"Inflammatory skin march" in atopic dermatitis and psoriasis

Interplay between diabetes mellitus and atopic dermatitis

Inflammatory dermatoses such as atopic dermatitis (AD) have long been linked to the pathogenesis of diabetes mellitus. Indeed, numerous studies show an increased risk of diabetes mellitus in individuals with AD although lower prevalence of diabetes mellitus is also observed in few studies. Though the underlying mechanisms accounting for the reciprocal influence between these two conditions are still unclear, the complex interplay between diabetes mellitus and AD is attributable, in part, to genetic and environmental factors, cytokines, epidermal dysfunction, as well as drugs used for the treatment of AD. Proper management of one condition can mitigate the other condition. In this review, we summarize the evidence of the interaction between diabetes mellitus and AD, and discuss the possible underlying mechanisms by which these two conditions influence each other.

Effectiveness, safety and impact of guselkumab on sexuality and perceived stigmatization in patients with psoriasis in routine clinical practice: Week 28 results from the prospective German multicentre G-EPOSS study

BACKGROUND

G-EPOSS is a prospective, non-interventional, German multicentre study of patients with moderate-to-severe plaque psoriasis receiving guselkumab, a therapeutic monoclonal antibody targeting interleukin-23, in a real-world setting.

OBJECTIVES

The objective of the study was to evaluate the effectiveness and safety of guselkumab, including its impact on skin, health-related quality of life (HRQoL), sexuality, and perceived stigmatization.

METHODS

Patients (≥18 years old) received guselkumab per routine clinical practice. The primary endpoint was the proportion of patients achieving absolute Psoriasis Area and Severity Index (PASI) ≤ 3 at Week (W)28. Secondary endpoint assessments over 28 weeks included the Nail Psoriasis Severity Index (NAPSI), anogenital Physician's Global Assessment (aPGA), and Dermatology Life Quality Index (DLQI). Sexuality and perceived stigmatization were assessed by patients using the Relationship and Sexuality Scale (RSS) and Perceived Stigmatization Questionnaire (PSQ), respectively.

RESULTS

Overall, 293 patients were included in the evaluable set population. Mean age and disease duration were 45.6 and 17.6 years, respectively. At baseline, mean PASI, aPGA and DLQI scores were 15.3, 2.7 and 11.3, respectively. In total, 25.9% of patients had received a prior biologic. Overall, 83.0% of patients achieved PASI ≤ 3, and 56.2%/35.1% achieved PASI ≤ 1/PASI = 0, respectively, at W28. Among those with NAPSI ≥ 1 and aPGA ≥ 1 at baseline, NAPSI = 0 and aPGA = 0 were achieved by 39.2% and 61.1% of patients, respectively, and 61.4% of patients achieved DLQI 0-1 at W28. Improvements were observed over 28 weeks across individual items of the DLQI, RSS and PSQ, indicating improved HRQoL and sex life, and decreased perceived stigmatization. Based on DLQI Question (Q)9, 53.6% of patients experienced sexual difficulties at baseline, which decreased to 12.1% at W28. DLQI Q9 responses were consistent with RSS item responses, highlighting DLQI Q9 as a sentinel for sexual impairment.

CONCLUSIONS

Guselkumab improved overall skin symptoms and HRQoL in patients with psoriasis and decreased sexual impairment and perceived stigmatization. No new safety signals were observed.

STUDY CODE

CNTO1959PSO4008.

An OX-Tra'Ordinary Tale: The Role of OX40 and OX40L in Atopic Dermatitis

The transmembrane glycoprotein OX40 receptor (OX40) and its ligand, OX40L, are instrumental modulators of the adaptive immune response in humans. OX40 functions as a costimulatory molecule that promotes T cell activation, differentiation, and survival through ligation with OX40L. T cells play an integral role in the pathogenesis of several inflammatory skin conditions, including atopic dermatitis (AD). In particular, T helper 2 (TH2) cells strongly contribute to AD pathogenesis via the production of cytokines associated with type 2 inflammation (e.g., IL-4, IL-5, IL-13, and IL-31) that lead to skin barrier dysfunction and pruritus. The OX40-OX40L interaction also promotes the activation and proliferation of other T helper cell populations (e.g., TH1, TH22, and TH17), and AD patients have demonstrated higher levels of OX40 expression on peripheral blood mononuclear cells than healthy controls. As such, the OX40-OX40L pathway is a potential target for AD treatment. Novel therapies targeting the OX40 pathway are currently in development, several of which have demonstrated promising safety and efficacy results in patients with moderate-to-severe AD. Herein, we review the function of OX40 and the OX40-OX40L signaling pathway, their role in AD pathogenesis, and emerging therapies targeting OX40-OX40L that may offer insights into the future of AD management.

Identifying Children at Risk of Growth and Nutrient Deficiencies in the Food Allergy Clinic

BACKGROUND

Food allergies affect growth in children by decreasing the availability of nutrients through decreased dietary intake, increased dietary needs, food-medication interactions, and psychosocial burden. Guidelines on food allergy management frequently recommend nutrition counseling and growth monitoring of children with food allergies.

OBJECTIVE

To provide clear guidance for clinicians to identify children with food allergies who are at nutritional risk and ensure prompt intervention.

METHODS

We provide a narrative review summarizing information from national and international guidelines, retrospective studies, population studies, review articles, case reports, and case series to identify those with food allergy at greatest nutritional risk, determine the impact of nutritional interventions on growth, and develop guidance for risk reduction in children with food allergies.

RESULTS

Children with food allergies are at increased risk of nutritional deficiencies and poor growth. Nutritional assessment and intervention can improve outcomes. Identifying poor growth is an important step in the nutrition assessment. Therefore, growth should be assessed at each allergy evaluation. Interventions to ensure adequate dietary intake for growth include appropriately prescribed elimination diets, breast-feeding support and assessment, supplemental formula, vitamin and/or mineral supplementation, appropriate milk substitutes, and timely introduction of nutrient-dense complementary foods. Access to foods of appropriate nutritional value is an ongoing concern.

CONCLUSION

Nutrition intervention or referral to registered dietitian nutritionists with additional training and/or experience in food allergy may result in improved growth and nutrition outcomes.

Olea europaea L-derived secoiridoids: Beneficial health effects and potential therapeutic approaches

Over the years, health challenges have become increasingly complex and global and, at the beginning of the 21st century, chronic diseases, including cardiovascular, neurological, and chronic respiratory diseases, as well as cancer and diabetes, have been identified by World Health Organization as one of the biggest threats to human health. Recently, antimicrobial resistance has also emerged as a growing problem of public health for the management of infectious diseases. In this scenario, the exploration of natural products as supplementation or alternative therapeutic options is acquiring great importance, and, among them, the olive tree, Olea europaea L, specifically leaves, fruits, and oil, has been increasingly investigated for its health promoting properties. Traditionally, these properties have been largely attributed to the high concentration of monounsaturated fatty acids, although, in recent years, beneficial effects have also been associated to other components, particularly polyphenols. Among them, the most interesting group is represented by Olea europaea L secoiridoids, comprising oleuropein, oleocanthal, oleacein, and ligstroside, which display anti-inflammatory, antioxidant, cardioprotective, neuroprotective and anticancer activities. This review provides an overview of the multiple health beneficial effects, the molecular mechanisms, and the potential applications of secoiridoids from Olea europaea L.

Atopic Dermatitis and the Risk of Infection in End-Stage Renal Disease

Background and Objectives: Atopic dermatitis (AD), also known as eczema, is a common chronic inflammatory skin condition affecting 16.5 million adults in the United States. AD is characterized by an impaired epidermal barrier that can predispose individuals to infection. End-stage renal disease (ESRD) is also commonly complicated by infections due to chronic vascular access and immune-system dysfunction, possibly related to uremia. Multiple studies have reported that renal disease is a common comorbidity in adults with atopic dermatitis. The aim of this study was to determine whether AD is a risk factor for certain infections in patients with ESRD. Materials and Methods: Using the United States Renal Data System, a retrospective cohort analysis was conducted on adult ESRD patients initiating dialysis between 2004 and 2019 to investigate associations between infections and AD in this population. Results: Of 1,526,266 patients, 2290 were identified with AD (0.2%). Infectious outcomes of interest were bacteremia, septicemia, cellulitis, herpes zoster, and conjunctivitis. In all infectious outcomes except for conjunctivitis, patients with the infectious outcomes were more likely to carry a diagnosis of AD. After controlling for demographic and clinical covariates, AD was associated with an increased risk of cellulitis (adjusted relative risk (aRR) = 1.39, 95% confidence interval (CI) = 1.31-1.47) and herpes zoster (aRR = 1.67, CI = 1.44-1.94), but not with bacteremia (aRR = 0.96, CI = 0.89-1.05), septicemia (aRR = 1.02, CI = 0.98-1.08), or conjunctivitis (aRR = 0.97, CI = 0.740-1.34). Conclusions: Overall, after controlling for demographic and clinical covariates and adjusting for person-years-at-risk, AD was associated with an increased risk for some, but not all, infections within the population of patients with ESRD.

Cellular Mechanisms of Psoriasis Pathogenesis: A Systemic Review

Psoriasis is a common inflammatory skin disease characterized by abnormal proliferation of epidermal keratinocytes and massive infiltration of inflammatory cells. Many kinds of cells, including keratinocytes, T lymphocytes, dendritic cells, neutrophils, and macrophages, are reported to play critical roles in the pathogenesis and progression of psoriasis. However, to date, the role of each kind of cell in the pathogenesis and development of psoriasis has not been systematically reviewed. In addition, although antibodies developed targeting cytokines (e.g. IL-23, IL-17A, and TNF-α) released by these cells have shown promising results in the treatment of psoriasis patients, these targeted antibodies still do not cure psoriasis and only provide short-term relief of symptoms. Furthermore, long-term use of these antibodies has been reported to have adverse physical and psychological effects on psoriasis patients. Therefore, gaining a deeper understanding of the cellular and molecular pathogenesis of psoriasis and providing new thoughts on the development of psoriasis therapeutic drugs is of great necessity. In this review, we summarize the roles of various cells involved in psoriasis, aiming to provide new insights into the pathogenesis and development of psoriasis at the cellular level and hoping to provide new ideas for exploring new and effective psoriasis treatments.

Atopic Dermatitis and the Risk of Myocardial Infarction and All-Cause Mortality: A Nationwide Population-Based Cohort Study

PURPOSE

Atopic dermatitis (AD) is a chronic inflammatory skin disorder associated with various comorbidities. However, inconsistent results on the risk of myocardial infarction (MI) and mortality have been reported in patients with AD. This study was aimed to evaluate the risk of MI and all-cause mortality in patients with AD.

METHODS

This nationwide population-based retrospective cohort study enrolled 56,205 adults ≥ 20 years of age with AD and 3,825,609 controls without AD from the Korean National Health Service (NHIS) database from 2009 to 2016.

RESULTS

The risk of MI (adjusted hazard ratio [aHR], 1.111, 95% confidence interval [CI], 1.050-1.176) was increased in patients with AD. By AD severity, patients with moderate-to-severe AD had a higher risk of MI (aHR, 1.163, 95% CI, 1.080-1.251) than individuals without AD. The risk of all-cause mortality was only increased for patients with moderate-to-severe AD (aHR, 1.096, 95% CI, 1.040-1.155) compared to individuals without AD. In subgroup analysis, an increased risk of MI was observed in female, non-obese, non-smoking, non-diabetic, and non-dyslipidemic patients with moderate-to-severe AD compared to individuals without AD. An increased risk of all-cause mortality was observed in patients with moderate-to-severe AD compared to non-AD controls among individuals ≥60 years of age and non-smokers.

CONCLUSIONS

The risk of MI and all-cause death was increased in patients with moderate-to-severe AD. Even without well-known risk factors for MI and mortality, patients with AD require the proper management and screening for comorbidities to prevent MI and decrease all-cause mortality.

Association between macrophage migration inhibitory factor-173G/C polymorphism and psoriasis risk: A meta-analysis

Background The association between macrophage migration inhibitory factor (MIF)-173G/C polymorphism and psoriasis risk has been reported in several studies with inconsistent conclusions. Aims This study aims to obtain a more convincing estimate of the relationship between the MIF-173G/C polymorphism and psoriasis risk. Methods Web of Science, EMBASE, PubMed, Wan Fang Database and Chinese National Knowledge Infrastructure (CNKI) were searched up to September 2021 and eligible studies were collected. The pooled odds ratios with 95% confidence intervals were calculated to estimate the effects of MIF-173G/C polymorphism on psoriasis risk under different genetic models. All analyses were conducted using the STATA12.0 software. Results A total of 1101 psoriasis cases and 1320 healthy controls from 6 relevant studies were included in this meta-analysis. Pooled analysis suggested that MIF-173G/C polymorphism was associated with increased psoriasis risk under the allelic model (C vs. G: odds ratio = 1.30, 95% confidence interval = 1.04-1.63, P = 0.020), heterozygous model (GC vs. GG: odds ratio = 1.53, 95% confidence interval = 1.05-2.22, P = 0.027) and dominant model (CC + GC vs. GG: odds ratio = 1.51, 95% confidence interval = 1.05-2.18, P = 0.027). Limitation Very few studies on the MIF-173G/C polymorphism in psoriasis have been reported till now, thus the number of studies included in the present meta-analysis was relatively small. Due to the number of studies being relatively small and the lack of raw data, stratified analysis by ethnicity or type of psoriasis was not carried out. Conclusion This meta-analysis demonstrated that MIF-173G/C polymorphism might be related to psoriasis risk. Carriers of the C allele and the GC genotype might have higher odds to present with psoriasis.

Disease modification in inflammatory skin disorders: opportunities and challenges

Progress in understanding of the mechanisms underlying chronic inflammatory skin disorders, such as atopic dermatitis and psoriasis vulgaris, has led to new treatment options with the primary goal of alleviating symptoms. In addition, this knowledge has the potential to inform on new strategies aimed at inducing deep and therapy-free remission, that is, disease modification, potentially impacting on associated comorbidities. However, to reach this goal, key areas require further exploration, including the definitions of disease modification and disease activity index, further understanding of disease mechanisms and systemic spillover effects, potential windows of opportunity, biomarkers for patient stratification and successful intervention, as well as appropriate study design. This Perspective article assesses the opportunities and challenges in the discovery and development of disease-modifying therapies for chronic inflammatory skin disorders.

Therapeutic Effect of Dupilumab on Systemic and Vascular Inflammation in Adults with Severe Atopic Dermatitis: Feasibility Study Using 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography

Atopic dermatitis (AD) is an inflammatory skin disease associated with increased systemic and vascular inflammation. Although dupilumab has been proven to be effective against severe AD, imaging studies analysing its inflammation-reducing effect have rarely been reported. The aim of this study was to evaluate the effect of dupilumab on systemic and vascular inflammation in adult patients with severe AD, using 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT). A total of 33 adult patients with severe AD and 25 healthy controls underwent 18F-FDG PET/CT at baseline. Patients on dupilumab treatment underwent 18F-FDG PET/CT again after achieving a 75% reduction from baseline on the Eczema Area and Severity Index (EASI-75). Patients with AD exhibited increased 18F-FDG uptake values in the liver, spleen, pancreas, and carotid artery compared with healthy controls. However, compared with baseline, there was no statistically significant difference in 18F-FDG uptake in major organs and arteries after achieving EASI-75 with dupilumab treatment. In conclusion, while dupilumab treatment resulted in a significant clinical improvement and reduced serum inflammatory markers in adult patients with severe AD, no changes in systemic and vascular inflammation were observed on 18F-FDG PET/CT imaging.

Induction of psoriasis- and atopic dermatitis-like phenotypes in 3D skin equivalents with a fibroblast-derived matrix

Skin homeostasis is a complex regulated process relying on the crosstalk of keratinocytes, fibroblasts and immune cells. Imbalances of T-cell subsets and the cytokine environment can lead to inflammatory skin diseases such as psoriasis (Ps) and atopic dermatitis (AD). Modern tissue engineering provides several in vitro models mimicking Ps and AD phenotypes. However, these models are either limited in their pathological features, life span, sample availability, reproducibility, controlled handling or simplicity. Some models further lack intensive characterization as they solely focus on differentiation and proliferation aspects. This study introduces a self-assembly model in which the pathological T-cell-signalling of Ps and AD was simulated by subcutaneous Th1 and Th2 cytokine stimulation. The self-established dermal fibroblast-derived matrices of these models were hypothesized to be beneficial for proximal cytokine signalling on epidermal keratinocytes. Comprehensive histological and mRNA analyses of the diseased skin models showed a weakened barrier, distinct differentiation defects, reduced cellular adhesion, inflammation and parakeratosis formation. A keratin shift of declining physiological cytokeratin-10 (CK10) towards increasing inflammatory CK16 was observed upon Th1 or Th2 stimulation. Antimicrobial peptides (AMPs) were upregulated in Ps and downregulated in AD models. The AD biomarker genes CA2, NELL2 and CCL26 were further induced in AD. While Ps samples featured basal hyperproliferation, cells in AD models displayed apoptotic signs. In accordance, these well-controllable three-dimensional in vitro models exhibited Ps and AD-like phenotypes with a high potential for disease research and therapeutic drug testing.

Skin Ageing: A Progressive, Multi-Factorial Condition Demanding an Integrated, Multilayer-Targeted Remedy

Of the human organs, skin is the most visible one that displays the manifestations of ageing. It has a very intricate microanatomical structure and performs several key physiological functions. The pathophysiology of cutaneous ageing is characterized by deterioration of structural stability and functional integrity, implying a continuous reduction in maximal function and reserve capacity, as a result of the accumulating damage due to both intrinsic and extrinsic factors. Elimination of unfavorable expressions associated with facial and cutaneous ageing is the key patient demand in aesthetic dermatology. Even though the progress has been made in nonsurgical therapies like fillers and lasers, non-invasive interventions by using skin care products designed for rejuvenation at an early stage are the most popular and accessible solution among people. In this review, we have scrutinized the ageing-associated cutaneous changes at molecular, cellular and tissue levels. To optimize the ageing process towards a healthy skin, we propose an integrated, multilayer-targeted intervention, which involves both topical application of anti-ageing formulations from outside and oral supplementation from inside. Additionally, several promising naturally derived ingredients are reviewed from an anti-aging perspective. Most of them possess various bioactivities and may contribute to the development of the mentioned anti-ageing remedy.

Atopic Dermatitis: Clinical Aspects and Unmet Needs

Atopic dermatitis is a common chronic-relapsing, inflammatory and itchy eczematous skin disorder which occurs in both children and adults. AD pathogenesis is complex and several factors are implicated. Pruritus plays a pivotal role in disease's burden, significantly worsening atopic patient quality of life by limiting productivity and daily activities. AD diagnosis relies still on the experience of the healthcare professional and there are several unmet needs as for the diagnostic criteria, the management and the recognition of the burden of the disease. In this paper we present an indeep focus on the main clinical features of AD and the major unmet needs that should be addressed in the next research.

Chemokine Profile in Psoriasis Patients in Correlation with Disease Severity and Pruritus

Psoriasis (PsO) is a chronic, immune-mediated, inflammatory skin disease associated in most cases with pruritus. Chemokines seem to play a significant role in PsO pathogenesis. The aim of the study was to analyse serum concentrations of CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, CCL5/RANTES, CCL17/TARC, CCL18/PARC, CCL22/MDC and CXCL8/IL-8, and their correlation with PsO severity and pruritus intensity. The study included 60 PsO patients and 40 healthy volunteers. Serum concentrations of six (CCL2/MCP-1, CCL3/MIP-1α, CCL5/RANTES, CCL17/TARC, CCL18/PARC and CCL22/MDC) out of eight analysed chemokines were significantly elevated in PsO patients; however, they did not correlate with disease severity. The serum level of CCL5/RANTES was significantly higher in patients with the psoriasis area and severity index (PASI) ≥ 15 (p = 0.01). The serum concentration of CCL17/TARC correlated positively with pruritus assessed using the visual analogue scale (VAS) (R = 0.47; p = 0.05). The study indicated CCL17/TARC as a potential biomarker of pruritus intensity in PsO patients. Chemokines appear to be involved in the development of PsO systemic inflammation. Further detailed studies on the interactions between chemokines, proinflammatory cytokines and immune system cells in PsO are required to search for new targeted therapies.

Elevation of IgE in patients with psoriasis: Is it a paradoxical phenomenon?

Immunoglobulin E (IgE) elevation is a hallmark of allergic conditions such as atopic dermatitis (AD). The pathogenesis of AD is typically associated with high levels of IL-4 and IL-13 produced by activated T helper 2 (Th2) cells. Psoriasis, on the other hand, is an inflammatory skin disease mainly driven by Th17 cells and their related cytokines. Although the immunopathologic reactions and clinical manifestations are often easily distinguished in the two skin conditions, patients with psoriasis may sometimes exhibit AD-like manifestations, such as elevated IgE and persistent pruritic lesions. Given the fact that the effective T cells have great plasticity to re-differentiate in response to innate and environmental factors, this unusual skin condition could be a consequence of a cross-reaction between distinct arms of T-cell and humoral immunity. Here we review the literature concerning the roles of IgE in the development of AD and psoriasis, showing that elevated IgE seems to be an important indicator for this non-typical psoriasis.

Evaluation of the Anti-Atopic Dermatitis Effects of α-Boswellic Acid on Tnf-α/Ifn-γ-Stimulated HaCat Cells and DNCB-Induced BALB/c Mice

Boswellic acids, triterpenoids derived from the genus Boswellia (Burseraceae), are known for their anti-inflammatory and anti-tumor efficacy. Atopic dermatitis is a chronic, non-infectious inflammatory skin disease. However, the effects of α-boswellic acid on atopic dermatitis have not been studied. Therefore, in this study we examined the expression level of pro-inflammatory cytokines, histopathological analysis, and physiological data from BALB/c mice with atopic-like dermatitis induced by 2,4-dinitrochlorobenzene and TNF-α/IFN-γ-stimulated HaCaT cells to better understand the agent’s anti-atopic dermatitis efficacy. First, we found that α-boswellic reduced the epidermal thickening, mast cell numbers, and dermal infiltration of 2,4-dinitrochlorobenzene-induced atopic-like dermatitis in BALB/c mice. Furthermore, we also found that α-boswellic acid can restore transepidermal water loss and skin reddening in mice. In human keratinocytes inflamed by TNF-α/IFN-γ, α-boswellic acid inhibited MAP kinase activation and showed a reduction in NF-κB nuclear translocation. Finally, α-boswellic acid can reduce the expression level of cytokines (IL-1β, IL-6, and IL-8) following the stimulation of TNF-α/IFN-γ in HaCaT cells. Taken together, our study suggests that α-boswellic acids are a potential component for the development of anti-atopic dermatitis drugs.

The Trinity of Skin: Skin Homeostasis as a Neuro–Endocrine–Immune Organ

For a long time, skin was thought to be no more than the barrier of our body. However, in the last few decades, studies into the idea of skin as an independent functional organ have gradually deepened our understanding of skin and its functions. In this review, we gathered evidence that presented skin as a “trinity” of neuro–endocrine–immune function. From a neuro perspective, skin communicates through nerves and receptors, releasing neurotrophins and neuropeptides; from an endocrine perspective, skin is able to receive and secrete most hormones and has the cutaneous equivalent of the hypothalamic-pituitary-adrenal (HPA) axis; from an immune perspective, skin is protected not only by its physical barrier, but also immune cells and molecules, which can also cause inflammation. Together as an organ, skin works bidirectionally by operating peripheral neuro–endocrine–immune function and being regulated by the central nervous system, endocrine system and immune system at the same time, maintaining homeostasis. Additionally, to further explain the “trinity” of cutaneous neuro–endocrine–immune function and how it works in disease pathophysiology, a disease model of rosacea is presented.

Persistent eczema leads to both impaired growth and food allergy: JECS birth cohort

Skin inflammation leads to altered cytokine/chemokine production and causes systemic inflammation. The systemic mechanism of atopic dermatitis (AD) is recognized to affect systemic metabolism. This study aimed to examine the relationship between early-onset persistent eczema and body weight, height, and body mass index (BMI), in addition to food allergy in a birth cohort among infants. This study design was a nationwide, multicenter, prospective birth cohort study-the Japan Environment and Children's Study (JECS). Generalized linear models were fitted for z scores of weight, height, BMI, and food allergy to evaluate the relationship between eczema and these outcomes for infants at age1, 2, and 3 years. Persistent eczema was negatively associated with height at the age of 2 years (estimated coefficient, -0.127; 95% confidence interval [CI], -0.16 to -0.095) and 3 years (-0.177; 95% CI, -0.214 to -0.139). The same tendency was also observed with weight and BMI. Early disease onset at younger than 1 year and persistent eczema had the strongest association with development of food allergy at age 3 years (OR, 11.794; 95% CI, 10.721-12.975). One phenotype of eczema with early-onset and persistent disease creates a risk of both physical growth impairment and development of food allergy. Infants who present with the early-onset and persistent type of eczema should be carefully evaluated daily for impaired physical growth and development of food allergy.

A TCM formula VYAC ameliorates DNCB-induced atopic dermatitis via blocking mast cell degranulation and suppressing NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

A Traditional Chinese Medicine (TCM) formula (VYAC) consists of three herbs including Viola yedoensis Makino, herb (Violaceae, Viola), Sophora flavescens Aiton, root (Fabaceae, Sophora) and Dictamnus dasycarpus Turcz, root and rhizome (Rutaceae, Dictamnus), has been traditionally prescribed to treat various skin diseases in clinic.

AIM OF THE STUDY

This study aims to investigate the therapeutic effects of VYAC on the 2,4-dinitrobenzene (DNCB) induced atopic dermatitis (AD)-like mice and to explore the underlying mechanisms.

MATERIALS AND METHODS

VYAC was extracted with 70 % aqueous ethanol and lyophilized powder was used. AD-like mice were challenged by DNCB, VYAC (150 and 300 mg/kg) were oral administration daily from day 7 to day 28. At the end of experiment, the clinical scores were recorded, serum and skin in the dorsal were isolated to evaluate the therapeutic effects of VYAC. RBL-2H3 cells were stimulated with C48/80 for degranulation and plasmids expressing constitutively active form of Syk (Silence or overexpression) were transfected into RBL-2H3 cells to explore the underlying mechanisms in vitro.

RESULTS

VYAC significantly ameliorated the cardinal symptoms in the DNCB-induced AD-like mice by repairing the skin barrier function, inhibiting mast cells infiltration, restraining the serum IgE and histamine release and decreasing TNF-α, IL-4 as well as Syk mRNA level in dorsal skin and alleviating inflammation. Besides, VYAC significantly blocked RBL-2H3 cells degranulation, reduced β-hexosaminidase and histamine release, and suppressed NF-κB pathway. What's more, the degranulation of RBL-2H3 was reduced after Syk silence and increased after Syk overexpression.

CONCLUSION

Our findings clearly suggested that VYAC treat AD through inhibiting the inflammatory mediator productions and blocking mast cell degranulation via suppressing Syk mediated NF-κB pathway.

NAMPT-derived NAD+ fuels PARP1 to promote skin inflammation through parthanatos cell death

Several studies have revealed a correlation between chronic inflammation and nicotinamide adenine dinucleotide (NAD+) metabolism, but the precise mechanism involved is unknown. Here, we report that the genetic and pharmacological inhibition of nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme in the salvage pathway of NAD+ biosynthesis, reduced oxidative stress, inflammation, and keratinocyte DNA damage, hyperproliferation, and cell death in zebrafish models of chronic skin inflammation, while all these effects were reversed by NAD+ supplementation. Similarly, genetic and pharmacological inhibition of poly(ADP-ribose) (PAR) polymerase 1 (Parp1), overexpression of PAR glycohydrolase, inhibition of apoptosis-inducing factor 1, inhibition of NADPH oxidases, and reactive oxygen species (ROS) scavenging all phenocopied the effects of Nampt inhibition. Pharmacological inhibition of NADPH oxidases/NAMPT/PARP/AIFM1 axis decreased the expression of pathology-associated genes in human organotypic 3D skin models of psoriasis. Consistently, an aberrant induction of NAMPT and PARP activity, together with AIFM1 nuclear translocation, was observed in lesional skin from psoriasis patients. In conclusion, hyperactivation of PARP1 in response to ROS-induced DNA damage, fueled by NAMPT-derived NAD+, mediates skin inflammation through parthanatos cell death.

Current Concepts of Psoriasis Immunopathogenesis

Psoriasis is a recurrent, chronic, immune-mediated, systemic inflammatory disease of the skin, joints, and other organic systems. After atopic dermatitis, chronic stationary psoriasis is the most common inflammatory skin disease, affecting an average of 2-4% of the world's population. The disease carries a significant burden due to its numerous comorbidities and the major impact on patients' social and emotional aspects of life. According to current knowledge, psoriasis is a multifactorial disease that occurs in genetically predisposed individuals under various environmental factors, which trigger an immune response disorder with a series of complex inflammatory cascades. The disease is initiated and maintained by mutual interaction of the innate and adaptive immune cells, primarily dendritic cells, T lymphocytes, and keratinocytes, whose leading role alternates at different stages of the disease, consisting mainly in the IL-23/Th17 pathway. Inflammatory events result in consequent epidermal and dermal changes and evolution of the characteristic psoriatic phenotype, respectively. This paper aims to present a comprehensive overview of current knowledge on psoriasis genetic and environmental etiological factors, immunopathogenesis, and the leading cellular and cytokine participants in the inflammatory pathways of this disease.

Insulin Resistance and Metabolic Syndrome in Patients with Seborrheic Dermatitis: A Case-Control Study

Background: Our knowledge of the systemic effects of seborrheic dermatitis (SD) as a chronic inflammatory skin disease remains limited. We aimed to evaluate metabolic syndrome (MS) and glucose metabolism disorders in patients with SD. Methods: The study includes 53 patients over the age of 18 diagnosed with SD and 50 age-, gender-, and body mass index-matched healthy controls. Demographic data, anthropometric measurements, blood pressure levels, family history of SD and metabolic disorder, smoking history, and severity of the disease in SD patients were obtained. Fasting plasma glucose, insulin, hemoglobin A1c, lipid profile levels, and two-hour plasma glucose in the oral glucose tolerance test (OGTT 2-h PG), homeostasis model assessment of insulin resistance (HOMA-IR), and presence of MS were determined. Results: Weight, waist circumference, family history of SD, family history of metabolic disorder, and smoking status were significantly higher in the SD group compared with the control group (P = 0.04, P = 0.007, P = 0.004, P = 0.004, and P = 0.048, respectively). The levels of fasting plasma insulin and triglyceride, HOMA-IR and OGTT 2-h PG were also significantly higher in the SD group than in the control group (P = 0.0001, P = 0.033, P = 0.0001, and P = 0.049, respectively). In addition, the number of those with insulin resistance was significantly higher in the group with SD (n = 31, 58.49%) than in the control group (n = 11, 22%) (P = 0.0001). Although the rate of MS was higher in patients with SD (n = 12, 22.64%) than the controls (n = 6, 12%), the difference was not significant (P = 0.155). Conclusion: Our findings suggest an association between SD and insulin resistance, which may be due to their common inflammatory pathogenesis. This may be an indicator of susceptibility to diabetes, and these patients can be followed up for conditions associated with insulin resistance and encouraged to adopt a healthy lifestyle.

Unconventional treatment options in psoriasis: A review

Psoriasis is a common skin disease that affects 1-3% of the general population. The treatment depends on body surface area involved, quality of life impairment and associated comorbidities. The treatment options include topical therapy, phototherapy, conventional systemic therapy (methotrexate, cyclosporine and acitretin), biologics and oral small molecules (apremilast and tofacitinib). Despite the availability of newer therapies such as biologics and oral small molecules, many a time, there is a paucity of treatment options due to the chronic nature of the disease, end-organ toxicity of the conventional drugs or high cost of newer drugs. In these scenarios, unconventional treatment options may be utilized as stand-alone or adjuvant therapy. In this review, we have discussed these uncommonly used treatment options in the management of psoriasis.

Psoriasis and Atherosclerosis-Skin, Joints, and Cardiovascular Story of Two Plaques in Relation to the Treatment with Biologics

It is known that both psoriasis (PSO) limited to the skin and psoriatic arthritis (PSA) increase the risk of cardiovascular complications and atherosclerosis progression by inducing systemic inflammatory response. In recent decades, the introduction of biological medications directed initially against TNF-α and, later, different targets in the inflammatory cascade brought a significant breakthrough in the efficacy of PSO/PSA treatment. In this review, we present and discuss the most recent findings related to the interplay between the genetics and immunology mechanisms involved in PSO and PSA, atherosclerosis and the development of cardiac dysfunction, as well as the current PSO/PSA treatment in view of cardiovascular safety and prognosis.

Cardiovascular comorbidities of atopic dermatitis: using National Health Insurance data in Korea

Background

It is well known that atopic dermatitis (AD) is associated with other allergic diseases. Recentely, links to diseases other than allergic disease have also been actively studied. Among them, the results of studies regarding AD comorbidities, especially cardiovascular disease (CVD), have varied from country to country.

Objective

To analyze whether the risk of CVD is different between AD patients and healthy controls using Korean National Health Insurance Data.

Methods

We obtained data from 2005 to 2016 from the Korean National Health Insurance Research Database. Patients with one AD code and two AD-related tests codes were selected as AD patients, and age-and sex-matched controls to the AD patients were selected from among those without AD (1:5). Each group was investigated for accompanying metabolic syndrome (which contains hypertension, type 2 diabetes, and hyperlipidemia) and CVD (angina, myocardial infarction, peripheral vascular disease, and stroke) using ICD 10 codes.

Results

The incidence of metabolic diseases and CVD were significantly different between the AD and control groups. Using multivariable Cox regression, differences were adjusted for sex, age, and other CVD and metabolic diseases. As a result, not only metabolic disease, but also the CVD risk of AD patients was significantly higher than that of the control group. Patients with AD had as significantly higher risk of hyperlipidemia (hazard ratio [HR] = 33.02, p < 0.001), hypertension (HR = 4.86, p < 0.001), and type 2 diabetes (HR = 2.96, p < 0.001). AD patients also had a higher risk of stroke (HR = 10.61, p < 0.001), myocardial infarction (HR = 9.43, p < 0.001), angina (HR = 5.99, p < 0.001), and peripheral vascular disease (HR = 2.46, p < 0.001). Besides hyperlipidemia, there was no difference in risk according to AD severity.

Conclusion

Patients with AD have a greater risk of CVD than those without AD.

Calcium Channels: Noteworthy Regulators and Therapeutic Targets in Dermatological Diseases

Dysfunctional skin barrier and impaired skin homeostasis may lead to or aggravate a series of dermatologic diseases. A large variety of biological events and bioactive molecules are involved in the process of skin wound healing and functional recovery. Calcium ions (Ca²⁺) released from intracellular stores as well as influx through plasma membrane are essential to skin function. Growing evidence suggests that calcium influx is mainly regulated by calcium-sensing receptors and channels, including voltage-gated, transient potential receptor, store-operated, and receptor-operated calcium channels, which not only maintain cellular Ca²⁺ homeostasis, but also participate in cell proliferation and skin cell homeostasis through Ca²⁺-sensitive proteins such as calmodulin (CaM). Furthermore, distinct types of Ca²⁺ channels not merely work separately, they may work concertedly to regulate cell function. In this review, we discussed different calcium-sensing receptors and channels, including voltage-gated, transient receptor potential, store-operated, and receptor-operated calcium channels, particularly focusing on their regulatory functions and inherent interactions as well as calcium channels-related reagents and drugs, which is expected to bridge basic research and clinical applications in dermatologic diseases.

The Use of Real-World Data to Evaluate the Association Between Atopic Dermatitis and Cardiovascular Disease: A Retrospective Claims Analysis

INTRODUCTION

Atopic dermatitis (AD) is a systemic inflammatory condition that may increase the risk of cardiovascular disease (CVD); however, ongoing debate exists surrounding its direct association. We aimed to elucidate whether AD contributes to a higher incidence of CVD and major adverse cardiovascular events (MACE) in adult patients with AD, independent of metabolic disorders.

METHODS

We retrospectively analyzed a large US-based population of patients with AD (≥ 18 years of age). Logistic regression estimated the risk of CVD and MACE in adult patients with AD, independent of metabolic disorders (including diabetes, hypertension, and obesity).

RESULTS

The odds ratio (OR; 95% confidence interval [CI]) for patients without metabolic disorders was 1.25 (1.13, 1.39) for CVD and 1.22 (1.01, 1.47) for MACE. The OR (95% CI) for AD patients with metabolic disorders was 1.09 (1.07, 1.12) for CVD and 1.14 (1.09, 1.18) for MACE. This trend was even more pronounced after long-term follow-up (≥ 3 years). Lifestyle and health behavioral factors of the subjects were not available in the dataset. The lack of control for these factors could potentially confound our results.

CONCLUSIONS

Atopic dermatitis may contribute to the risk of developing CVD and MACE in adults, independent of metabolic disorders.

Comorbidities and treatment patterns in adult patients with atopic dermatitis: results from a nationwide multicenter study

Adult atopic dermatitis (adult AD) is a systemic inflammatory disorder, whose relationship with immune-allergic and metabolic comorbidities is not well established yet. Moreover, treatment of mild-to-moderate and severe atopic dermatitis needs standardization among clinicians. The aim of this study was to evaluate the distribution of comorbidities, including metabolic abnormalities, rhinitis, conjunctivitis, asthma, alopecia and sleep disturbance, according to severity of adult AD, and describe treatments most commonly used by Italian dermatologists. Retrospective, observational, nationwide study of adult patients over a 2-year period was performed. Clinical and laboratory data were obtained through review of medical records of patients aged ≥ 18 years, followed in 23 Italian National reference centres for atopic dermatitis between September 2016 and September 2018. The main measurements evaluated were disease severity, atopic and metabolic comorbidities, treatment type and duration. Six-hundred and eighty-four adult patients with AD were included into the study. Atopic, but not metabolic conditions, except for hypertension, were significantly associated with having moderate-to-severe AD in young adult patients. Disease duration was significantly associated with disease severity. Oral corticosteroids and cyclosporine were the most widely used immunosuppressant. Our study seems confirm the close relationship between adult AD and other atopic conditions, further long-term cohort studies on patients affected by adult AD need to be performed to evaluate the complex relationship between adult AD disease severity and metabolic comorbidities.

Transcriptomic analysis of atopic dermatitis in African Americans is characterized by Th2/Th17-centered cutaneous immune activation

Atopic dermatitis (AD) often presents more severely in African Americans (AAs) and with greater involvement of extensor areas. To investigate immune signatures of AD in AAs with moderate to severe pruritus, lesional and non-lesional punch biopsies were taken from AA patients along with age-, race-, and sex-matched controls. Histology of lesional skin showed psoriasiform dermatitis and spongiotic dermatitis, suggesting both Th2 and Th17 activity. Gene Set Variation Analysis showed upregulation of Th2 and Th17 pathways in both lesional versus non-lesional and lesional versus control (p < 0.01), while Th1 and Th22 upregulation were observed in lesional versus control (p < 0.05). Evidence for a broad immune signature also was supported by upregulated Th1 and Th22 pathways, and clinically may represent greater severity of AD in AA. Furthermore, population-level analysis of data from TriNetX, a global federated health research network, revealed that AA AD patients had higher values for CRP, ferritin, and blood eosinophils compared to age-, sex-, and race-matched controls as well as white AD patients, suggesting broad systemic inflammation. Therefore, AA AD patients may feature broader immune activation than previously thought and may derive benefit from systemic immunomodulating therapies that modulate key drivers of multiple immune pathways.

Noninvasive evaluation of intragraft immune responses in upper extremity transplantation

In vascularized composite allotransplantation (VCA), invasive tissue biopsies remain the gold standard in diagnosing rejection carrying significant morbidity. We aimed to show feasibility of tape-stripping for noninvasive immune monitoring in VCA. Tape-stripping was performed on allografts and native skin of upper extremity transplant recipients. Healthy nontransplanted individuals served as controls. The technique was also used in swine on naïve skin in nontransplanted animals, native skin of treated, transplanted swine, nonrejecting VCAs, and rejecting VCAs. Extracted protein was analyzed for differences in cytokine expression using Luminex technology. Significantly decreased levels of INFγ and IL-1Ra were seen between human allograft samples and native skin. In swine, rejecting grafts had increased IL-1Ra compared to naïve and native skin, decreased levels of GM-CSF compared to native skin, and decreased IL-10 compared to nonrejecting grafts. Unsupervised hierarchical clustering revealed rejecting grafts separated from the nonrejecting (P = 0.021). Variable importance in projection scores identified GM-CSF, IL-1Ra, and IL-2 as the most important profiles for group discrimination. Differences in cytokine expression are detectable in human VCA patient native skin and VCA graft skin using a noninvasive tape-stripping method. Swine studies suggest that differences in cytokines between rejecting and nonrejecting grafts are discernable.

Real-world comorbidities of atopic dermatitis in the pediatric ambulatory population in the United States

BACKGROUND

Increasing evidence has suggested the systemic nature of atopic dermatitis (AD), a common inflammatory skin condition in children. However, comprehensive analyses of real-world comorbidities in pediatric AD are limited.

OBJECTIVE

To characterize comorbidity burden in patients with AD aged <18 years old.

METHODS

The MarketScan commercial claims database was queried from January 1, 2017, to December 31, 2017. Age- and sex-matched analyses were used to compare patients with AD with general population controls.

RESULTS

A total of 86,969 pediatric patients with AD and 116,564 matched controls were identified. Increased anxiety (odds ratio [OR], 1.20) and attention-deficit hyperactivity disorder (OR, 1.11) were noted in patients with AD. In addition to dermatologic/allergic diseases, AD was also associated with infections, including methicillin-resistant Staphylococcus aureus (OR, 3.76), and autoimmune conditions, including vitiligo (OR, 2.98) and alopecia areata (OR, 4.32). Pediatric patients with AD had higher likelihoods of lymphoid/hematologic malignancies (OR, 1.94), ocular disorders (OR, 1.37-2.02), metabolic syndrome (OR, 1.61), and obesity (OR, 1.81). For all the ORs mentioned above, P was <.001.

LIMITATIONS

Retrospective analysis of health care claims data.

CONCLUSIONS

AD in pediatric patients was associated with a wide range of psychologic and systemic comorbidities. Increased awareness can help minimize its negative effects on the quality of life and prevent long-term health consequences in young patients with AD.

Non-canonical roles of NAMPT and PARP in inflammation

Nicotinamide adenine dinucleotide (NAD⁺) is the most important hydrogen carrier in cell redox reactions. It is involved in mitochondrial function and metabolism, circadian rhythm, the immune response and inflammation, DNA repair, cell division, protein-protein signaling, chromatin remodeling and epigenetics. Recently, NAD⁺ has been recognized as the molecule of life, since, by increasing NAD⁺ levels in old or sick animals, it is possible to improve their health and lengthen their lifespan. In this review, we summarize the contribution of NAD⁺ metabolism to inflammation, with special emphasis in the major NAD⁺ biosynthetic enzyme, nicotinamide phosphoribosyl transferase (NAMPT), and the NAD⁺-consuming enzyme, poly(ADP-ribose) polymerase (PARP). The extracurricular roles of these enzymes, i.e. the proinflammatory role of NAMPT after its release, and the ability of PARP to promote a novel form of cell death, known as parthanatos, upon hyperactivation are revised and discussed in the context of several chronic inflammatory diseases.

Association between rosacea and cardiovascular disease: A systematic review and meta-analysis

BACKGROUND

Rosacea and cardiovascular diseases (CVD) are chronic inflammatory disorders. While CVD is the leading cause of mortality globally, increasing evidence indicates that CVD prevalence could be higher among patients with rosacea.

AIMS

This review aimed to determine the association between the prevalence of CVD and rosacea.

PATIENTS/METHODS

A systematic review of observational studies with controls available in MEDLINE, EMBASE, PubMed, Cochrane, and Web of Science databases was conducted. We performed a pooled meta-analysis using random-effects weighting. Overall, 11 studies met the inclusion criteria, which indicated increased odds for at least one risk factor of CVD, including diabetes, high blood pressure, or dyslipidemia.

RESULTS

The pooled meta-analysis indicated an association of rosacea with higher odds of insulin resistance or diabetes (odds ratio [OR], 1.18; 95% confidence interval [CI], 0.97-1.45), high systolic blood pressure (OR, 1.96; 95% CI, 1.35-2.84), dyslipidemia (OR, 1.50; 95% CI, 1.19-1.88), and CVD (OR, 6.65; 95% CI, 2.80-15.76). No publication bias was detected. The effect of confounding factors due to overlapping symptoms and lack of individual-level data were limitations of this review.

CONCLUSION

Patients with rosacea have a high risk of CVD. However, further studies are warranted to confirm the association between rosacea and CVD.

Regulation of Skin Barrier Function via Competition between AHR Axis versus IL-13/IL-4‒JAK‒STAT6/STAT3 Axis: Pathogenic and Therapeutic Implications in Atopic Dermatitis

Atopic dermatitis (AD) is characterized by skin inflammation, barrier dysfunction, and chronic pruritus. As the anti-interleukin-4 (IL-4) receptor α antibody dupilumab improves all three cardinal features of AD, the type 2 cytokines IL-4 and especially IL-13 have been indicated to have pathogenic significance in AD. Accumulating evidence has shown that the skin barrier function is regulated via competition between the aryl hydrocarbon receptor (AHR) axis (up-regulation of barrier) and the IL-13/IL-4‒JAK‒STAT6/STAT3 axis (down-regulation of barrier). This latter axis also induces oxidative stress, which exacerbates inflammation. Conventional and recently developed agents for treating AD such as steroid, calcineurin inhibitors, cyclosporine, dupilumab, and JAK inhibitors inhibit the IL-13/IL-4‒JAK‒STAT6/STAT3 axis, while older remedies such as coal tar and glyteer are antioxidative AHR agonists. In this article, I summarize the pathogenic and therapeutic implications of the IL-13/IL-4‒JAK‒STAT6/STAT3 axis and the AHR axis in AD.

Efficacy and Safety of Biologics for Psoriasis and Psoriatic Arthritis and Their Impact on Comorbidities: A Literature Review

Psoriasis is a chronic inflammatory skin disease characterized by scaly indurated erythema. It impairs patients’ quality of life enormously. It has been recognized not only as a skin disease but as a systemic disease, since it also causes arthritis (psoriatic arthritis) and mental disorders. Furthermore, an association with cardiovascular events is indicated. With the advent of biologics, treatment of psoriasis dramatically changed due to its high efficacy and tolerable safety. A variety of biologic agents are available for the treatment of psoriasis nowadays. However, characteristics such as rapidity of onset, long-term efficacy, safety profile, and effects on comorbidities are different. Better understanding of those characteristic leads to the right choice for individual patients, resulting in higher persistence, longer drug survival, higher patient satisfaction, and minimizing the disease impact of psoriasis. In this paper, we focus on the efficacy and safety profile of biologics in psoriasis patients, including plaque psoriasis and psoriatic arthritis. In addition, we discuss the impact of biologics on comorbidities caused by psoriasis.

Interleukin-17A and Keratinocytes in Psoriasis

The excellent clinical efficacy of anti-interleukin 17A (IL-17A) biologics on psoriasis indicates a crucial pathogenic role of IL-17A in this autoinflammatory skin disease. IL-17A accelerates the proliferation of epidermal keratinocytes. Keratinocytes produce a myriad of antimicrobial peptides and chemokines, such as CXCL1, CXCL2, CXCL8, and CCL20. Antimicrobial peptides enhance skin inflammation. IL-17A is capable of upregulating the production of these chemokines and antimicrobial peptides in keratinocytes. CXCL1, CXCL2, and CXCL8 recruit neutrophils and CCL20 chemoattracts IL-17A-producing CCR6⁺ immune cells, which further contributes to forming an IL-17A-rich milieu. This feed-forward pathogenic process results in characteristic histopathological features, such as epidermal hyperproliferation, intraepidermal neutrophilic microabscess, and dermal CCR6⁺ cell infiltration. In this review, we focus on IL-17A and keratinocyte interaction regarding psoriasis pathogenesis.

The CCL20 and CCR6 axis in psoriasis

Psoriasis is a TNF-α/IL-23/IL-17A-mediated inflammatory skin disease that causes a significant socioeconomic burden in afflicted patients. IL-17A-producing immune cells, including Th17 cells, are crucial effector cells in the development of psoriasis. IL-17A stimulates epidermal keratinocytes to produce CCL20, which eventually recruits CCR6 + Th17 cells into the lesional skin. Thus, the CCL20/CCR6 axis works as a driving force that prepares an IL-17A-rich cutaneous milieu. In this review, we summarize the current research topics on the CCL20/CCR6 axis and the therapeutic intervention of this axis for psoriasis.

Aryl Hydrocarbon Receptor in Atopic Dermatitis and Psoriasis

The aryl hydrocarbon receptor (AHR)/AHR-nuclear translocator (ARNT) system is a sensitive sensor for small molecular, xenobiotic chemicals of exogenous and endogenous origin, including dioxins, phytochemicals, microbial bioproducts, and tryptophan photoproducts. AHR/ARNT are abundantly expressed in the skin. Once activated, the AHR/ARNT axis strengthens skin barrier functions and accelerates epidermal terminal differentiation by upregulating filaggrin expression. In addition, AHR activation induces oxidative stress. However, some AHR ligands simultaneously activate the nuclear factor-erythroid 2-related factor-2 (NRF2) transcription factor, which is a master switch of antioxidative enzymes that neutralizes oxidative stress. The immunoregulatory system governing T-helper 17/22 (Th17/22) and T regulatory cells (Treg) is also regulated by the AHR system. Notably, AHR agonists, such as tapinarof, are currently used as therapeutic agents in psoriasis and atopic dermatitis. In this review, we summarize recent topics on AHR related to atopic dermatitis and psoriasis.

The IL-13-OVOL1-FLG axis in atopic dermatitis

Despite sharing interleukin-4 receptor α (IL-4Rα) in their signaling cascades, IL-4 and IL-13 have different functions in atopic inflammation. IL-13 preferentially participates in the peripheral tissues because tissue-resident group 2 innate lymphoid cells produce IL-13 but not IL-4. In contrast, lymph node T follicular helper cells express IL-4 but not IL-13 to regulate B-cell immunity. The dominant microenvironment of IL-13 is evident in the lesional skin of atopic dermatitis (AD). The IL-13-rich local milieu causes barrier dysfunction by down-regulating the OVOL1-filaggrin (FLG) axis and up-regulating the periostin-IL-24 axis. Genome-wide association studies also point to the crucial involvement of the IL-13, OVOL1 and FLG genes in the pathogenesis of AD. Biologics targeting IL-13, such as the anti-IL-4Rα antibody dupilumab and the anti-IL-13 antibody tralokinumab, successfully improve AD lesions and further highlight the importance of IL-13 in the pathogenesis of AD.

Metabolic syndrome and inflammatory skin conditions

PURPOSE OF REVIEW

Several chronic inflammatory skin disorders have been linked to metabolic syndrome (MetS) and an increased risk for cardiovascular disease. In this review, we will summarize the recent evidence on the association between psoriasis, hidradenitis suppurativa (HS), and atopic dermatitis (AD) and metabolic syndrome with careful attention to this association among the pediatric population.

RECENT FINDINGS

Historically, psoriasis has exhibited the most robust association with MetS in the literature. Recent studies show that the prevalence of MetS appears to be higher among patients with HS and can be associated with MetS even in mild disease. A relationship between AD and MetS is still under debate, but research has shown a clear link between pediatric AD and being overweight or obese.

SUMMARY

There are no current consensus guidelines for metabolic syndrome in the pediatric population, and its clinical implications in children are still unclear. Nevertheless, providers should be aware of the shared underlying inflammatory state and link between several cutaneous disorders and metabolic syndrome. Early diagnosis and proper disease management of these at risk populations has the potential to assist in disease control and mitigate future cardiovascular disease.

Skin disease related to metabolic syndrome in women

Sex hormones are involved in pathways of metabolic syndrome (MetS), an observation supported by animal studies. The relationships of sex hormones with components of MetS, such as insulin resistance and dyslipidemia, have been studied in pre- and postmenopausal women. High testosterone, low sex hormone-binding globulin, and low estrogen levels increase the risks of MetS and type 2 diabetes in women. Cutaneous diseases that are sex hormone mediated, such as polycystic ovary syndrome, acanthosis nigricans, acne vulgaris, and pattern alopecia, have been associated with insulin resistance and increased risk for MetS. Furthermore, inflammatory skin conditions, such as hidradenitis suppurativa and psoriasis, increase the risk for MetS. Patients with such skin conditions should be followed for metabolic complications, and early lifestyle interventions toward these populations may be warranted.

Atopic Eczema: Genetic Analysis of COL6A5, COL8A1, and COL10A1 in Mediterranean Populations

To date, the genes associated with susceptibility to Atopic Eczema (AE) are mainly implicated in immunity, inflammation, and maintenance of skin barrier. Little is known about the possible relationship between genes modulating Extra-Cellular Matrix (ECM) and AE etiopathogenesis. In this regard, the primary objective of the present study has been the investigation of susceptibility biomarkers localized within genes encoding collagen proteins. Several studies have shown that polymorphisms within the genes encoding such proteins may generate abnormal connective tissues, making them more susceptible to mechanical stress, loss of epidermal integrity, and aging. We therefore decided to investigate three polymorphisms located in COL6A5, COL8A1, and COL10A1 as potential susceptibility biomarkers for AE in a cohort of 1470 subjects of Mediterranean origin. The genes of interest have been selected considering that the ECM and immune/inflammatory response are strongly dysregulated in AE and other complex disorders. The study confirmed that the susceptibility to AE depends on a complex interaction between latitude, geographical localization, and the differential distribution of genetic variants among populations exposed to similar environmental factors.

The contribution of IL-17 to the development of autoimmunity in psoriasis

Psoriasis is an (auto)immune-mediated disease that manifests as widespread desquamative erythema. The TNF-α/IL-23/IL-17A axis is crucial to its pathogenesis, which is demonstrated by its excellent therapeutic response to biologics that target this axis. There is a strong association between HLA-C*0602 and psoriasis, and researchers have identified autoantigens that are restricted to this major histocompatibility class I molecule. These auto-Ags include LL-37, A disintegrin and metalloprotease domain containing thrombospondin type 1 motif-like 5 (ADAMTSL5), and keratin 17. IL-17A-producing T cells have been identified in T cell populations that are reactive to these auto-Ags. In addition, lipid Ags have surfaced as candidate auto-Ags that activate IL-17A-producing T cells in a CD1a-restricted manner. In this article, we review the candidate auto-Ags that may contribute to the activation of the IL-17A-deviated immune response in psoriasis.