Navigating the evolving landscape of atopic dermatitis: Challenges and future opportunities: The 4th Davos declaration.

The 4th Davos Declaration was developed during the Global Allergy Forum in Davos which aimed to elevate the care of patients with atopic dermatitis (AD) by uniting experts and stakeholders. The forum addressed the high prevalence of AD, with a strategic focus on advancing research, treatment, and management to meet the evolving challenges in the field. This multidisciplinary forum brought together top leaders from research, clinical practice, policy, and patient advocacy to discuss the critical aspects of AD, including neuroimmunology, environmental factors, comorbidities, and breakthroughs in prevention, diagnosis, and treatment. The discussions were geared towards fostering a collaborative approach to integrate these advancements into practical, patient-centric care. The forum underlined the mounting burden of AD, attributing it to significant environmental and lifestyle changes. It acknowledged the progress in understanding AD and in developing targeted therapies but recognized a gap in translating these innovations into clinical practice. Emphasis was placed on the need for enhanced awareness, education, and stakeholder engagement to address this gap effectively and to consider environmental and lifestyle factors in a comprehensive disease management strategy. The 4th Davos Declaration marks a significant milestone in the journey to improve care for people with AD. By promoting a holistic approach that combines research, education, and clinical application, the Forum sets a roadmap for stakeholders to collaborate to improve patient outcomes in AD, reflecting a commitment to adapt and respond to the dynamic challenges of AD in a changing world.

Subcutaneous adipose tissue: Implications in dermatological diseases and beyond.

Subcutaneous adipose tissue (SAT) is the deepest component of the three-layered cutaneous integument. While mesenteric adipose tissue-based immune processes have gained recognition in the context of the metabolic syndrome, SAT has been traditionally considered primarily for energy storage, with less attention to its immune functions. SAT harbors a reservoir of immune and stromal cells that significantly impact metabolic and immunologic processes not only in the skin, but even on a systemic level. These processes include wound healing, cutaneous and systemic infections, immunometabolic, and autoimmune diseases, inflammatory skin diseases, as well as neoplastic conditions. A better understanding of SAT immune functions in different processes, could open avenues for novel therapeutic interventions. Targeting SAT may not only address SAT-specific diseases but also offer potential treatments for cutaneous or even systemic conditions. This review aims to provide a comprehensive overview on SAT's structure and functions, highlight recent advancements in understanding its role in both homeostatic and pathological conditions within and beyond the skin, and discuss the main questions for future research in the field.

Decreased skin colonization with Malassezia spp. and increased skin colonization with Candida spp. in patients with severe atopic dermatitis.

Background: Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease in which patients are sensitized towards a plethora of allergens. The hosts fungal microbiota, the mycobiota, that is believed to be altered in patients suffering from AD acts as such an allergen. The correlation context of specific sensitization, changes in mycobiota and its impact on disease severity however remains poorly understood. Objectives: We aim to enhance the understanding of the specific sensitization towards the mycobiota in AD patients in relation to their fungal skin colonization. Methods: Sensitization pattern towards the Malassezia spp. and Candida albicans of 16 AD patients and 14 healthy controls (HC) were analyzed with the newly developed multiplex-assay ALEX2® and the established singleplex-assay ImmunoCAP®. We compared these findings with the fungal skin colonization analyzed by DNA sequencing of the internal transcribed spacer region 1 (ITS1). Results: Sensitization in general and towards Malassezia spp. and C. albicans is increased in AD patients compared to HC with a quantitative difference in severe AD when compared to mild to moderate AD. Further we saw an association between sensitization towards and skin colonization with Candida spp. yet a negative correlation between sensitization towards and skin colonization with Malassezia spp. Conclusion: We conclude that AD in general and severe AD in particular is associated with increased sensitization towards the hosts own mycobiota. There is positive correlation in Candida spp. skin colonization and negative in Malassezia spp. skin colonization when compared to AD, AD severity as well as to specific sensitization patterns.

Management of Adult Patients With Drug Reaction With Eosinophilia and Systemic Symptoms: A Delphi-Based International Consensus.

Importance: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but potentially fatal drug hypersensitivity reaction. To our knowledge, there is no international consensus on its severity assessment and treatment. Objective: To reach an international, Delphi-based multinational expert consensus on the diagnostic workup, severity assessment, and treatment of patients with DRESS. Design, Setting, and Participants: The Delphi method was used to assess 100 statements related to baseline workup, evaluation of severity, acute phase, and postacute management of DRESS. Fifty-seven international experts in DRESS were invited, and 54 participated in the survey, which took place from July to September 2022. Main Outcomes/Measures: The degree of agreement was calculated with the RAND-UCLA Appropriateness Method. Consensus was defined as a statement with a median appropriateness value of 7 or higher (appropriate) and a disagreement index of lower than 1. Results: In the first Delphi round, consensus was reached on 82 statements. Thirteen statements were revised and assessed in a second round. A consensus was reached for 93 statements overall. The experts agreed on a set of basic diagnostic workup procedures as well as severity- and organ-specific further investigations. They reached a consensus on severity assessment (mild, moderate, and severe) based on the extent of liver, kidney, and blood involvement and the damage of other organs. The panel agreed on the main lines of DRESS management according to these severity grades. General recommendations were generated on the postacute phase follow-up of patients with DRESS and the allergological workup. Conclusions and Relevance: This Delphi exercise represents, to our knowledge, the first international expert consensus on diagnostic workup, severity assessment, and management of DRESS. This should support clinicians in the diagnosis and management of DRESS and constitute the basis for development of future guidelines.

Nucleic acid-based small molecules as targeted transcription therapeutics for immunoregulation.

Transcription therapy is an emerging approach that centers on identifying the factors associated with the malfunctioning gene transcription machinery that causes diseases and controlling them with designer agents. Until now, the primary research focus in therapeutic gene modulation has been on small-molecule drugs that target epigenetic enzymes and critical signaling pathways. However, nucleic acid-based small molecules have gained popularity in recent years for their amenability to be pre-designed and realize operative control over the dynamic transcription machinery that governs how the immune system responds to diseases. Pyrrole-imidazole polyamides (PIPs) are well-established DNA-based small-molecule gene regulators that overcome the limitations of their conventional counterparts owing to their sequence-targeted specificity, versatile regulatory efficiency, and biocompatibility. Here, we emphasize the rational design of PIPs, their functional mechanisms, and their potential as targeted transcription therapeutics for disease treatment by regulating the immune response. Furthermore, we also discuss the challenges and foresight of this approach in personalized immunotherapy in precision medicine.

The epithelial barrier: The gateway to allergic, autoimmune, and metabolic diseases and chronic neuropsychiatric conditions.

Since the 1960 s, our health has been compromised by exposure to over 350,000 newly introduced toxic substances, contributing to the current pandemic in allergic, autoimmune and metabolic diseases. The "Epithelial Barrier Theory" postulates that these diseases are exacerbated by persistent periepithelial inflammation (epithelitis) triggered by exposure to a wide range of epithelial barrier-damaging substances as well as genetic susceptibility. The epithelial barrier serves as the body's primary physical, chemical, and immunological barrier against external stimuli. A leaky epithelial barrier facilitates the translocation of the microbiome from the surface of the afflicted tissues to interepithelial and even deeper subepithelial locations. In turn, opportunistic bacterial colonization, microbiota dysbiosis, local inflammation and impaired tissue regeneration and remodelling follow. Migration of inflammatory cells to susceptible tissues contributes to damage and inflammation, initiating and aggravating many chronic inflammatory diseases. The objective of this review is to highlight and evaluate recent studies on epithelial physiology and its role in the pathogenesis of chronic diseases in light of the epithelial barrier theory.

Development and Validation of a Novel Score to Predict Mortality in Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: CRISTEN.

BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening, severe mucocutaneous adverse reactions. Severity prediction at early onset is urgently required for treatment. However, previous prediction scores have been based on data of blood tests. OBJECTIVE: This study aimed to present a novel score that predicts mortality in patients with SJS/TEN in the early stages based on only clinical information. METHODS: We retrospectively evaluated 382 patients with SJS/TEN in a development study. A clinical risk score for TEN (CRISTEN) was created according to the association of potential risk factors with death. We calculated the sum of these risk factors using CRISTEN, and this was validated in a multinational survey of 416 patients and was compared with previous scoring systems. RESULTS: The significant risk factors for death in SJS/TEN comprised 10 items, including patients' age of ≥65 years, ≥10% body surface area involvement, the use of antibiotics as culprit drugs, the use of systemic corticosteroid therapy before the onset, and mucosal damage affecting the ocular, buccal, and genital mucosa. Renal impairment, diabetes, cardiovascular disease, malignant neoplasm, and bacterial infection were included as underlying diseases. The CRISTEN model showed good discrimination (area under the curve [AUC] = 0.884) and calibration. In the validation study, the AUC was 0.827, which was statistically comparable to those of previous systems. CONCLUSION: A scoring system based on only clinical information was developed to predict mortality in SJS/TEN and was validated in an independent multinational study. CRISTEN may predict individual survival probabilities and direct the management and therapy of patients with SJS/TEN.

Disrupted epithelial permeability as a predictor of severe COVID-19 development.

BACKGROUND: An impaired epithelial barrier integrity in the gastrointestinal tract is important to the pathogenesis of many inflammatory diseases. Accordingly, we assessed the potential of biomarkers of epithelial barrier dysfunction as predictive of severe COVID-19. METHODS: Levels of bacterial DNA and zonulin family peptides (ZFP) as markers of bacterial translocation and intestinal permeability and a total of 180 immune and inflammatory proteins were analyzed from the sera of 328 COVID-19 patients and 49 healthy controls. RESULTS: Significantly high levels of circulating bacterial DNA were detected in severe COVID-19 cases. In mild COVID-19 cases, serum bacterial DNA levels were significantly lower than in healthy controls suggesting epithelial barrier tightness as a predictor of a mild disease course. COVID-19 patients were characterized by significantly elevated levels of circulating ZFP. We identified 36 proteins as potential early biomarkers of COVID-19, and six of them (AREG, AXIN1, CLEC4C, CXCL10, CXCL11, and TRANCE) correlated strongly with bacterial translocation and can be used to predict and discriminate severe cases from healthy controls and mild cases (area under the curve (AUC): 1 and 0.88, respectively). Proteomic analysis of the serum of 21 patients with moderate disease at admission which progressed to severe disease revealed 10 proteins associated with disease progression and mortality (AUC: 0.88), including CLEC7A, EIF4EBP1, TRANCE, CXCL10, HGF, KRT19, LAMP3, CKAP4, CXADR, and ITGB6. CONCLUSION: Our results demonstrate that biomarkers of intact or defective epithelial barriers are associated with disease severity and can provide early information on the prediction at the time of hospital admission.

Spatial transcriptomics combined with single-cell RNA-sequencing unravels the complex inflammatory cell network in atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is the most common chronic inflammatory skin disease with complex pathogenesis for which the cellular and molecular crosstalk in AD skin has not been fully understood. METHODS: Skin tissues examined for spatial gene expression were derived from the upper arm of 6 healthy control (HC) donors and 7 AD patients (lesion and nonlesion). We performed spatial transcriptomics sequencing to characterize the cellular infiltrate in lesional skin. For single-cell analysis, we analyzed the single-cell data from suction blister material from AD lesions and HC skin at the antecubital fossa skin (4 ADs and 5 HCs) and full-thickness skin biopsies (4 ADs and 2 HCs). The multiple proximity extension assays were performed in the serum samples from 36 AD patients and 28 HCs. RESULTS: The single-cell analysis identified unique clusters of fibroblasts, dendritic cells, and macrophages in the lesional AD skin. Spatial transcriptomics analysis showed the upregulation of COL6A5, COL4A1, TNC, and CCL19 in COL18A1-expressing fibroblasts in the leukocyte-infiltrated areas in AD skin. CCR7-expressing dendritic cells (DCs) showed a similar distribution in the lesions. Additionally, M2 macrophages expressed CCL13 and CCL18 in this area. Ligand-receptor interaction analysis of the spatial transcriptome identified neighboring infiltration and interaction between activated COL18A1-expressing fibroblasts, CCL13- and CCL18-expressing M2 macrophages, CCR7- and LAMP3-expressing DCs, and T cells. As observed in skin lesions, serum levels of TNC and CCL18 were significantly elevated in AD, and correlated with clinical disease severity. CONCLUSION: In this study, we show the unknown cellular crosstalk in leukocyte-infiltrated area in lesional skin. Our findings provide a comprehensive in-depth knowledge of the nature of AD skin lesions to guide the development of better treatments.

Dupilumab for Chronic Prurigo: Case Series on Effectiveness, Safety, and Quality of Life.

BACKGROUND: Chronic prurigo (CPG) is a pruritic skin disease, characterized by an itch-scratch cycle and scarring. It reduces patients' quality of life (QoL). Dupilumab is a monoclonal human IgG antibody that inhibits signaling of the interleukin 4 (IL-4) and interleukin 13 (IL-13) pathways through blockade of the IL-4 receptor. Patients with CPG who receive dupilumab often report great improvement in itch and overall QoL. We therefore reviewed our experience in order to follow up on QoL, safety, and treatment response in patients with CPG who received dupilumab. METHODS: We conducted a real-world retrospective single-center case series. Outcomes were assessed by phone interviews and photographs using validated questionnaires and scores. Demographic data were obtained from the hospital files. Follow-up was up to 2 years. We assessed QoL with the Dermatology Life Quality Index (DLQI) and the Itchy quality of life questionnaire (ItchyQoL). Numerical Rating Scale (NRS) was used to assess itch. Prurigo lesions were documented with the Prurigo activity and severity score (PAS). RESULTS: Ten patients were included in this study. Results were reported up to 2 years after treatment with dupilumab. The response variables for DLQI, ItchyQoL, NRS, and PAS analyses showed a statistically significant decrease over time (DLQI: p ≤ 0.0001 [-0.84; -1.27], ItchyQoL: p ≤ 0.0001 [-9.89; -18.69], NRS maximum and average: p ≤ 0.0001 [-0.52; -0.86] and p ≤ 0.0001 [-0.55; -0.94], and PAS number of lesions: p = 0.0005 [-1.70; -5.28]). The percent decrease after 1 year of treatment (this estimate is based on model estimates) ranges from -42% to -82%. Four (40%) patients reported mild side effects. No serious side effects were reported. CONCLUSION: Dupilumab treatment of CGP for up to 2 years is associated with improved QoL and less itching.

Atopic dermatitis: Correlation of distinct risk factors with age of onset in adulthood compared to childhood.

BACKGROUND: Atopic dermatitis (AD) has long been regarded as a primarily pediatric disease. However, there is growing evidence for a high rate of adult-onset AD. We aimed to characterize factors associated with adult-onset versus childhood-onset AD and controls. METHODS: We analyzed cross-sectional data of the CK-CARE-ProRaD cohorts Bonn, Augsburg, Davos, Zürich of 736 adult patients stratified by age of AD onset (childhood-onset <18 years: 76.4% (subsets: 0 to 2; ≥2 to 6; ≥7 to 11; ≥12 to 18); adult-onset ≥18 years: 23.6% (subsets: ≥18 to 40; ≥41 to 60; ≥61) and 167 controls (91 atopic, 76 non-atopic)). RESULTS: We identified active smoking to be associated with adult-onset AD versus controls (adjusted Odds Ratio (aOR) = 5.54 [95% Confidence Interval: 1.06-29.01] vs. controlsnon-atopic , aOR = 4.03 [1.20-13.45] vs. controlsatopic ). Conjunctivitis showed a negative association versus controlsatopic (aOR = 0.36 [0.14-0.91]). Food allergy (aOR = 2.93 [1.44-5.96]), maternal food allergy (aOR = 9.43 [1.10-80.95]), palmar hyperlinearity (aOR = 2.11 [1.05-4.25]), and academic background (aOR = 2.14 [1.00-4.54]) increased the odds of childhood-onset AD versus controlsatopic . Shared AD-associated factors were maternal AD (4-34x), increased IgE (2-20x), atopic stigmata (2-3x) with varying effect sizes depending on AD onset and control group. Patients with adult-compared to childhood-onset had doubled odds of allergic rhinitis (aOR = 2.15 [1.12-4.13]), but reduced odds to feature multiple (3-4) atopic comorbidities (aOR = 0.34 [0.14-0.84]). Adult-onset AD, particularly onset ≥61 years, grouped mainly in clusters with low contributions of personal and familial atopy and high frequencies of physical inactivity, childhood-onset AD, particularly infant-onset, mainly in "high-atopic"-clusters. CONCLUSIONS: The identified associated factors suggest partly varying endo- and exogeneous mechanisms underlying adult-onset versus childhood-onset AD. Our findings might contribute to better assessment of the individual risk to develop AD throughout life and encourage prevention by non-smoking and physical activity as modifiable lifestyle factors.

Drug reactions with eosinophilia and systemic symptoms induced by immune checkpoint inhibitors: an international cohort of 13 cases.

Among dermatologic adverse events induced by immune checkpoint inhibitors (ICI), drug reactions with eosinophilia and systemic symptoms (DRESS) have been very rarely reported. The objective of this study is to better define the clinical and histologic features, treatment and prognosis of ICI-related DRESS. This retrospective case series was conducted between 01 January 2015 and 31 December 2021 by the dermatology departments of five international networks involved in drug reactions. Inclusion criteria were age ≥18 years old, DRESS with Regiscar score ≥4 (probable or certain) and ICI as a suspect drug. Clinical, biologic and follow-up data were extracted from the medical charts. Thirteen patients were included. The median time to onset was 22 days (3-11). No patients had a high-risk drug introduced in the past 3 months. A majority of patients presented fever (92%), diffuse exanthema (77%) and facial edema (69%). Biologic features included hypereosinophilia in eight patients (61.5%), hyperlymphocytosis in 3 (23%), elevated liver function tests in 11 (85%, grade 1 or 2 in most cases) and renal involvement in 5 (38%). Two patients (15%) had lung involvement. PCR evidence of viral replication was detected in five patients (38.5%). Treatment involved discontinuation of the suspect ICI and systemic steroids with variable dose and duration regimens. Among the four patients in which ipilimumab + nivolumab combination therapy was initially suspected, one was rechallenged with nivolumab monotherapy with good tolerance. Five patients were switched to another anti-PD-1 plus low-dose systemic steroids, with good tolerance in four cases. No patient died because of DRESS. DRESS induced by ICI are rare and of moderate severity. A consensus for management is still pending.

Cell-Specific and Variant-Linked Alterations in Expression of ERAP1, ERAP2, and LNPEP Aminopeptidases in Psoriasis.

ERAP1, ERAP2, and LNPEP are aminopeptidases implicated in autoimmune pathophysiology. In this study, we show that ERAP2 is upregulated and ERAP1 is downregulated in patients with psoriasis who are homozygous for autoimmune-linked variants of ERAP. We also demonstrate that aminopeptidase expression is not uniform in the skin. Specifically, the intracellular antigen-processing aminopeptidases ERAP1 and ERAP2 are strongly expressed in basal and early spinous layer keratinocytes, whereas granular layer keratinocytes expressed predominantly LNPEP, an aminopeptidase specialized in the processing of extracellular antigens for presentation to T cells. In psoriasis, basal keratinocytes also expressed the T-cell- and monocyte-attracting chemokine, CCL2, and the T-cell-supporting cytokine, IL-15. In contrast, TGF-ß1 was the major cytokine expressed by healthy control basal keratinocytes. SFRP2-high dermal fibroblasts were also noted to have an ERAP2-high expression phenotype and elevated HLA-C. In psoriasis, the SFRP2-high fibroblast subpopulation also expressed elevated CXCL14. From these results, we postulate that (i) an increased ERAP2/ERAP1 ratio results in altered antigen processing, a potential mechanism by which ERAP risk alleles predispose individuals to autoimmunity; (ii) ERAP2-high expressing cells display a unique major histocompatibility complex-bound peptidome generated from intracellular antigens; and (iii) the granular layer peptidome is skewed toward extracellular antigens.

Assessing the Discriminatory Ability of Diagnostic Criteria for Ulcerative Pyoderma Gangrenosum and Its Mimickers.

This comparative effectiveness research study assesses the discriminatory ability of diagnostic criteria for pyoderma gangrenosum.

Viral infections and drug hypersensitivity.

Virus infections and T-cell-mediated drug hypersensitivity reactions (DHR) can influence each other. In most instances, systemic virus infections appear first. They may prime the reactivity to drugs in two ways: First, by virus-induced second signals: certain drugs like ß-lactam antibiotics are haptens and covalently bind to various soluble and tissue proteins, thereby forming novel antigens. Under homeostatic conditions, these neo-antigens do not induce an immune reaction, probably because co-stimulation is missing. During a virus infection, the hapten-modified peptides are presented in an immune-stimulatory environment with co-stimulation. A drug-specific immune reaction may develop and manifest as exanthema. Second, by increased pharmacological interactions with immune receptors (p-i): drugs tend to bind to proteins and may even bind to immune receptors. Without viral infections, this low affine binding may be insufficient to elicit T-cell activation. During a viral infection, immune receptors are more abundantly expressed and allow more interactions to occur. This increases the overall avidity of p-i reactions and may even be sufficient for T-cell activation and symptoms. There is a situation where the virus-DHR sequence of events is inversed: in drug reaction with eosinophilia and systemic symptoms (DRESS), a severe DHR can precede reactivation and viremia of various herpes viruses. One could explain this phenomenon by the massive p-i mediated immune stimulation during acute DRESS, which coincidentally activates many herpes virus-specific T cells. Through p-i stimulation, they develop a cytotoxic activity by killing herpes peptide-expressing cells and releasing herpes viruses. These concepts could explain the often transient nature of DHR occurring during viral infections and the often asymptomatic herpes-virus viraemia after DRESS.