Lower vitamin D status is closely correlated with eczema of the head and neck

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.

Atopic dermatitis does not increase the risk of inflammatory bowel disease: A nationwide cohort study

Coexistence of inflammatory bowel disease (IBD) in atopic dermatitis (AD) patients has been reported. The long-term risk of IBD in AD patients remains unclear. Our aim for the study is to examine the long-term risk of IBD in AD patients. This is a nationwide cohort study. From the National Health Insurance Research Database of Taiwan (1997-2013), a total of 36 400 AD patients were identified and matched with 364 000 reference subjects without AD by age, sex and number of hospital visits. Demographic characteristics and comorbidities were compared. Cox proportional hazards regression analysis was conducted to examine the risk of IBD. The 16-year cumulative incidences of IBD were 0.047% (95% confidence interval [CI], 0.040-0.054) and 0.047% (95% CI, 0.025-0.096) in non-AD and AD cohorts, respectively (P = 0.973). There were 17 cases of IBD (0.05%), including 10 ulcerative colitis and seven Crohn's disease, among AD patients compared with 169 IBD cases (0.05%) among controls (P > 0.999). Infections (adjusted hazard ratio [HR], 2.71; 95% CI, 1.96-3.95; P < 0.001) and age (adjusted HR, 1.03; 95% CI, 1.02-1.03; P < 0.001) were independently associated with IBD, after adjusting for major comorbidities and conducting multivariate analyses. AD was not associated with IBD development. In conclusion, AD is not independently associated with IBD development.

Vitamin D Deficiency and Effects of Vitamin D Supplementation on Disease Severity in Patients with Atopic Dermatitis: A Systematic Review and Meta-Analysis in Adults and Children

Research has investigated 25-hydroxyvitamin D (25(OH)D) levels in the Atopic Dermatitis (AD) population, as well as changes in AD severity after vitamin D (VitD) supplementation. We performed an up-to-date systematic review and meta-analysis of these findings. Electronic searches of MEDLINE, EMBASE and COCHRANE up to February 2018 were performed. Observational studies comparing 25(OH)D between AD patients and controls, as well as trials documenting baseline serum 25(OH)D levels and clinical severity by either SCORAD/EASI scores, were included. Of the 1085 articles retrieved, sixteen were included. A meta-analysis of eleven studies of AD patients vs. healthy controls (HC) found a mean difference of −14 nmol/L (95% CI −25 to −2) for all studies and −16 nmol/L (95% CI −31 to −1) for the paediatric studies alone. A meta-analysis of three VitD supplementation trials found lower SCORAD by −11 points (95% CI −13 to −9, p < 0.00001). This surpasses the Minimal Clinical Important Difference for AD of 9.0 points (by 22%). There were greater improvements in trials lasting three months and the mean weighted dose of all trials was 1500–1600 IU/daily. Overall, the AD population, especially the paediatric subset, may be at high-risk for lower serum 25(OH)D. Supplementation with around 1600 IU/daily results in a clinically meaningful AD severity reduction.

Clinical Diversity of Atopic Dermatitis: A Review of 5,000 Patients at a Single Institute

PURPOSE

Atopic dermatitis (AD) is a chronic eczematous dermatitis that has a high prevalence and diverse clinical features. Although several hypotheses about its multifactorial pathogenesis have been suggested, the cause is not yet fully understood. A better understanding of the clinical features may helpful inelucidating the pathogenesis of AD.

METHODS

This retrospective study analyzed the questionnaires, medical charts, and laboratory examination results of 5,000 patients diagnosed with AD at a single tertiary hospital in Korea.

RESULTS

The demographics, allergic comorbidities, family history, severity, and treatment experiences of the patients were analyzed. Most of the patients were adults, 76.3% of whom were classified as havingan extrinsic type of AD. The mean eczema area and severity index (EASI) score was found to be 13.68, and adult patients were found to have higher severity than the other age groups. The anatomical involvements were different among the age groups, with more involvements of the head and neck in adults. The patients reported seasonal changes and stress as the factors that aggravated their symptoms the most. Topical steroids and oral cyclosporine were the most used medications at our clinic, whereas 10.1% of the patients underwent allergen-specific immunotherapy.

CONCLUSIONS

This analysis of 5,000 patients would lead to a better understanding of various subtypes and diverse clinical features of AD in Koreans. Distinct characteristics were observed among different age groups; thus, treatment strategies may need to be differentiated accordingly.

Vitamin D Status and Efficacy of Vitamin D Supplementation in Atopic Dermatitis: A Systematic Review and Meta-Analysis

Recent literature has highlighted the possible role of vitamin D in atopic dermatitis (AD), and that vitamin D supplementation might help to treat AD. This study determined the relationship between vitamin D level and AD, and assessed the efficacy of vitamin D supplementation. We searched the MEDLINE, EMBASE, and Cochrane databases up to May 2015. Observational studies and randomized controlled trials were included based on the available data on the serum 25-hydroxyvitamin D (25(OH)D) level and quantified data available for severity assessed using the Scoring Atopic Dermatitis (SCORAD) index or Eczema Area and Severity Index (EASI) score. Compared with healthy controls, the serum 25(OH)D level was lower in the AD patients of all ages (standardized mean difference = −2.03 ng/mL; 95% confidence interval (CI) = −2.52 to −0.78), and predominantly in the pediatric AD patients (standardized mean difference = −3.03 ng/mL; 95% CI = −4.76 to −1.29). In addition, the SCORAD index and EASI score decreased after vitamin D supplementation (standardized mean difference = −5.85; 95% CI = −7.66 to −4.05). This meta-analysis showed that serum vitamin D level was lower in the AD patients and vitamin D supplementation could be a new therapeutic option for AD.

Association between vitamin D levels and allergy-related outcomes vary by race and other factors

BACKGROUND

Allergy-related studies that include biological measurements of vitamin D preceding well-measured outcomes are needed.

OBJECTIVE

We sought to examine the associations between early-life vitamin D levels and the development of allergy-related outcomes in the racially diverse Wayne County Health, Environment, Allergy, and Asthma Longitudinal Study birth cohort.

METHODS

25-Hydroxyvitamin D (25[OH]D) levels were measured in stored blood samples from pregnancy, cord blood, and age 2 years. Logistic regression models were used to calculate odds ratios (ORs) with 95% CIs for a 5 ng/mL increase in 25(OH)D levels for the following outcomes at age 2 years: eczema, skin prick tests (SPTs), increased allergen-specific IgE level (≥ 0.35 IU/mL), and doctor's diagnosis of asthma (3-6 years).

RESULTS

Prenatal 25(OH)D levels were inversely associated with eczema (OR, 0.85; 95% CI, 0.75-0.96). The association was stronger in white children (white children: OR, 0.79; 95% CI, 0.57-1.09; black children: OR, 0.96; 95% CI, 0.82-1.12), although this was not statistically significant. Cord blood 25(OH)D levels were inversely associated with having 1 or more positive SPT responses and aeroallergen sensitization. Both associations were statistically significant in white children (positive SPT response: OR, 0.50; 95% CI, 0.32-0.80; ≥ 1 aeroallergen sensitization: OR, 0.50; 95% CI, 0.28-0.92) in contrast with black children (positive SPT response: OR, 0.88; 95% CI, 0.68-1.14; ≥ 1 aeroallergen sensitization: OR, 0.85; 95% CI, 0.65-1.11). 25(OH)D levels measured concurrently with outcome assessment were inversely associated with aeroallergen sensitization (OR, 0.79; 95% CI, 0.66-0.96) only among black children (white children: OR, 1.21; 95% CI, 0.87-1.69).

CONCLUSIONS

Prenatal and cord blood 25(OH)D levels were associated with some allergy-related outcomes, with a general pattern indicating that children with higher 25(OH)D levels tend to have fewer allergy-related outcomes.

Vitamins A and D have antagonistic effects on expression of effector cytokines and gut-homing integrin in human innate lymphoid cells

BACKGROUND

Retinoic acid (RA), the main biologically active metabolite of vitamin A, is known to promote gut homing of lymphocytes, as well as various regulatory and effector immune responses. In contrast, the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D3), is predominantly immunosuppressive. Little is known about the direct effects of these vitamins on the recently identified innate lymphoid cells (ILCs).

OBJECTIVE

We sought to characterize the effects of RA and 1,25D3 on human ILCs.

METHODS

Peripheral blood mononuclear cells were isolated from 27 non-selected blood donor buffy coats, and ILCs were sorted by FACS. ILC1, ILC2, and ILC3 cells were cultured for 5 days with RA, 1,25D3, and various cytokines known to activate ILCs (IL-2, IL-7, IL-12, thymic stromal lymphopoietin (TSLP), IL-25, and IL-33). Cytokines produced by ILCs were measured in culture supernatants, and surface receptor expression was analysed by flow cytometry.

RESULTS

Retinoic acid acted synergistically with IL-2 and other activating cytokines to induce expression of the gut-homing integrin α4β7 in ILCs, as well as production of IL-5 and IL-13 in ILC2 cells, and IFN-γ in ILC1 and ILC3 cells. Expression of integrin α4β7 and cytokine production in ILCs stimulated with RA + IL-2 was increased at least fourfold as compared to ILCs cultured with RA or IL-2 alone. In contrast, RA completely inhibited the IL-2-induced expression of cutaneous lymphocyte antigen (CLA) in ILCs. Moreover, addition of 1,25D3 to ILCs cultured with RA + IL-2 inhibited cytokine production and expression of integrin α4β7 by at least 30%.

CONCLUSIONS

Retinoic acid and 1,25D3 have antagonistic effects on the expression of effector cytokines and gut-homing integrin by human ILCs. The balance between these vitamins may be an important factor in the functioning of ILCs and the diseases in which ILCs are implicated, such as allergic inflammation.

Vitamin D and the Development of Atopic Eczema

A “vitamin D hypothesis” has been proposed to explain the increased prevalence of eczema in regions with higher latitude. This review focuses on the current available evidence with regard to the possible effect of vitamin D on the development of atopic eczema. Observational studies have indicated a link between vitamin D status and eczema outcomes, including lower serum vitamin D levels associated with increased incidence and severity of eczema symptoms. Vitamin D is known to have a regulatory influence on both the immune system and skin barrier function, both critical in the pathogenesis of eczema. However heterogeneous results have been found in studies to date investigating the effect of vitamin D status during pregnancy and infancy on the prevention of eczema outcomes. Well-designed, adequately powered, randomised controlled trials are needed. The study design of any new intervention trials should measure vitamin D levels at multiple time points during the intervention, ultraviolet (UV) radiation exposure via the use of individual UV dosimeters, and investigate the role of individual genetic polymorphisms. In conclusion, the current available evidence does not allow firm conclusions to be made on whether vitamin D status affects the development of atopic eczema.