP24A1, which may lead to alterations in biochemical parameters that influence the risk of AD. Our findings highlight the complex genetic basis to AD and indicate that interrelationships between different genetic factors can lead to alterations in vitamin D metabolism or lipid profiles, which in turn may influence the development of AD.

The PI3K-Akt-mTOR and Associated Signaling Pathways as Molecular Drivers of Immune-Mediated Inflammatory Skin Diseases: Update on Therapeutic Strategy Using Natural and Synthetic Compounds

The dysregulated phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway has been implicated in various immune-mediated inflammatory and hyperproliferative dermatoses such as acne, atopic dermatitis, alopecia, psoriasis, wounds, and vitiligo, and is associated with poor treatment outcomes. Improved comprehension of the consequences of the dysregulated PI3K/Akt/mTOR pathway in patients with inflammatory dermatoses has resulted in the development of novel therapeutic approaches. Nonetheless, more studies are necessary to validate the regulatory role of this pathway and to create more effective preventive and treatment methods for a wide range of inflammatory skin diseases. Several studies have revealed that certain natural products and synthetic compounds can obstruct the expression/activity of PI3K/Akt/mTOR, underscoring their potential in managing common and persistent skin inflammatory disorders. This review summarizes recent advances in understanding the role of the activated PI3K/Akt/mTOR pathway and associated components in immune-mediated inflammatory dermatoses and discusses the potential of bioactive natural products, synthetic scaffolds, and biologic agents in their prevention and treatment. However, further research is necessary to validate the regulatory role of this pathway and develop more effective therapies for inflammatory skin disorders.

Relationship between genetically proxied vitamin D and psoriasis risk: a Mendelian randomization study

BACKGROUND

Observational research suggests that vitamin D levels affect psoriasis. However, observational studies are prone to potential confounding or reverse causation, which complicates interpreting the data and drawing causal conclusions.

AIM

To apply Mendelian randomization (MR) methods to comprehensively assess a potential association between vitamin D and psoriasis.

METHODS

Genetic variants strongly associated with 25-hydroxyvitamin D (25OHD) in genome-wide association study (GWAS) data from 417 580 and 79 366 individuals from two independent studies served as instrumental variables (used as the discovery and replication datasets, respectively). As the outcome variable, we used GWAS data of psoriasis (13 229 people in the case group, 21 543 in the control group). We used (i) biologically validated genetic instruments, and (ii) polygenic genetic instruments to assess the relationship between genetically proxied vitamin D and psoriasis. We carried out inverse-variance weighted (IVW) MR analyses for the primary analysis. In sensitivity analyses, we used robust MR approaches.

RESULTS

MR analyses of both the discovery and replication datasets did not show an effect of 25OHD on psoriasis. Neither the IVW MR analysis of the biologically validated instruments [discovery dataset: odds ratio (OR) 0.99; 95% confidence interval (CI) 0.88-1.12, P = 0.873; replication dataset: OR 0.98, 95% CI 0.66-1.46, P = 0.930] nor that of the polygenic genetic instruments (discovery dataset: OR 1.00, 95% CI 0.81-1.22, P = 0.973; replication dataset: OR 0.94, 95% CI 0.64-1.38, P = 0.737) revealed an impact of 25OHD on psoriasis.

CONCLUSION

The present MR study did not support the hypothesis that vitamin D levels, measured by 25OHD, affect psoriasis. This study was conducted on Europeans, so the conclusions may not be applicable to all ethnicities.

Effect of Vitamin D Supplementation on Psoriasis Severity in Patients With Lower-Range Serum 25-Hydroxyvitamin D Levels: A Randomized Clinical Trial

Importance

Topical vitamin D analogues are routine treatment for psoriasis, but the effect of oral supplementation has not been established.

Objective

To examine the effect of vitamin D supplementation on psoriasis severity throughout the winter.

Design, Setting, and Participants

This randomized, double-blind placebo-controlled clinical trial with 2 parallel groups was performed through 2 winter seasons (2017 to 2018 and 2018 to 2019). Randomization was computer generated. All participants, health care clinicians, and outcome assessors were masked to group assignment. Each participant was followed for 4 months. The presented analyses were conducted in May 2022. The trial was conducted at the clinical research unit of the University Hospital of North Norway (Tromsø; Norway). Adults from the general population in Tromsø with active plaque psoriasis and 25-hydroxyvitamin D (25[OH]D) levels of less than 24 ng/mL (to convert to nmol/L, multiply by 2.496) were included.

Intervention

Vitamin D (cholecalciferol, 100 000 IU, loading dose, followed by 20 000 IU/week) or placebo for 4 months.

Main outcomes and Measures

Psoriasis Area Severity Index (PASI) (primary outcome), Physician Global Assessment, self-administered PASI, and Dermatology Life Quality Index scores (secondary outcomes).

Results

A total of 122 participants (46 women [37.7%]; mean [SD] age, 53.6 [10.0] years; mean [SD] PASI score, 3.1 [2.0]; mean [SD] serum 25(OH)D, 14.9 [3.9] ng/mL) were included. Of these, 60 (49.2%) were randomized to the vitamin D group and 62 (50.8%) to the placebo group. A total of 120 participants (59 vitamin D [49.2%]/61 placebo [51.8%]) completed the study. By completion, mean (SD) 25(OH)D levels were 29.7 (5.2) ng/mL (vitamin D) and 12.0 (3.8) ng/mL (placebo). There was no significant difference in change in PASI score between the groups (adjusted difference, 0.11; 95% CI, -0.23 to 0.45). There was no significant difference in change in Physician Global Assessment score (adjusted odds ratio, 0.66; 95% CI, 0.27-1.63), self-administered PASI (adjusted difference, -0.60; 95% CI, -1.76 to 0.55) or Dermatology Life Quality Index (adjusted difference, -0.86; 95% CI, -1.9 to 0.19) between the groups. No adverse effects of the intervention were registered.

Conclusion and Relevance

The results of this randomized clinical trial showed that vitamin D supplementation did not affect psoriasis severity. Low baseline severity scores may explain the lack of measurable effect. Levels of 25(OH)D in the intervention group increased to a less-than-expected degree based on previous experimental data from the same source population, and this may have affected the results.

Trial Registration

ClinicalTrials.gov Identifier: NCT03334136.

Are There Ethnic Differences in Hand Eczema? A Review

Hand eczema is a common disease with economic and social ramifications. This study undertakes a review of certain existing literature to provide insight into contributory factors which may result in the varying prevalence and severity of hand eczema among different ethnic groups, particularly to identify modifiable risk factors, as well as to ascertain knowledge gaps for future research direction. The existing literature suggests that factors including (a) genes, (b) differing skin physiology, (c) cultural practices, (d) dietary habits and associated food preparation, (e) climate, (f) predominant occupations, (g) socioeconomic factors, and (h) dissimilar laws and regulations may account for the disparity in the risk of hand eczema among different ethnicities. Given that endogenous factors cannot be avoided, but certain exogenous aspects can be modified, especially as the environment plays an important role in hand eczema flares, it is helpful from a practical perspective to focus on addressing the modifiable risk factors. These factors pertain to unique cultural practices, customs, and food preparation methods. Healthcare professionals should be well-acquainted with such factors to tailor the treatment approach for patients of different ethnicities accordingly because, with globalization, physicians face increasingly diverse patient populations such that cultural customs no longer remain limited to particular geographic regions.

Comparing Vitamin D Level Between Patients with Psoriasis and Healthy Individuals: A Systematic Review and Meta-Analysis

BACKGROUND

Psoriasis is nowadays regarded as a systemic inflammatory disorder. Among the topicals, vitamin D derivates are often applied on the skin for their anti-inflammatory and immune-modulatory properties. Vitamin D serum levels in psoriasis (PsO) patients are still debated and an eventual depletion may offer the rational to integrate anti-psoriatic therapies with oral vitamin D. Then, we aimed to perform a systematic review and meta-analysis on the current evidence towards serum vitamin D level in PsO.

METHODS

We searched in PubMed, Scopus, Web of Sciences, ScienceDirect and Science Information Database (SID) using the terms "Vitamin D" and "Psoriasis" including manuscripts in English, Italian and Persian. Duplications were excluded using EndNote software and records were screened by title, abstract and full-text. Quality assessment of studies was assessed using Newcastle Ottawa Checklist (NOS). Psoriasis odds ratio (OR) and mean serum vitamin D levels were calculated and displayed in Forest-plots. Heterogeneity indexes were evaluated using I2 and Q. Sensitivity analysis and publication biases were also considered.

RESULTS

From 3006 records extracted, after removing duplicates and analyzing full texts we finally included 19 manuscripts involving a total of 1387 PsO cases and 6939 controls. PsO patients exhibited a substantial odds ratio (3.07, 95% CI: 1.56-6.04) for lower serum vitamin D levels compared to the control group. Standardized Mean Difference (SMD) of vitamin D in PsO versus controls was -0.92 (-1.33 to -0.51).

CONCLUSION

Psoriatic patients displayed higher risk to have a vitamin D deficiency. Interventional studies to verify the preventive value are mandatory.

TRPV1: A promising therapeutic target for skin aging and inflammatory skin diseases

TRPV1 is a non-selective channel receptor widely expressed in skin tissues, including keratinocytes, peripheral sensory nerve fibers and immune cells. It is activated by a variety of exogenous or endogenous inflammatory mediators, triggering neuropeptide release and neurogenic inflammatory response. Previous studies have shown that TRPV1 is closely related to the occurrence and/or development of skin aging and various chronic inflammatory skin diseases, such as psoriasis, atopic dermatitis, rosacea, herpes zoster, allergic contact dermatitis and prurigo nodularis. This review summarizes the structure of the TRPV1 channel and discusses the expression of TRPV1 in the skin as well as its role of TRPV1 in skin aging and inflammatory skin diseases.

Bone Metabolism in Patients with Hidradenitis Suppurativa: A Case-control Study

Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the hair follicles. The aim of this case-control study was to assess whether HS is associated with disturbances in trabecular bone score, bone mineral density, bone remodelling markers, and calciotropic hormones. A total of 81 patients and 79 controls of similar age and sex were included. Demographic, anthropometric, laboratory data, trabecular bone score, bone mineral density, serum 25-hydroxyvitamin D (25OHD), serum amino-terminal pro-peptide of type 1 collagen (PINP), and C-terminal telopeptide of type 1 collagen (CTX) concentrations were assessed in both groups. Patients with HS had lower serum 25OHD levels than controls, and approximately 62% of them had vitamin D deficiency. Serum PINP was increased and CTX was decreased in patients with HS. Fully adjusted trabecular bone score values were lower in patients with HS compared with controls. Adjusted lumbar bone mineral density was similar in HS and controls, whilst total hip bone mineral density was lower in patients with HS. There were no statistical differences regarding disease severity in terms of 25OHD, serum turnover markers, bone mineral density, or trabecular bone score values. This study shows that patients with HS have lower trabecular bone score and total hip bone mineral density values than population-based controls. In addition, the prevalence of vitamin D deficiency is high in subjects with HS.

Risk factors for food sensitization in children with atopic dermatitis: a single-center cross-sectional study

OBJECTIVES

To study the risk factors for food sensitization and the influence of food sensitization on quality of life and clinical signs in children with atopic dermatitis (AD).

METHODS

A retrospective analysis was performed on the medical data of 241 children with AD, including demographic features, age of onset, severity of AD, quality of life, physical examination results, skin prick test (SPT) results, serum total IgE levels, and eosinophil count. According to the results of SPT, the children were divided into a food sensitization group (n=127) and a non-food sensitization group (n=114). The multivariate logistic regression analysis was used to identify the risk factors for food sensitization in children with AD.

RESULTS

The prevalence rate of food sensitization was 52.7% (127/241) in the children with AD. The multivariate logistic regression analysis showed that birth in autumn or winter, age of onset of AD<12 months, severe AD, and total IgE>150 IU/mL were risk factors for food sensitization (P<0.05). Compared with the non-food sensitization group, the food sensitization group had a significantly poorer quality of life (P=0.008) and significantly higher prevalence rates of non-specific hand/foot dermatitis and palmar hyperlinearity (P<0.05). Compared with the single food sensitization group, the multiple food sensitization group had more severe AD and a significantly higher proportion of children with exclusive breastfeeding or total IgE>150 IU/mL (P<0.05).

CONCLUSIONS

The AD children born in autumn or winter, or those with early onset (<12 months), severe AD or total IgE>150 IU/mL have a higher risk of food sensitization. The AD children with food sensitization have a poorer quality of life and are more likely to develop non-specific hand/foot dermatitis and palmar hyperlinearity.

Vitamin D as a drug: new therapeutic approaches

Vitamin D is one of the essential vitamins and has recently been demonstrated to be much more important for the appropriate functioning of the human body and well-being than initially believed. Although vitamin D is mainly known for its link with bone fractures and bone diseases, recent studies revealed that vitamin D and its analogues have revealed many pharmacological actions covering the regulation of cell growth, inhibition of inflammation, and improvement of neuromuscular function and immune function. Moreover, vitamin D and its analogues are reported to have role in different types of cancers, skin diseases, diabetes mellitus and infections caused by different bacterial and viral pathogens including SARS-CoV-2. The goal of this study is to evaluate the scientific literature on therapeutic uses of vitamin D and its analogues against different diseases and health condition. Special attention has been given to COVID-19 infection, cancer, skin diseases, and diabetes. The molecular mechanisms involved are also explored.

Vitamin D, cytokine profiles, and disease severity in infants with atopic dermatitis: a single centre, cross-sectional study

Introduction

Atopic dermatitis (AD) is an immune-mediated inflammatory skin disease and generally develops in infancy. Studies evaluating the role of vitamin D in immune mechanims in AD showed varying results.

Aim

To assess the association between serum vitamin D, cytokine profiles, and disease severity in infants with AD.

Material and methods

A cross-sectional study was conducted on infants aged 0–12 months with AD in the Paediatric Allergy and Immunology Department, Saiful Anwar Hospital, Indonesia. The disease severity was assessed by the Scoring of Atopic Dermatitis (SCORAD) index. Blood was drawn to evaluate the total eosinophil count (TEC), total immunoglobulin E (tIgE), 25-hydroxyvitamin D (25(OH)D), interleukin-4 (IL-4), IL-17A, and IL-22 levels.

Results

This study enrolled 36 infants including 19 with mild AD and 17 with moderate AD. Vitamin D deficiency and insufficiency were found in 18 (50%) and 9 (25%) subjects, respectively. The mean 25(OH)D level was lower and the mean IL-4, IL-17A, and IL-22 levels were higher in the moderate AD group than in the mild AD group (p < 0.05). A lower level of 25(OH)D was associated with a higher level of IL-17A (r = –0.315, p = 0.041). The SCORAD index was negatively correlated with 25(OH)D (r = –0.714, p < 0.001) and positively correlated with IL-17A (r = 0.522, p = 0.001) and IL-22 (r = 0.612, p < 0.001) but not IL-4 (r = 0.325, p = 0.053).

Conclusions

There was a high prevalence of vitamin D deficiency and insufficiency in infants with AD, and a low vitamin D level was correlated with the severity of AD, dependently on IL-17A.

Clinical Value of Vitamin D, Trace Elements, Glucose, and Lipid Metabolism in Diagnosis and Severity Evaluation of Psoriasis

Objective

The levels of vitamin D, trace elements, and glucose and lipid metabolism in psoriasis were evaluated, and their value in disease diagnosis and severity evaluation was explored.

Methods

In this study, the serum trace elements, blood glucose, and blood lipid indexes of 360 patients with psoriasis and 500 healthy subjects were compared and analyzed.

Results

The results of 25-(OH) D3, Cu/Zn, and HDL-C in patients with psoriasis were significantly different from those in the control group. With the aggravation of the disease, Psoriasis Area and Severity Index (PASI) was positively correlated with 25-(OH) D3 and HDL-C and negatively correlated with Cu/Zn. The AUC of the three indexes for the diagnosis of psoriasis was 0.899, 0.675, and 0.848, respectively.

Conclusion

There are metabolic abnormalities of 25-(OH) D3, Cu/Zn, and HDL-C in patients with psoriasis, and paying attention to these indicators is conducive to the diagnosis of disease.

Vitamin D supplementation in patients with atopic dermatitis, chronic urticaria and contact irritant and allergic dermatitis - possible improvement without risk

Abstract.

Effect of Vitamin D Serum Levels and Supplementation on Atopic Dermatitis: A Systematic Review and Meta-analysis

BACKGROUND

Previous studies have shown that serum 25-hydroxyvitamin D (25(OH)D) may be associated with atopic dermatitis (AD), and that vitamin D (VD) supplementation may decrease AD severity.

OBJECTIVE

The aim of this study was to investigate the association between serum 25(OH)D level and AD, and the effect of VD supplementation on AD severity, while providing stratified analyses based on latitude and region.

METHODS

A systematic review was performed on all published studies in MEDLINE, Embase, and Cochrane Library databases that analyzed effects of serum 25(OH)D and VD supplementation on AD.

RESULTS

This systematic review and meta-analysis includes 20 studies with 1882 cases of AD. We found significantly lower 25(OH)D levels in AD patients compared with healthy controls (HC) (p < 0.001), significantly lower 25(OH)D levels in severe AD compared with both mild and moderate AD (p < 0.001), and VD supplementation improved AD symptoms (p < 0.001).

LIMITATIONS

Factors like seasonal and environmental changes, sunlight exposure, and cultural practices may confound the relationship between serum 25(OH)D and AD severity. There are limited randomized controlled trials that assess this association.

CONCLUSION

Overall, lower serum 25(OH)D is associated with more severe AD, and VD supplementation may help lower AD severity. Further research is needed to confirm the presence and direction of causality of the relationship between VD and AD pathogenesis.

Pre- and Postnatal Vitamin D Status and Allergy Outcomes in Early Childhood

The dramatic increase in the prevalence of allergic disease in recent decades reflects environmental and behavioural changes that have altered patterns of early immune development. The very early onset of allergic diseases points to the specific vulnerability of the developing immune system to environmental changes and the development of primary intervention strategies is crucial to address this unparalleled burden. Vitamin D is known to have immunomodulatory functions. While allergic disease is multifactorial, associations with reduced sunlight exposure have led to the hypothesis that suboptimal vitamin D levels during critical early periods may be one possible explanation. Interventions to improve vitamin D status, especially in early life, may be the key to allergic disease prevention.

Maternal Vitamin D Status Correlates to Leukocyte Antigenic Responses in Breastfeeding Infants

It is unknown if vitamin D (vitD) sufficiency in breastfeeding mothers can lead to physiological outcomes for their children that are discernible from infant vitD sufficiency per se. In a 3-month, randomized vitD supplementation study of mothers and their exclusively breastfeeding infants, the effects of maternal vitD sufficiency were determined on infant plasma concentrations of 25-hydroxyvitamin D (i.e., vitD status) and 11 cytokines. An inverse correlation was seen between maternal vitD status and infant plasma TNF concentration (r = −0.27; p < 0.05). Infant whole blood was also subjected to in vitro antigenic stimulation. TNF, IFNγ, IL-4, IL-13, and TGFβ1 responses by infant leukocytes were significantly higher if mothers were vitD sufficient but were not as closely correlated to infants’ own vitD status. Conversely, IL-10 and IL-12 responses after antigenic challenge were more correlated to infant vitD status. These data are consistent with vitD-mediated changes in breast milk composition providing immunological signaling to breastfeeding infants and indicate differential physiological effects of direct-infant versus maternal vitD supplementation. Thus, consistent with many previous studies that focused on the importance of vitD sufficiency during pregnancy, maintenance of maternal sufficiency likely continues to affect the health of breastfed infants.

Efficacy of vitamin D supplementation on the severity of atopic dermatitis in children: A systematic review and meta-analysis

Background: Atopic Dermatitis (AD) is a common dermatosis in children, that includes skin architecture defects, immune dysregulation, and changes of skin flora. Several new drugs have been found to reduce the severity of AD. Vitamin D is one of the new therapies that is still controversial. The purpose of this research is to conclude the efficacy of vitamin D on atopic dermatitis severity in children aged 0-18 years old. Methods: A systematic search was conducted on the PubMed, Cochrane, ProQuest, Google Scholar, Clinical Trial website, and university repositories including studies published from January 2010 through October 2020. We compared populations, intervention, study design, and outcomes. Statistical analysis was done with Review Manager 5.4.1. Results: Eight articles met eligibility and inclusion criteria, four articles provided complete data and were analysed. Not all studies demonstrated the efficacy of vitamin D but a meta-analysis of four studies of vitamin D supplementation vs placebo found a mean difference of -0.93 (95%CI -1.76, to -0.11, p<0.001) of patient outcome, but statistically, there was no difference in cure rate (risk ratio 1.46 (95%CI 0.72, to 2.97, p=0.008) in vitamin D supplementation groups compared to placebo groups. Conclusions: Vitamin D supplementation in paediatric atopic dermatitis patients could offer improvement of disease severity but the recommended dose and duration of administration cannot be concluded yet.

Deficiency of vitamin D receptor in keratinocytes augments dermal fibrosis and inflammation in a mouse model of HOCl-induced scleroderma

Scleroderma, characterized by extensive fibrosis and vascular alterations, involves excessive fibroblast activation, uncontrolled inflammation, and abnormal collagen deposition. Previous studies showed that administrations of either 1,25(OH)2D3 or vitamin D analog effectively decreased or reversed skin fibrosis by regulating the extracellular matrix homeostasis. The actions of 1,25(OH)2D3 are mediated by the vitamin D receptor (VDR), a transcription regulator crucial for skin homeostasis. Although evidence suggests that keratinocyte-fibroblast interaction influences the development of scleroderma, the role of keratinocytes in scleroderma remains unknown. Here, we demonstrated that the ablation of VDR in keratinocytes greatly exacerbated dermal fibrosis in HOCl-induced scleroderma in mice. The deficiency of VDR in the epidermis marked increased dermal thickness, inflammatory cell infiltration, and severe collagen deposition in comparison to the control group in HOCl-treated skin. Moreover, significant elevations in expression levels of mRNA for collagen overproduction (Col1A1, Col1A2, Col3A1, α-SMA, MMP9, TGF-β1) and proinflammatory cytokines (IL-1β, IL-6, CXCL1, CXCL2) were observed in VDR conditional KO versus control mice following HOCl treatment. Collectively, these results suggest that VDR in keratinocytes plays a pivotal role in scleroderma progression, and the interplay between keratinocytes and fibroblasts deserves more attention regarding the exploration of the pathogenesis and treatment for scleroderma.

IL-22 Downregulates Peptidylarginine Deiminase-1 in Human Keratinocytes: Adding Another Piece to the IL-22 Puzzle in Epidermal Barrier Formation

Increased presence of IL-22+ cells in the skin is a characteristic finding in skin barrier defects, such as psoriasis and atopic dermatitis. However, mechanistic insight into effects of IL-22 on epidermal functioning is yet to be elucidated. One crucial step during epidermal differentiation is deimination or citrullination. Here, we show reduced levels of peptidylarginine deiminase 1, an enzyme that converts peptidylarginine into citrulline in lesional psoriatic skin. IL-22 signaling through the IL-22 receptor complex was found to suppress expression of peptidylarginine deiminase 1 in epidermal keratinocytes. Subsequently, total peptidylarginine deiminase activity and extent of protein deimination in keratinocytes treated with IL-22 were reduced together with a significant decrease in deimination of keratin 1 and FLG, both important for epidermal differentiation. Vitamin D and acitretin partly restored the peptidylarginine deiminase 1 defect caused by IL-22. Collectively, we show that IL-22 downregulates deimination, thus identifying a potential target for treatment of skin barrier defects.

The Brain-Skin Axis in Psoriasis-Psychological, Psychiatric, Hormonal, and Dermatological Aspects

Psoriasis is a chronic inflammatory skin disease with systemic manifestation, in which psychological factors play an important role. The etiology of psoriasis is complex and multifactorial, including genetic background and environmental factors such as emotional or physical stress. Psychological stress may also play a role in exacerbation of psoriasis, by dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis, sympathetic–adrenal–medullary axis, peripheral nervous system, and immune system. Skin cells also express various neuropeptides and hormones in response to stress, including the fully functional analog of the HPA axis. The deterioration of psoriatic lesions is accompanied by increased production of inflammatory mediators, which could contribute to the imbalance of neurotransmitters and the development of symptoms of depression and anxiety. Therefore, deregulation of the crosstalk between endocrine, paracrine, and autocrine stress signaling pathways contributes to clinical manifestations of psoriasis, which requires multidisciplinary approaches.

Itch: Epidemiology, clinical presentation, and diagnostic workup

Itch, or pruritus, is the uncomfortable sensation underlying the desire to scratch. Itch is a very common complaint in the general population that can result from dermatologic, systemic (eg, renal, hepatobiliary, endocrine), paraneoplastic, neuropathic, and psychogenic etiologies. Chronic itch is associated with significant sleep disturbances and profoundly reduces overall quality of life. Certain populations, including elderly and African Americans, are at increased risk of experiencing heightened burden of itch. Because of the variable clinical presentation and wide-ranging etiologies, itch presents a challenge for clinicians. The initial evaluation should include a complete blood count, with differential, hepatic, renal, and thyroid function testing along with diabetes screening. Further testing should be guided by history and physical examination findings. There should be a heightened concern for underlying malignancy in individuals older than 60 years of age who have a history of liver disease and diffuse itch less than 12 months of duration. For individuals with chronic pruritus of unknown origin, increased blood eosinophils may serve as a biomarker of T helper cell type 2 polarization and response to immunomodulator therapies. In this first part of a 2-part continuing medical education series, we describe the broader epidemiology and specific conditions associated with itch and the clinical presentation and diagnostic workup for patients with itch.