Atopic dermatitis phenotypes and the need for personalized medicine

A comprehensive review of natural products against atopic dermatitis: Flavonoids, alkaloids, terpenes, glycosides and other compounds

Atopic dermatitis (AD) is considered a great challenge for human communities and imposes both physiological and mental burdens on patients. Natural products have widely been used to treat a wide range of diseases, including cancer, gastrointestinal diseases, asthma, neurological disorders, and infections. To seek potential natural products against AD, in the current review, we searched the terms "atopic dermatitis" and "natural product" in Pubmed, Medline, Web of Science，Science Direct, Embase, EBSCO, CINAHL, ACS. The results show that many natural products, especially puerarin, ferulic acid and ginsenosides, cound protect against AD. Meanwhile, we discussed the therapeutic mechanisms and showed that the natural products exert their anti-inflammatory effects by suppressing the quantity and activity of many inflammatory cell types and cytokines, including neutrophils, monocytes, lymphocytes, Langerhans cells, interleukins (ILs, including IL-1α, IL-1β, IL-4), TNF-α, and TSLP, IgE. via inhibition of JAK/STAT, MAPKs and NF-κB signaling pathways, thereby, halting the inflammatory cascade. Future investigations should focus on studies with more reflective of the clinical characteristics and demographics, so as to develop natural products that will be hopefully available for the treatment of human AD disease.

Repurposing Belinostat for Alleviation of Atopic Dermatitis

Atopic dermatitis (AD) is a highly prevalent chronic inflammatory skin disease that is characterized by intense pruritus, seriously affecting patients' quality of life. Its pathophysiology, which involves both the adaptive and innate immune responses as well as skin barrier defects, is still poorly understood. We recently identified a microRNA, miR-335, as a key driver of keratinocyte differentiation and cornification, which is essential for the establishment of a healthy skin barrier. However, expression of miR-335 is lost in AD, leading to barrier defect. We further demonstrated how belinostat, a histone deacetylase inhibitor, can effectively restore miR-335 and resolve the barrier defect in a dry skin model. Here, in this commentary, we highlight the role of belinostat in the treatment of AD and discuss the need for more research into crosstalk between epigenetic and non-coding RNA-based regulation, as well as possible therapeutic strategies targeting the epigenome.

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.

Use of Tape Strips to Detect Immune and Barrier Abnormalities in the Skin of Children With Early-Onset Atopic Dermatitis

Importance

Molecular profiling of skin biopsies is the criterion standard for evaluating the cutaneous atopic dermatitis (AD) phenotype. However, skin biopsies are not always feasible in children. A reproducible minimally invasive approach that can track cutaneous disease in pediatric longitudinal studies or clinical trials is lacking.

Objective

To assess a minimally invasive approach using tape strips to identify skin biomarkers that may serve as a surrogate to biomarkers identified using whole-tissue biopsies.

Design, Setting, and Participants

This cross-sectional study of 51 children younger than 5 years recruited children with moderate to severe AD and children without AD from the dermatology outpatient clinics at a children's hospital. Sixteen tape strips were serially collected from the nonlesional and lesional skin of 21 children who had AD and were less than 6 months from disease initiation and from the normal skin of 30 children who did not have AD between January 22, 2016, and April 20, 2018.

Main Outcomes and Measures

Gene and protein expression were evaluated using quantitative real-time polymerase chain reaction and immunohistochemistry.

Results

A total of 51 children younger than 5 years were included in the study; 21 children had moderate to severe AD with less than 6 months of disease duration, and 30 children did not have AD. Of the 21 children with AD, the mean (SD) age was 1.7 (1.7) years, and most were male (15 [71.4%] and white (15 [71.4%]). Of the 30 children without AD, the mean (SD) age was 1.8 (2.0) years, and most were female (20 [66.7%]) and white (22 [73.3%]). Seventy-seven of 79 evaluated immune and barrier gene products were detected (gene detection rate, 97%) in 70 of 71 tape strips (sample detection rate, 99%), with 53 of 79 markers differentiating between children with lesional and/or nonlesional AD from children without AD. Many cellular markers of T cells (CD3), AD-related dendritic cells (Fc ε RI and OX40 ligand receptors), and key inflammatory (matrix metallopeptidase 12), innate (interleukin 8 [IL-8] and IL-6), helper T cell 2 (TH2; IL-4, IL-13, and chemokines CCL17 and CCL26), and TH17/TH22 (IL-19, IL-36G, and S100A proteins) genes were significantly increased in lesional and nonlesional AD compared with tape strips from normal skin. For example, IL-4 mean (SE) for lesional was -15.2 (0.91) and normal was -19.5 (0.48); P < .001. Parallel decreases occurred in epidermal barrier gene products (FLG, CLDN23, and FA2H) and negative immune regulators (IL-34 and IL-37). For example, the decrease for FLG lesional was mean (SE) -2.9 (0.42) and for normal was 2.2 (0.45); P < .001. Associations were found between disease severity or transepidermal water loss and TH2 (IL-33 and IL-4R) and TH17/TH22 (IL-36G and S100As) products in lesional and nonlesional AD skin (evaluated using the SCORing Atopic Dermatitis, Eczema Area and Severity Index, and Pruritus Atopic Dermatitis Quickscore tools).

Conclusions and Relevance

In this study, tape strips provide a minimally invasive alternative for serially evaluating AD-associated cutaneous biomarkers and may prove useful for tracking pediatric AD therapeutic response and predicting future course and comorbidities.

New and Emerging Systemic Treatments for Atopic Dermatitis

Atopic dermatitis (AD) is a prevalent inflammatory skin condition that, depending on its severity, can cause enormous morbidity. Corticosteroids and systemic immunosuppression, traditionally standard of care for difficult-to-treat disease, have many undesirable side effects. The desire for targeted treatments along with an improved understanding of the pathophysiology of AD has spurred the development of novel treatments. In this article, we review promising new treatments and discuss how their targets—IL-13, IL-31, OX40 (CD134), and the Janus kinase family of proteins—participate in the pathogenesis of AD. We review the published phase II and III data for dupilumab, tralokinumab, lebrikizumab, nemolizumab, anti-OX40 antibody, baricitinib, abrocitinib, and upadacitinib. The introduction of new agents may offer new options, but it remains to be seen how narrow-acting agents, like single interleukin inhibitors, will compare in safety and efficacy to broad-acting agents such as JAK inhibitors.

Dupilumab-Associated Ocular Surface Disease: Clinical Characteristics, Treatment, and Follow-Up

PURPOSE

A consecutive case series of patients with dupilumab-associated ocular surface disease (DAOSD) that describes common ocular symptoms and signs, proposes a symptom disease severity grading system, and describes treatment strategies of DAOSD patients was evaluated.

METHODS

A retrospective chart review of patients with concomitant dupilumab-treated atopic dermatitis and DAOSD with ophthalmic evaluation between January 2014 and May 2019 was conducted.

RESULTS

Twenty-nine patients (mean age 46 years, M/F: 12/17) with 57 ophthalmic exams were identified. The most common ocular symptoms included irritation/pain (n = 28, 97%), redness (n = 24, 83%), pruritus (n = 18, 62%), discharge (n = 18, 62%), and light sensitivity (n = 6, 21%). The most frequent signs included conjunctival injection (n = 18, 62%), superficial punctate keratitis (n = 16, 55%), and papillary reaction (n = 8, 28%). Topical corticosteroids (TCS) (n = 23, 79%), tacrolimus (n = 6, 21%), and artificial tears (n = 7, 24%) were the most commonly used therapies. Of those with follow-up documentation (n = 21), 20 were noted to have partial or complete response with TCS based on symptoms and reduction of signs. Using our proposed symptom-based grading scale, scaled 1 to 5 based on the presence of common symptoms listed above, 66% (n = 19) requiring topical immunomodulating therapy were found in the 'severe' group (≥3 symptoms) and 17% (n = 5) were found in the 'mild' group (≤2 symptoms).

CONCLUSIONS

This study provides insight into the commonly presenting ocular signs and symptoms associated with DAOSD and highlights the efficacy of TCS and other immunomodulators in improving symptoms associated with DAOSD. Based on our findings, we propose a symptom-based grading system that can guide nonophthalmic physicians regarding ophthalmology consult.

The effects of antibiotic exposure on asthma in children with atopic dermatitis

Early-life antibiotic use is associated with allergic diseases. The risk factors for the progression from atopic dermatitis (AD) to asthma or allergic rhinitis are still unknown. We aimed to investigate the association between exposure to different antibiotics and the risk of new-onset asthma in children with AD. By using the Longitudinal Health Insurance Database 2005, we selected AD patients less than 6 years old identified by ICD-9-CM code 691.8. The case group was defined as those having new-onset asthma, and the control group was defined as those without an asthma history. Information on antibiotic exposure in the 5 years prior to the index date was collected from drug prescription records. We estimated the adjusted odds ratio by using conditional logistic regression, adjusted for age, sex, index year, other potential risk factors and antibiotics. Antibiotic exposure was associated with the development of asthma in patients with AD (aOR = 3.68, 95% CI 2.13–6.36), particularly for patients less than 5 years old (aOR = 4.14, 95% CI 2.24–7.64) (p for trend < 0.001), even though lower cumulative antibiotic defined daily doses (DDDs) were associated with new-onset asthma occurrence. Antibiotic exposure, especially macrolide exposure, is associated with an increased risk of asthma in patients with AD.

Molecular Mechanisms of Atopic Dermatitis Pathogenesis

Atopic dermatitis is a chronic, non-infectious inflammatory dermatosis. Acharacteristic feature is persistent itching of the skin. The chronic, relapsing course of the disease, economic burden, and the whole family’s involvement in the treatment process immensely reduce the quality of life of patients and their families. The disease emerges as a social problem by increasing indirect costs, such as visiting a doctor, absenteeism from work and school, and avoiding social interactions. Thepathophysiology of atopic dermatitis is complex and multifactorial. It includes genetic disorders, a defect in the epidermal barrier, an altered immune response, anddisruption of the skin’s microbial balance. The numerous complex changes at thegenetic level and innate and adaptive immunity provide the basis for characterizing the various phenotypes and endotypes of atopic dermatitis. Emerging therapies rely on the action of specific molecules involved in the disease’s pathogenesis. It may be the starting point for the individualization of atopic dermatitis treatment. This paper will try to present some molecular mechanisms of atopic dermatitis and their clinical implications.

Nomenclature and clinical phenotypes of atopic dermatitis

Atopic dermatitis is a heterogeneous disease and resists classification. In this review, we discuss atopic dermatitis nomenclature and identify morphologic phenotypes, which will facilitate correct diagnoses and development of treatment strategies. We support using the term 'atopic dermatitis' rather than eczema, because it describes the allergic background and inflammation ('itis') as drivers of the disease. Atopic dermatitis has many morphologic manifestations that vary by topographic area affected, age, or race and require consideration in differential diagnosis. Different phenotypes based on morphology and topographic location, ethnicity, and age are discussed. A better-defined phenotype identification for atopic dermatitis will facilitate earlier and correct diagnosis of this complex condition and inform selection of the most appropriate treatment choice in an era in which targeted therapies may generate more individualized patient care.

The Wound Healing Peptide, AES16-2M, Ameliorates Atopic Dermatitis In Vivo

Peptide materials have recently been considered for use in various industrial fields. Because of their efficacy, safety, and low cost, therapeutic peptides are studied for various diseases, including atopic dermatitis (AD). AD is a common inflammatory skin disease impairing the patient's quality of life. Various therapies, such as treatments with corticosteroids, calcineurin inhibitors, and antibody drugs, have been applied, but numerous side effects have been reported, including skin atrophy, burning, and infection. In the case of antibody drugs, immunogenicity against the drugs can be a problem. To overcome these side effects, small peptides are considered therapeutic agents. We previously identified the small wound healing peptide AES16-2M with a sequence of REGRT, and examined its effects on AD in this study. Interestingly, the administration of AES16-2M downregulated the AD disease score, ear thickness, serum IgE, and thymic stromal lymphopoietin (TSLP) in AD mice. The thickness of the epidermal layer was also improved by AES16-2M treatment. In addition, quantities of IL-4-, IL-13-, and IL-17-producing CD4 T cells from peripheral lymph nodes and spleens were reduced by injection of AES16-2M. Furthermore, the expression of TSLP was significantly reduced in AES16-2M-treated human keratinocytes. Therefore, these results suggest that AES16-2M can be a novel candidate for AD treatment.

Cutaneous barrier dysfunction in allergic diseases

The fundamental defect(s) that drives atopic dermatitis (AD) remains controversial. "Outside in" proponents point to the important association of filaggrin gene mutations and other skin barrier defects with AD. The "inside out" proponents derive support from evidence that AD occurs in genetic animal models with overexpression of type 2 immune pathways in their skin, and humans with gain-of-function mutations in their type 2 response develop severe AD. The observation that therapeutic biologics, targeting type 2 immune responses, can reverse AD provides compelling support for the importance of "inside out" mechanisms of AD. In this review, we propose a central role for epithelial cell dysfunction that accounts for the dual role of skin barrier defects and immune pathway activation in AD. The complexity of AD has its roots in the dysfunction of the epithelial barrier that allows the penetration of allergens, irritants, and microbes into a cutaneous milieu that facilitates the induction of type 2 immune responses. The AD phenotypes and endotypes that result in chronic skin inflammation and barrier dysfunction are modified by genes, innate/adaptive immune responses, and different environmental factors that cause skin barrier dysfunction. There is also compelling evidence that skin barrier dysfunction can alter the course of childhood asthma, food allergy, and allergic rhinosinusitis. Effective management of AD requires a multipronged approach, not only restoring cutaneous barrier function, microbial flora, and immune homeostasis but also enhancing skin epithelial differentiation.

Appearance of Acute Inflammatory State Indicates Improvement in Atopic Dermatitis Cases Under Classical Homeopathic Treatment: A Case Series

The Continuum theory and the Levels of Health theory propound the idea that return of efficient acute inflammation (high fever) heralds true improvement in chronic inflammatory states. We present 6 cases of atopic dermatitis (AD), which had stability in their improvement for 1 year or more, under classical homeopathy. The cases were retrospectively assessed with selected based on the Hanifin Rajka atopic dermatitis diagnostic criteria and the follow ups evaluated according to changes on SCORing Atopic Dermatitis scale (SCORAD) scale. The pictures are presented as evidence. Modified Naranjo Criteria for assessing causal attribution of clinical outcome to homeopathic intervention was used to assess the effect of homeopathy in these cases. All the cases improved and stabilised with complete skin clearance (those that relapsed within 1 year were not included). These patients had not suffered high fevers/acute inflammatory diseases since onset/aggravation of AD. Five of the 6 cases developed acute inflammatory diseases as the chronic condition improved. The last case showed return of an old, lesser pathology. The control cases – which were selected for non-improvement under classical homeopathy also showed remarkable skin clearance when there was appearance of acute inflammatory states. In this study, there is a mutually exclusive relationship between efficient acute inflammation and chronic inflammation, which is in accordance with the 2 theories considered here. Further scientific studies are necessary to establish the phenomenon at tissue level.

A clinico-pathological approach to management of atopic dermatitis

Recent research in atopic dermatitis (AD) has identified it to be a heterogeneous inflammatory skin disorder of different endotypes (immune polarisation of T-cell subsets and genetic mutations) underlying various phenotypes (age of onset, ethnicity, disease severity, etc.). The corresponding heterogeneity in underlying patho-mechanisms of the disease has resulted in an impetus towards an endotype-driven management of AD. We propose a practical approach that is based on classifying AD patients into intrinsic and extrinsic phenotypes and their corresponding underlying endotypes. This approach aims to provide a practical method that integrates recent understanding of AD pathogenesis for a targeted endotype-driven management of AD.

Mouse models of atopic dermatitis: a critical reappraisal

Mouse models for atopic dermatitis (AD) are an indispensable preclinical research tool for testing new candidate AD therapeutics and for interrogating AD pathobiology in vivo. In this Viewpoint, we delineate why, unfortunately, none of the currently available so-called "AD" mouse models satisfactorily reflect the clinical complexity of human AD, but imitate more "allergic" or "irriant" contact dermatitis conditions. This limits the predictive value of AD models for clinical outcomes of new tested candidate AD therapeutics and the instructiveness of mouse models for human AD pathophysiology research. Here, we propose to initiate a rational debate on the minimal criteria that a mouse model should meet in order to be considered relevant for human AD. We suggest that valid AD models should at least meet the following criteria: (a) an AD-like epidermal barrier defect with reduced filaggrin expression along with hyperproliferation, hyperplasia; (b) increased epidermal expression of thymic stromal lymphopoietin (TSLP), periostin and/or chemokines such as TARC (CCL17); (c) a characteristic dermal immune cell infiltrate with overexpression of some key cytokines such as IL-4, IL-13, IL-31 and IL-33; (d) distinctive "neurodermatitis" features (sensory skin hyperinnervation, defective beta-adrenergic signalling, neurogenic skin inflammation and triggering or aggravation of AD-like skin lesions by perceived stress); and (e) response of experimentally induced skin lesions to standard AD therapy. Finally, we delineate why humanized AD mouse models (human skin xenotransplants on SCID mice) offer a particularly promising preclinical research alternative to the currently available "AD" mouse models.

Atopic Dermatitis and Psoriasis as Overlapping Syndromes

METHODS

In this observational study, 38 children with concomitant AD and PS with a mean age of 6.5 ± 3.2 yrs were compared with 41 similar patients with AD only (5.3 ± 5.1 yrs) and 28 patients with PS only (6.4 ± 4.3 yrs). All patients underwent dermatological examinations, including determination of SCORAD and PASI scores. TNF-α, IFN-γ, IL-2, IL-4, IL-5, IL-6, IL-8, IL-12, IL-17, IL-18, IL-22, I:-33, and TARC/CCL17 were measured by ELISA according to the manufacturer's instructions.

RESULTS

Patients with concomitant AD and PS were frequently boys and overweight and had skin lesions equally distributed throughout the body. Children with concomitant AD and PS were more likely to report a family history of atopic disease than children with only AD or PS, and those with AD were more likely to report a family history of atopic disease than those with PS. Significant differences were observed in the concentration of IL-17 between patients with AD and PS and those with only AD or PS: 9.1 ± 3.7 pg/ml vs. 4.8 ± 2.9 pg/ml; and 9.1 ± 3.7 pg/ml vs. 5.2 ± 3.9 pg/ml, respectively (PD vs. AD, p = 0.01; PD vs. PS, p = 0.03).

CONCLUSIONS

AD and PS can coexist. The role of T helper 17 cells may be more essential than believed.

Physiopathologie de la dermatite atopique et des autres maladies atopiques : une approche globale est-elle possible ?

Atopy is defined by the propensity to develop an exaggerated type-2 inflammatory response to environmental molecules. Clinically, atopy is diagnosed when atopic disease occurs: atopic dermatitis, food allergy, atopic asthma and allergic rhinitis and conjunctivitis. Whereas the classical "atopic march" is increasingly challenged through epidemiological studies, type-2 cellular inflammation is a characteristic shared by the atopic diseases. This inflammation can be innate (non-specific: eosinophils, mast cells, dendritic cells, innate lymphoid cells [ILC]), or adaptive (antigen-specific, involving T cells). Interleukins (IL-)4, 5 and 13 are major actors of type-2 inflammation and are mainly produced by ILC and T cells. The efficacy of treatments targeting these type-2 cytokines highlight the importance of type-2 inflammation in atopic diseases. However, several patients do not respond to type-2 targeting treatments, highlighting the presence of other actors in pathophysiology of atopic diseases: alteration of epithelial barrier, IgE-mediated allergic responses, type-17 inflammation. Thus, the term "endotype" can illustrate this diversity in pathophysiology. Finally, a global approach of atopic diseases, as type-2 inflammatory diseases, is fundamental, but not sufficient. An approach by endotype is advisable, in a personalized medicine perspective. © 2020 Elsevier Masson SAS. All rights reserved.

Atopic dermatitis

Atopic dermatitis (AD) is a common inflammatory skin disease, clinically characterized by recurrent eczematous lesions and intense itching, leading to excoriations and susceptibility to cutaneous infections. Although it is considered a pediatric disorder, mainly starting in infancy, it is also very common in adults. Etiology of AD is complex and multifactorial: interaction between genetic susceptibility and environment, but also cutaneous barrier impairment, change in microbiome composition and innate and adaptive immune dysregulation are the main factors involved in the pathogenesis of the disease. Originally, the disorder was considered mediated by an imbalance towards a T-helper 2 response and excessive IgE production to allergens, but now it is recognized as a lifelong disposition with variable clinical expressivity, where dysfunctions of the epidermal barrier, immune system and microbiome play a central role. AD leads to a substantial psycho-social burden on patients and their relatives and increases the risk of other allergic and non allergic disorders. The real economic impact of AD is difficult to measure due to the broad spectrum of disease severity and the multiple direct and indirect costs, but the overall medical expenses seem to be very high and similar to those of other diseases such as diabetes. Currently, a multiple therapeutic approach is aimed only at improving the skin state, reducing itching and keeping a stable condition. New safety and curative treatments may be developed only after enhancing our understanding on the pathogenesis of AD and the heterogeneity of its clinical manifestations. (www.actabiomedica.it)

Transcriptomes from German shepherd dogs reveal differences in immune activity between atopic dermatitis affected and control skin

Canine atopic dermatitis (CAD) is an inflammatory and pruritic allergic skin disease with both genetic and environmental risk factors described. We performed mRNA sequencing of non-lesional axillary skin biopsies from nine German shepherd dogs. Obtained RNA sequences were mapped to the dog genome (CanFam3.1) and a high-quality skin transcriptome was generated with 23,510 expressed gene transcripts. Differentially expressed genes (DEGs) were defined by comparing three controls to five treated CAD cases. Using a leave-one-out analysis, we identified seven DEGs: five known to encode proteins with functions related to an activated immune system (CD209, CLEC4G, LOC102156842 (lipopolysaccharide-binding protein-like), LOC480601 (regakine-1-like), LOC479668 (haptoglobin-like)), one (OBP) encoding an odorant-binding protein potentially connected to rhinitis, and the last (LOC607095) encoding a novel long non-coding RNA. Furthermore, high mRNA expression of inflammatory genes was found in axillary skin from an untreated mild CAD case compared with healthy skin. In conclusion, we define genes with different expression patterns in CAD case skin helping us understand post-treatment atopic skin. Further studies in larger sample sets are warranted to confirm and to transfer these results into clinical practice.

Diagnosis and management of moderate to severe atopic dermatitis in adolescents. A Consensus by the Italian Society of Dermatology and Venereology (SIDeMaST), the Italian Association of Hospital Dermatologists and Public Health (ADOI), the Italian Association of Hospital and Territorial Allergists and Immunologists (AAIITO), the Italian Society of Allergy, Asthma and Clinical Immunology (SIAAIC), the Italian Society of Pediatric Allergy and Immunology (SIAIP), the Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA), and the Italian Society of Pediatric Dermatology (SIDerP)

Atopic dermatitis (AD) is a chronic inflammatory disease with increasing global incidence, which has a multifactorial pathogenesis and a variable expressivity. Clinical features of AD are different in adults compared to children, but it is well recognized the substantial impact of the disease on patients' quality of life at any age. Indeed, little is known about AD in adolescence, a period of life generally associated with high psychological burden and vulnerability to depression. Guidelines for the management of AD are available for both children and adults but specific guidelines for the diagnosis and treatment of AD in adolescents are lacking. Seven Italian scientific societies of dermatologists, allergists, and pediatric allergists joined in a specific meeting to provide practical guidance for the diagnosis and management of moderate-to-severe adolescent AD suitable for the Italian clinical practice. Through a modified Delphi procedure, consensus was reached by 59 Italian experts in the management of AD on 20 statements covering five areas of interest about adolescent AD, including disease complexity, burden and social impact, diagnosis and definition of severity, current treatments, and new biologic therapies. This paper reports recommendations for the diagnosis and management of AD specifically in adolescents, pointing out some peculiar clinical features and focusing on the choice of medications. Dupilumab, the first biologic approved for the treatment of adolescents with AD, represents a useful treatment option due to its efficacy and reassuring safety profile.

Food Allergy Insights: A Changing Landscape

The panorama of food allergies (FA) has changed profoundly in recent years. In light of recent advances in knowledge of pathogenetic mechanisms and a greater attention to the multifaceted range of possible clinical manifestations, there is a need for a critical review of past classifications. Changes in nutrition, environment and lifestyles around the world are modifying the global FA epidemiology and new FA phenotypes are also emerging. Furthermore, both biotechnological advances in this field and recent personalized therapies have improved the diagnostic and therapeutic approach to FA. Consequently, both the prevention and clinical management of FA are rapidly changing and new therapeutic strategies are emerging, even revolutionizing the current medical practice. Given the significant increase in the prevalence of FA in recent years, the objective of this review is to provide an updated and complete overview of current knowledge in its etiopathogenesis, diagnostics and therapy, useful not only for a better understanding of this frequent and complex pathology but also for practical guidance in its clinical management.

The European TREatment of ATopic eczema (TREAT) Registry Taskforce survey: prescribing practices in Europe for phototherapy and systemic therapy in adult patients with moderate-to-severe atopic eczema

Background

For many years dermatologists have had access to few therapies for patients with moderate‐to‐severe atopic eczema (AE). New promising therapies are entering the market but conventional phototherapies and systemic therapies have more well‐known safety profiles, lower costs and wider availability.

Objectives

To provide insight into current prescribing practices of conventional phototherapy and systemic immunomodulatory therapies for adults with chronic AE, and the factors influencing these prescribing practices, before biologics and other novel therapeutics become routine clinical practice.

Methods

In this exploratory study dermatologists were invited to participate in an online survey via a mailing list of the European Academy of Dermatology and Venereology and national societies. Data were collected on participant characteristics (including clinical practice data), the use of phototherapies and systemic therapies, and factors influencing their use.

Results

From 30 European countries, 238 out of 361 dermatologists willing to participate (65·9%) completed the survey, with 229 meeting the inclusion criteria. For phototherapy (prescribed by 84·7%), most preferred narrowband ultraviolet B as first line (80·9%) and psoralen plus ultraviolet A as second (21·6%). For systemic therapy (prescribed by 95·2%) ciclosporin (54·1%), oral corticosteroids (32·6%) and methotrexate (30·7%) were used first line. Dermatologists relied mostly on personal experience for prescribing phototherapy and systemic therapy. Azathioprine and mycophenolic acid were prescribed by only 135 (59·0%) and 85 (37·1%) participants in total, mostly due to a lack of personal experience.

Conclusions

This study provides insight into prescribing practices for conventional phototherapy and systemic therapy in Europe and shows that off‐label therapies are also preferred as first‐line choice of systemic therapy.

What is already known about this topic?

Varying prescribing practices were found for adult (in the UK) and paediatric (in Northern America and Europe) patients with moderate‐to-severe atopic eczema (AE).

Not much is known about the prescription of phototherapy and (off‐label) systemic therapy for adult patients in Europe.

Although therapies like dupilumab are promising new treatment modalities, better‐known safety profiles, lower costs and better availability are reasons to improve the evidence profile of conventional systemic therapies like ciclosporin.

What does this study add?

Prescribing practices of European dermatologists treating adult patients with moderate‐to-severe AE show diversity.

Most dermatologists prefer narrowband ultraviolet B as first‐line phototherapy, followed by psoralen plus ultraviolet A as second line.

Next to ciclosporin, which is most commonly prescribed, (off‐label) methotrexate and oral corticosteroids are also frequently used as first‐line systemic agents in chronic AE.

Lack of personal experience with azathioprine and mycophenolic acid was the most important reason against their prescription.

What are the clinical implications of the work?

The results from this study might help to improve the experience with, and prescribing of, all available conventional phototherapies and (off‐label) systemic therapies.

Guidelines developers might use these results to develop and implement treatment algorithms.

Linked Comment:Bruin‐Weller. Br J Dermatol 2020; 183:987–988.

Plain language summary available online

Anti-Inflammatory Effects of Bee Venom on Phthalic Anhydride-Induced Atopic Dermatitis

Background: Atopic dermatitis (AD) is a chronic inflammatory condition which can be studied using phthalic anhydride (PA) to induce AD. Anti-inflammatory properties of bee venom (BV) wereinvestigated to determine whether it may be a useful treatment for AD.Methods: AD was induced by applying to pical PA to 8-week-old HR-1 mice (<i>N</i> = 50), then treating with (0.1, 0.25, and 0.5 ?g) or without topical BV. Body weight, ear thickness histology, enzymelinked immune sorbent assay (serum IgE concentrations), Western blot analysis [inducible nitric oxide synthase, cyclooxygenase-2, IκB-α, phospho-IκB-α, c-Jun N-terminal kinase (JNK), phosphoJNK, p38, phospho-p38, extra cellular signal-regulated kinase (ERK), and phospho-ERK], and the pull down assay for immunoblotting (p50), were used to measure inflammatory mediators.Results: PA + BV (0.1, 0.25, and 0.5 μg) significantly decreased ear thickness without altering body weight. IgE concentrations decreased in the PA + BV (0.5 ?g)-treated groups compared with PAtreatment. Tumor necrosis factor-α, interleukin-1β, inducible nitric oxide synthase, cyclooxygenase-2, phospho-IκB-α, phospho-JNK, p38, phospho-p38, and phospho-ERK, all decreased following treatment with PA + BV compared with the PA-treatment alone. p50 was upregulated in the PA + BV-treated groups compared with the PA-treated group. Furthermore, the number of mast cells decreased in the PA + BV-treated groups compared with the PA-treated group. Epidermal thickness was significantly lower in the PA + BV-treated group compared with PA treatment alone.Conclusion: BV maybe a useful anti-inflammatory treatment for AD.

A Review of the Anti-Inflammatory Effects of Rosmarinic Acid on Inflammatory Diseases

Inflammatory diseases are caused by abnormal immune responses and are characterized by an imbalance of inflammatory mediators and cells. In recent years, the anti-inflammatory activity of natural products has attracted wide attention. Rosmarinic acid (RosA) is a water-soluble phenolic compound that is an ester of caffeic acid and 3, 4-dihydroxyphenyl lactic acid. It is discovered in many plants, like those of the Boraginaceae and Lamiaceae families. RosA has a wide range of pharmacological effects, including anti-oxidative, anti-apoptotic, anti-tumorigenic, and anti-inflammatory effects. The anti-inflammatory effects of RosA have been revealed through in vitro and in vivo studies of various inflammatory diseases like arthritis, colitis, and atopic dermatitis. This article mainly describes the preclinical research of RosA on inflammatory diseases and depicts a small amount of clinical research data. The purpose of this review is to discuss the anti-inflammatory effects of RosA in inflammatory diseases and its underlying mechanism.

New Perspectives in Food Allergy

The improvement of the knowledge of the pathophysiological mechanisms underlying the tolerance and sensitization to food antigens has recently led to a radical change in the clinical approach to food allergies. Epidemiological studies show a global increase in the prevalence of food allergy all over the world and manifestations of food allergy appear increasingly frequent also in elderly subjects. Environmental and nutritional changes have partly changed the epidemiology of allergic reactions to foods and new food allergic syndromes have emerged in recent years. The deepening of the study of the intestinal microbiota has highlighted important mechanisms of immunological adaptation of the mucosal immune system to food antigens, leading to a revolution in the concept of immunological tolerance. As a consequence, new prevention models and innovative therapeutic strategies aimed at a personalized approach to the patient affected by food allergy are emerging. This review focuses on these new perspectives and their practical implications in the management of food allergy, providing an updated view of this complex pathology.

An overview of drug discovery efforts for eczema: why is this itch so difficult to scratch?

Introduction: Atopic dermatitis (AD) is a type of allergic/inflammatory dermatitis characterized by itch and an impairment in quality of life.Areas covered: Herein, the authors review drug discovery efforts for AD, highlighting the clinical efficacy of novel drugs, with a particular focus on the relief of pruritus. Topical agents include emollients, topical antihistamines, corticosteroids, calcineurin inhibitors and herbs. Recently, topical phosphodiesterase E4 (PDE4) inhibitors like crisaborole have become available and are efficacious for mild to moderate AD with few side effects. For more severe AD, monoclonal antibodies like dupilumab are considered as efficacious subcutaneous treatment options. In severe and recalcitrant AD, systemic treatment can ameliorate AD symptoms.Expert opinion: Many topical and systemic medications have demonstrated therapeutic benefits for AD. Indeed, randomized trials have shown that topical PDE4 inhibitors and subcutaneous dupilumab are safe and efficacious. Objective tools to evaluate itch and gauge treatment efficacy is important, but current methodology relies primarily on clinical scores. AD is a systemic atopic disease with a lot of complicated psychosocial issues. Suboptimal efficacy is often due to poor compliance and unrealistic expectation of curative treatment, rendering treatment difficult despite the existence of effective medications.

Spontaneous atopic dermatitis in mice with a defective skin barrier is independent of ILC2 and mediated by IL-1β

BACKGROUND

Atopic dermatitis (AD) is one of the most common skin diseases with a multifactorial etiology. Mutations leading to loss of skin barrier function are associated with the development of AD with group 2 innate lymphoid cells (ILC2) promoting acute skin inflammation. Filaggrin-mutant (Flgft/ft ) mice develop spontaneous skin inflammation accompanied by an increase in skin ILC2 numbers, IL-1β production, and other cytokines recapitulating human AD. Here, we investigated the role of ILC2, effector cytokines, inflammasome activation, and mast cell function on the development of chronic AD-like inflammation in mice.

METHODS

Mice with a frameshift mutation in the filaggrin gene develop spontaneous dermatitis. Flgft/ft mice were crossed to cell- or cytokine-deficient mouse strains, or bred under germ-free conditions. Skin inflammation was scored, and microbiome composition was analyzed. Skin protein expression was measured by multiplex immunoassay. Infiltrating cells were analyzed by flow cytometry.

RESULTS

Wild-type and Flgft/ft mice significantly differ in their microbiome composition. Furthermore, mutant mice do not develop skin inflammation under germ-free conditions. ILC2 deficiency did not ameliorate chronic dermatitis in Flgft/ft mice, which was also independent of IL-4, IL-5, IL-9, IL-13, IL-17A, and IL-22. Inflammation was independent of NLRP3 inflammasome activation but required IL-1β and IL-1R1-signaling. Mechanistically, IL-1β promoted hyperactivation of IL-1R1-expressing mast cells. Treatment with anti-IL-1β-antibody alleviated dermatitis exacerbation, while antibiotic intervention ameliorated dermatitis in neonatal mice but not in adults with established inflammation.

CONCLUSIONS

In summary, we identified a critical role for the microbiome and IL-1β mediating chronic inflammation in mice with an impaired skin barrier.

Understanding the immune landscape in atopic dermatitis: The era of biologics and emerging therapeutic approaches

Atopic dermatitis (AD) is a chronic, systemic, inflammatory disease that affects the skin and is characterized by persistent itch and marked redness. AD is associated with an increased risk of skin infections and a reduced quality of life. Most AD treatment options to date were not designed to selectively target disease-causing pathways that have been established for this indication. Topical therapies have limited efficacy in moderate-to-severe disease, and systemic agents such as corticosteroids and immunosuppressants present with tolerability issues. Advances in the understanding of AD pathobiology have made possible a new generation of more disease-specific AD therapies. AD is characterized by the inappropriate activation of type 2 T helper (Th2) cells and type 2 innate lymphoid (ILC2) cells, with a predominant increase in type 2 cytokines in the skin, including interleukin (IL)-13 and IL-4. Both cytokines are implicated in tissue inflammation and epidermal barrier dysfunction, and monoclonal antibodies targeting each of these interleukins or their receptors are in clinical development in AD. In March 2017, dupilumab, a human anti-IL-4Rα antibody, became the first biologic to receive approval in the United States for the treatment of moderate-to-severe AD. The anti-IL-13 monoclonal antibodies lebrikizumab and tralokinumab, which bind different IL-13 epitopes with potentially different effects, are currently in advanced-stage trials. Here, we briefly review the underlying pathobiology of AD, the scientific basis for current AD targets, and summarize current clinical studies of these agents, including new research to develop both predictive and response biomarkers to further advance AD therapy in the era of precision medicine.

Recent Advances in Allergy Research Using Humanized Mice

The prevalence rates of allergic diseases are increasing worldwide, particularly in industrial countries. To date, many mouse models have been generated for allergy research; studies conducted using these models have suggested the importance of cross-talk between immune cells and tissue-resident non-immune cells in the onset of allergic diseases. However, there are several differences between the immune systems of rodents and humans, and human studies are limited. Thus, mice reconstituted with human immune cells are a novel tool for the preclinical evaluation of the efficacy and safety of developing drugs. Genetic technologies for generating humanized mice have improved markedly in recent years. In this review, we will discuss recent progress in allergy research using humanized mice and introduce our recent humanized mouse model of airway inflammation in human immune cells.

More from the Pipeline of Clinical Research on SELECTED SYSTEMIC THERAPIES FOR ATOPIC DERMATITIS

Many systemic therapies are under development for atopic dermatitis, many of which are injectable monoclonal antibodies that inhibit specific pathways involved in the pathogenesis of the disease. Most are currently under development, however, there are preliminary studies with subcutaneous omalizumab (IgE-directed therapy), and oral apremilast (phosphodiesterase-4 [PDE-4] inhibition. Further studies are needed with these agents. This article discusses various agents that address several potential therapeutic approaches, including IgE-directed therapy, anti-IL-31, anti-IL-5, anti-IL-22, PDE-4 inhibition, and thymic stromal lymphopoietin (TSLP)-directed therapy.

[Personalized medicine in allergology]

BACKGROUND

Personalized medicine offers new perspectives for diagnostic measurements and medical treatment, but also puts greater demands on the physician.

OBJECTIVES

Developments, potentials and potential pitfalls of personalized medicine in allergology.

METHODS

Overview, evaluation and discussion of the current state of science on the basis of selected examples.

RESULTS

Allergic diseases like allergic rhinitis, atopic eczema or anaphylaxis can be classified into various clinical phenotypes, which are based on different immunological endotypes. These can be captured and categorized by a wide variety of omics technologies. The identification of endotype specific biomarkers holds promising opportunities of more precise diagnostics, the implementation of novel targeted therapies or the development of optimized preventive strategies. However, individualized analysis and assessment of the significance of the measurements represent special challenges.

CONCLUSIONS

Findings of the complex omics technologies need to be evaluated by comprehensive prospective studies in order to validate their clinical relevance and suitability for personalized medicine in allergology.

Emerging therapies for atopic dermatitis: JAK inhibitors

The Janus kinase-signal transducer and activator of transcription pathway is a conserved master regulator of immunity and myeloproliferation. Advanced understanding of this pathway has led to development of targeted inhibitors of Janus kinases (Jakinibs). As a class, JAK inhibitors effectively treat a multitude of hematologic and inflammatory diseases. Given such success, use of JAK inhibitors for mitigation of atopic dermatitis is under active investigation. Herein, we review the evolving data on the safety and efficacy of JAK inhibitors in treatment of atopic dermatitis. Although it is still early in the study of JAK inhibitors for atopic dermatitis, evidence identifies JAK inhibitors as effective alternatives to conventional therapies. Nonetheless, multiple large safety and efficacy trials are needed before widespread use of JAK inhibitors can be advocated for atopic dermatitis.