Atopic Dermatitis and Psoriasis as Overlapping Syndromes

Potential Aspects of the Use of Cytokines in Atopic Dermatitis

Atopic dermatitis (AD) is an abnormal inflammatory response in the skin to food, environmental IgE, or non-IgE allergens. This disease belongs to a group of inflammatory diseases that affect both children and adults. In highly developed countries, AD is diagnosed twice as often in children than in adults, which may possibly be connected to increased urbanization. The immune system's pathomechanisms of AD involve humoral mechanisms with IgE, cellular T lymphocytes, dendritic cells occurring in the dermis, Langerhans cells occurring in the epidermis, and other cells infiltrating the site of inflammation (eosinophils, macrophages, mast cells, neutrophils, and basophils). Cytokines are small proteins that affect the interaction and communication between cells. This review characterizes cytokines and potential aspects of the treatment of atopic dermatitis, as well as new strategies that are currently being developed, including targeting cytokines and their receptors.

Psoriasis dermatitis: a new entity or a different phenotypic expression of psoriasis and atopic dermatitis?

BACKGROUND

Psoriasis (P) and atopic dermatitis (AD) share some common characteristics. The resulting clinical picture with shared manifestations is a new entity called psoriasis dermatitis (PD), atopic psoriasis or psorema. The purpose of this study was to identify the clinical manifestations of this new dermatological condition, focusing on the adult population.

METHODS

We recruited adult patients from two outpatient clinics, the "severe psoriasis" and the "adult atopic dermatitis," between January 1st, 2021, and December 31st, 2021. The 26 patients meeting the inclusion criteria were followed for 12 months, and two control groups of patients were enrolled in the same period.

RESULTS

The frequencies of the variables examined within the patients affected by PD were compared with those of P or AD group. The age at disease onset was significantly higher in PD patients and the duration of symptoms was also significantly lower in PD patients, compared to both P and AD groups. Affected areas were similar between PD and P, instead the scalp, feet and genitals were more frequently involved in the PD group than in the AD group.

CONCLUSIONS

P and AD seem part of a spectrum rather than a dichotomy, where PD is an entity in the middle of this spectrum.

High-throughput proteomic analysis of chronic inflammatory skin diseases: Psoriasis and atopic dermatitis

Common characteristics in the pathogenesis of psoriasis (PS) and atopic dermatitis (AD) have been presumed, but only a few studies have clearly supported this. The current aim was to find possible similarities and differences in protein expression patterns between these two major chronic inflammatory skin diseases. High-throughput tandem mass spectrometry proteomic analysis was performed using full thickness skin samples from adult PS patients, AD patients and healthy subjects. We detected a combined total of 3045 proteins in the three study groups. According to principal component analysis, there was significant overlap between the proteomic profiles of PS and AD, and both clearly differed from that of healthy skin. The following validation of selected proteins with western blot analysis showed similar tendencies in expression levels and produced statistically significant results. The expression of periostin (POSTN) was consistently high in AD and very low or undetectable in PS (5% FDR corrected p < 0.001), suggesting POSTN as a potential biomarker to distinguish these diseases. Immunohistochemistry further confirmed higher POSTN expression in AD compared to PS skin. Overall, our findings support the concept that these two chronic skin diseases might share considerably more common mechanisms in pathogenesis than has been suspected thus far.

Skin barrier-inflammatory pathway is a driver of the psoriasis-atopic dermatitis transition

As chronic inflammatory conditions driven by immune dysregulation are influenced by genetics and environment factors, psoriasis and atopic dermatitis (AD) have traditionally been considered to be distinct diseases characterized by different T cell responses. Psoriasis, associated with type 17 helper T (Th17)-mediated inflammation, presents as well-defined scaly plaques with minimal pruritus. AD, primarily linked to Th2-mediated inflammation, presents with poorly defined erythema, dry skin, and intense itching. However, psoriasis and AD may overlap or transition into one another spontaneously, independent of biological agent usage. Emerging evidence suggests that defects in skin barrier-related molecules interact with the polarization of T cells, which forms a skin barrier-inflammatory loop with them. This loop contributes to the chronicity of the primary disease or the transition between psoriasis and AD. This review aimed to elucidate the mechanisms underlying skin barrier defects in driving the overlap between psoriasis and AD. In this review, the importance of repairing the skin barrier was underscored, and the significance of tailoring biologic treatments based on individual immune status instead of solely adhering to the treatment guidelines for AD or psoriasis was emphasized.

Psoriasis dermatitis, a common phenotype of early forms of both psoriasis and atopic dermatitis in children: A prospective multicenter study

BACKGROUND

Psoriasis (Ps) and atopic dermatitis (AD) are chronic systemic immune-mediated diseases that can coexist in an overlapping condition called psoriasis dermatitis (PD). PD patients have intermediate lesions with characteristics of both Ps and AD. PD is very rare in adults but much more frequent in children. Little is known, however, about the course of PD in the pediatric population. The aim of this study was to evaluate the percentage of PD cases in children that evolved to a definite form of Ps or AD and to identify any clinical or epidemiological variables that could predict the course of the disease.

METHODS

We performed a prospective multicenter cohort study of children diagnosed with PD between January 2018 and December 2020. We collected participants' clinical and epidemiological characteristics, and pediatric dermatologists determined the percentage of participants who developed Ps or AD.

RESULTS

The study included 24 children with PD, with a median age of 7.0 years. After a median follow-up period of 31 months, 83.3% of cases had evolved to a definite form of Ps or AD (44.4% to Ps and 38.9% to AD). Younger age and family history of Ps were associated with progression to AD. Participants who progressed to AD or Ps had a longer follow-up than those with an unchanged PD diagnosis.

CONCLUSIONS

Given sufficient time, a large percentage of PD cases in children will evolve into Ps or AD. Long-term clinical follow-up is necessary for a correct diagnosis.

Application of JAK inhibitors in paradoxical reaction through immune-related dermatoses

Biologics play a positive and effective role in the treatment of immune-related dermatoses. However, many other immune-related diseases have also manifested along with biologics treatment. Paradoxical reaction through immune-related dermatoses refer to the new onset or exacerbation of other immune-mediated dermatoses (mainly psoriasis and atopic dermatitis) after biologics treatment of inflammatory dermatoses (mainly psoriasis and atopic dermatitis), such as new atopic dermatitis (AD) in psoriasis (PsO) treatment and new PsO in AD treatment. A common genetic background and Inflammatory pathway are possible pathogenesis. Faced with paradoxical reactions, the choice of therapy needs to be directed toward therapies effective for both diseases, such as Janus kinase (JAK) inhibitors. The Janus kinase and signal transducer and activator of transcription (JAK-STAT) pathway plays an important role in the inflammatory pathway, and has been widely used in the treatment of AD and PsO in recent years. This article focuses on JAK inhibitors such as tofacitinib, baricitinib, ruxolitinib, Abrocitinib, upadacitinib, and deucravacitinib, to explore the possible application in treatment of paradoxical reactions. Common side effects, baseline risk factors and safety use of JAK inhibitors were discussed.

Atopic Dermatitis Severity and Risk for Psoriasis: A Nationwide Population-Based Study

INTRODUCTION

As research on the role of the Th17/IL-23 pathway gains importance, the relationship between atopic dermatitis (AD) and psoriasis is becoming elucidated.

OBJECTIVE

The objective of this study wasto evaluate whether AD and its severity affect the risk for psoriasis.

METHODS

This retrospective population-based study used the database from the 2009 National Health Insurance Services-Health Screening Cohort in Korea. A total of 3,957,922 adult subjects were included and observed until 2018. The primary outcome was newly diagnosed psoriasis.

RESULTS

After adjusting for possible confounding factors, the moderate-to-severe AD group had the highest hazard ratio (HR) for psoriasis (HR = 2.50; 95% confidence interval (CI), 2.40-2.61), followed by the mild AD group (HR = 2.31; 95% CI: 2.19-2.44) compared with the non-AD group during a median 8.11 ± 1.19 years of follow-up.

LIMITATIONS

It is difficult to define AD, which is not standardized, using a claims database and exclude patients who were misdiagnosed with AD.

CONCLUSION

Patients with severe AD showed an increased risk for psoriasis compared to controls, and the risk for psoriasis was increased according to AD severity. This suggests that psoriasis and AD could share inflammatory, immune, and genetic features.

Development of a clinical algorithm to predict phenotypic switches between atopic dermatitis and psoriasis (the "Flip-Flop" phenomenon)

BACKGROUND

Atopic dermatitis (AD) and psoriasis vulgaris (PV) are almost mutually exclusive diseases with different immune polarizations, mechanisms and therapeutic targets. Switches to the other disease ("Flip-Flop" [FF] phenomenon) can occur with or without systemic treatment and are often referred to as paradoxical reactions under biological therapy.

METHODS

The objective was to develop a diagnostic algorithm by combining clinical criteria of AD and PV to identify FF patients. The algorithm was prospectively validated in patients enrolled in the CK-CARE registry in Bonn, Germany. Afterward, algorithm refinements were implemented based on machine learning.

RESULTS

Three hundred adult Caucasian patients were included in the validation study (n = 238 with AD, n = 49 with PV, n = 13 with FF; mean age 41.2 years; n = 161 [53.7%] female). The total FF scores of the PV and AD groups differed significantly from the FF group in the validation data (p < .001). The predictive mean generalized Youden-Index of the initial model was 78.9% [95% confidence interval 72.0%-85.6%] and the accuracy was 89.7%. Disease group-specific sensitivity was 100% (FF), 95.0% (AD), and 61.2% (PV). The specificity was 89.2% (FF), 100% (AD), and 100% (PV), respectively.

CONCLUSION

The FF algorithm represents the first validated tool to identify FF patients.

Comparative Study of Hematological Parameters and Biomarkers of Immunity and Inflammation in Patients with Psoriasis and Atopic Dermatitis

Background and Objectives: There are no studies regarding comparative analysis of hematological parameters in patients with psoriasis (PsO) and atopic dermatitis (AD), whereas studies examining serum biomarkers of immunity and inflammation in these entities are scarce and contradictory. We aimed to compare such parameters in patients with PsO and AD. Materials and Methods: Patients with PsO (n = 40) and AD (n = 40) were consecutively included in this cross-sectional study. Hematological parameters and biomarkers of immunity and inflammation (interferon-gamma (IFN-γ), interleukine (IL)-22 and C-reactive protein (CRP)) were determined. Results: While the mean corpuscular volume (MCV) was higher in the PsO group vs. the AD group (p < 0.05), there was no difference in the other examined parameters between groups. A higher neutrophil-to-lymphocyte ratio (NLR) was found in patients with AD > 50 years vs. patients with PsO of similar age (p < 0.05). Higher IL-22 levels were found in patients with AD < 50 years vs. patients with PsO of similar age (p < 0.05). Lower IL-22 levels were found in patients with AD > 50 years vs. patients with AD < 50 years (p < 0.05). Patients with PsO and with comorbidities had lower platelets (PLT), plateletcrit (PCT) and platelet-to-lymphocyte ratio (PLR), whereas lymphocytes, red cell distribution width-to-PLT ratio (RPR) and mean platelet volume/PLT ratio (MPR) were higher vs. PsO patients without comorbidities. Patients with AD and with comorbidities had lower PCT and PLR, whereas RPR was higher vs. AD patients without comorbidities. Conclusions: A higher pro-inflammatory state (i.e., higher NLR and IL-22) was found in AD vs. PsO in age-specific groups. A higher pro-inflammatory state (i.e., as reflected by platelet indexes) was found in both diseases with comorbidities.

Psoriasis associated with asthma and allergic rhinitis: a US-based cross-sectional study using the All of US Research Program

Psoriasis is a common chronic inflammatory disease with multiple known comorbidities. Increasing evidence suggests some mechanistic overlap in the immunopathogenesis of psoriasis and some cases of asthma and allergic rhinitis (AR), but the potential association between psoriasis and asthma and AR has not been thoroughly investigated. The study aimed to investigate the association between psoriasis and asthma and AR. We used data from the NIH All of US Research Program, a nationwide longitudinal cohort of US adults, collected from 2018 to present. The source population comprised a demographically and socioeconomically diverse cohort of over 300,000 Americans. We used multivariable logistic regression models to examine the association between psoriasis and asthma and AR, after adjusting for sociodemographic variables, body mass index, and smoking status. In total, 235,551 participants (mean [SD] age, 54.7 [16.6] years; 59.3% female), including 5165 individuals with psoriasis and 230,386 individuals without psoriasis, were included in our analysis. Participants with psoriasis had significantly higher prevalence of asthma (26.1% vs. 12.9%; P < 0.001) and AR (31.8% vs. 13.4%; P < 0.001) compared to participants without psoriasis. Psoriasis was significantly associated with both asthma [adjusted odds ratio (aOR) 2.22; 95% confidence interval (CI) 2.08-2.37] and AR (aOR, 2.57; 95% CI 2.42-2.73). In subgroup analyses, associations remained stable in multivariable analyses after stratification by age, sex, and income. Psoriasis is associated with both asthma and AR in our sample of US adults. Further research is needed to explore potentially unifying inflammatory pathways among psoriasis, asthma, and AR.

Pannexin 3 channels regulate architecture, adhesion, barrier function and inflammation in the skin

The channel-forming glycoprotein Pannexin 3 (PANX3) functions in cutaneous wound healing and keratinocyte differentiation, but its role in skin homeostasis through aging is not yet understood. We found that PANX3 is absent in newborn skin but becomes upregulated with age. We characterized the skin of global Panx3 knockout mice (KO) and found that KO dorsal skin showed sex-differences at different ages, but generally had reduced dermal and hypodermal areas compared to aged-matched controls. Transcriptomic analysis of KO epidermis revealed reduced E-cadherin stabilization and Wnt signaling compared to WT, consistent with the inability of primary KO keratinocytes to adhere in culture, and diminished epidermal barrier function in KO mice. We also observed increased inflammatory signaling in KO epidermis and higher incidence of dermatitis in aged KO mice compared to wildtype controls. These findings suggest that during skin aging, PANX3 is critical in the maintenance of dorsal skin architecture, keratinocyte cell-cell and cell-matrix adhesion and inflammatory skin responses.

miRNA expression profiles of the perilesional skin of atopic dermatitis and psoriasis patients are highly similar

Atopic dermatitis (AD) and psoriasis vulgaris (PV) are chronic inflammatory skin diseases with heterogeneous molecular backgrounds. MicroRNAs (miRNAs) contribute to either development or regulation of many immune system related diseases. Only few miRNA profiling studies are available for AD and no comparisons between AD and PV skin miRNA profiles have been performed recently. We conducted a miRNA profiling analysis of skin, as well as serum, from adult AD and PV patients and control individuals. 130 miRNAs were differentially expressed in AD skin, of which 77 were common differentially expressed in AD and PV. No differentially expressed miRNAs were detected in serum. Pathway analyses revealed differentially expressed miRNAs to potentially target immune-system related pathways, including TNF-α, IL-2/STAT4 and IL-6/JAK/STAT3. Additional genetic analysis of published AD GWAS dataset detected association of several target genes of differentially expressed miRNAs in skin. Moreover, miR-28-5p, miR-31-5p, miR-378a-3p and miR-203a were validated as upregulated in the skin of AD and PV patients. All validated miRNAs were reliable predictive markers for AD or PV. In conclusion, miRNA expression pattern in the skin of adult AD patients is highly similar to that of PV with multiple differentially expressed miRNAs potentially involved in the regulation of immune responses in AD and PV.

Applications of single-cell RNA sequencing in atopic dermatitis and psoriasis

Single-cell RNA sequencing (scRNA-seq) is a novel technology that characterizes molecular heterogeneity at the single-cell level. With the development of more automated, sensitive, and cost-effective single-cell isolation methods, the sensitivity and efficiency of scRNA-seq have improved. Technological advances in single-cell analysis provide a deeper understanding of the biological diversity of cells present in tissues, including inflamed skin. New subsets of cells have been discovered among common inflammatory skin diseases, such as atopic dermatitis (AD) and psoriasis. ScRNA-seq technology has also been used to analyze immune cell distribution and cell-cell communication, shedding new light on the complex interplay of components involved in disease responses. Moreover, scRNA-seq may be a promising tool in precision medicine because of its ability to define cell subsets with potential treatment targets and to characterize cell-specific responses to drugs or other stimuli. In this review, we briefly summarize the progress in the development of scRNA-seq technologies and discuss the latest scRNA-seq-related findings and future trends in AD and psoriasis. We also discuss the limitations and technical problems associated with current scRNA-seq technology.

Ta-Xi-San Suppresses Atopic Dermatitis Involved in Multitarget Mechanism Using Experimental and Network Pharmacology Analysis

Atopic dermatitis (AD) is a relapsing and chronic skin inflammation with a common incidence worldwide. Ta-Xi-San (TXS) is a Chinese herbal formula usually used for atopic dermatitis in clinic; however, its active compounds and mechanisms of action are still unclear. Our study was designed to reveal the pharmacological activities, the active compounds, and the pharmacological mechanisms of TXS for atopic dermatitis. Mice were induced by 2,4-dinitrocluorobenzene (DNCB) to build atopic dermatitis model. The pathological evaluation, enzyme-linked immunosorbent assay (ELISA), and hematoxylin and eosin (H&E) assay were performed. The UPLC-Q-Exactive-MS^E and network pharmacology analysis were performed to explore active ingredients and therapeutic mechanisms of TXS. TXS treatment decreased levels of immunoglobulin E (IgE), interleukin-4 (IL-4), and tumor necrosis factor-α (TNF-α) in serum induced by DNCB. TXS reduced scratching behavior and alleviated inflammatory pathology of skin and ear. Meanwhile, TXS decreased the spleen index and increased spleen index. The UPLC-Q-Exactive-MS^E results showed that 65 compounds of TXS were detected and 337 targets were fished. We collected 1371 AD disease targets, and the compound-target gene network reveled that the top 3 active ingredients were (−)-epigallocatechin gallate, apigenin, and esculetin, and the core target genes were PTGS2, PTGS1, and HSP90AA1. The KEGG pathway and GO analysis showed that TXS remedied atopic dermatitis via PI3K-Akt signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, and Toll-like receptor (TLR) signaling pathway with the regulation of inflammatory response and transcription. Further, we found that the targets of PTGS2 and HSP90AA1 were both elevated in ears and skin of AD model mouse; however, TXS decreased the elevated expressions of PTGS2 and HSP90AA1. Our study revealed that TXS ameliorated AD based on (−)-epigallocatechin gallate, apigenin, and esculetin via targeting PTGS2 and HSP90AA1.

Effect of herbal cream containing Fumaria officinalis and silymarin for treatment of eczema: A randomized double-blind controlled clinical trial

Objective

Atopic dermatitis (AD) is a common skin disorder with symptoms including severe pruritus and eczematous lesions. AD affects between 5 and 20% of people in their life. Silymarin (SM) is a polyphenolic flavonoid from Silybum marianum L. and has several therapeutic characteristics including antiallergic, anticancer, and anti-inflammatory properties. Fumaria officinalis is a small plant that has a high antioxidant power and modulating effects on the immune system. Therefore, the current study intended to examine the influence of these two herbs extract on severity and symptoms of AD in patients.

Materials and Methods

40 patients with mild to moderate eczema randomly received mometasone 0.1% or the herbal cream. Treatment course was 2 weeks and patients were examined before and after 2 weeks of treatment using the SCORAD system.

Results

The reduction of SCORAD score was significant in both groups (p=0.04 in the herbal group and p=0.03 in the mometasone group) but no significant difference was observed between the groups. Mean SCORAD score was 27.66±5.9 before therapy and 4.77±1.6 after therapy in the mometasone group and mean SCORAD score was 26.05±7.1 before therapy and 6.944±2.6 after therapy in the herbal group.

Conclusion

The current study indicated the impact of these two herbs extract on severity and symptoms of AD in patients; these plants may be a new treatment in reducing eczema symptoms and its problems.

Psoriasis in Pediatric Age Group

Psoriasis is a common, chronic, immune-mediated, multisystem, inflammatory disorder. It affects all age groups, including infancy. In one-third of the cases, the onset of the disease is in the first and second decades of life. Childhood psoriasis significantly affects the quality of life of the child as well as that of the entire family. Pediatric psoriasis has distinct clinical presentations and evolves with time. Like in adults, chronic plaque psoriasis has been found to be the most common type of childhood psoriasis. Psoriatic plaques in children are less pruritic, smaller and thinner with less prominent scaling. In pigmented skin, the erythema is less prominent and plaques appear violaceous or hyperpigmented. Pediatric psoriasis can be associated with arthritis, metabolic syndrome, depression and anxiety. Hence all children should be screened routinely for associated comorbidities. Management of pediatric psoriasis is challenging owing to the limitation of approved therapies. 'Proactive therapy' is a recent approach in childhood-onset psoriasis that would help to prevent the severity of flare-ups, thus improving the quality of life.

Atopic Dermatitis-Beyond the Skin

Atopic dermatitis is a chronic inflammatory disease that can arise during the first months of life or at maturity and have a significant negative impact on the quality of life. The main pathogenic mechanism is the breakdown of cutaneous barrier integrity, which is associated with systemic inflammatory immunologic disorders. Atopic dermatitis involves numerous immunologic, allergic, respiratory, and ophthalmologic comorbidities that develop through similar intricate pathogenic phenomena. The atopic march represents the evolution in time of various allergic diseases, of which food allergies often cause the first manifestations of atopy, even from a very young age. Chronic inflammation translated through specific markers, next to increased immunoglobulin E (IgE) serum levels and heterogenous clinical manifestations, argue for the inclusion of atopic dermatitis in the systemic disease category.