Atopic dermatitis endotypes and implications for targeted therapeutics

Pooled Analysis of Baricitinib Tolerability in Patients With Atopic Dermatitis in Relation to Acne, Headache, and Gastrointestinal Events From 8 Clinical Trials

Background: Tolerability issues including acne, nausea, and headache have been reported with Janus kinase (JAK) inhibitors for moderate-to-severe atopic dermatitis (AD). Objectives: To report outcomes of tolerability adverse events (AEs) for baricitinib, a JAK1/JAK2 inhibitor, in patients with moderate-to-severe AD. Methods: Acne, headache, and gastrointestinal AEs are reported from placebo-controlled and long-term extensions of pooled data in the baricitinib AD clinical trial program. Proportions of patients with AEs, incidence rates (IRs)/100 patient-years at risk, and median time to onset/duration of AEs were calculated. Results: In 2531 patients treated with baricitinib, most AEs were mild to moderate in severity. Headache was the most common AE of tolerability (median of 14-26 days after first dose of baricitinib, lasting ≤3 days). IRs of acne were <5 in any group lasting up to a median of 90 days with no severe AEs. Diarrhea was the most common gastrointestinal AE, lasting a median of ≤7 days. There were few study drug interruptions (n = 6) and permanent discontinuations (n = 5) for tolerability AEs. Conclusions: For the AEs of tolerability analyzed, baricitinib appears to be well tolerated. Overall, the frequency of these AEs in patients being treated for moderate-to-severe AD was low with few leading to study drug interruption or permanent discontinuation. Clinical Trial Registration number: NCT02576938; NCT03334396; NCT03334422; NCT03428100; NCT03435081; NCT03733301; NCT03334435; NCT03559270.

A homogeneous Lonicera japonica polysaccharide alleviates atopic dermatitis by promoting Nrf2 activation and NLRP3 inflammasome degradation via p62

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicera japonica Thunb. is a traditional medicinal herb with a long history owing to its widespread use in Asia for the treatment of several inflammatory diseases including allergic dermatitis; however, its active components and mechanism of action have not been fully elucidated.

AIM OF THE STUDY

In this study, a homogeneous polysaccharide with strong anti-inflammatory effects was extracted from the traditional Chinese medicine Lonicera japonica. The mechanism by which the polysaccharide WLJP-025p regulates p62 to activate Nrf2, promote NLRP3 inflammasome degradation, and improve AD was investigated.

MATERIALS AND METHODS

An AD model was established using DNCB, and saline was used as a control. The WLJP-L and WLJP-H groups were administered 30 and 60 mg/kg WLJP-025p during the model challenge period, respectively. The therapeutic effect of WLJP-025p was evaluated by determining the skin thickness, performing HE and toluidine blue staining, detecting TSLP via IHC, and determining serum IgE and IL-17 levels. Th17 differentiation was detected using flow cytometry. IF and WB were performed to evaluate the expression levels of c-Fos, p-p65, NLRP3 inflammatory bodies, autophagy pathway, ubiquitination, and Nrf2 proteins.

RESULTS

WLJP-025p significantly inhibited DNCB-induced skin hyperplasia and pathological abnormalities and increased TSLP levels in mice. The differentiation of Th17 in the spleen, IL-17 release, p-c-Fos, p-p65 protein expression, and NLRP3 inflammasome activation in the skin tissues were reduced. Furthermore, p62 expression, p62 Ser403 phosphorylation, and ubiquitinated proteins were increased.

CONCLUSIONS

WLJP-025p improved AD in mice by upregulating p62 to activate Nrf2 and promote the ubiquitination and degradation of NLRP3.

Calcitriol, an Active Form of Vitamin D3, Mitigates Skin Barrier Dysfunction in Atopic Dermatitis NC/Nga Mice

Atopic dermatitis and psoriasis are prevalent chronic inflammatory skin diseases that are characterized by dysfunctional skin barriers and substantially impact patients' quality of life. Vitamin D3 regulates immune responses and keratinocyte differentiation and improves psoriasis symptoms; however, its effects on atopic dermatitis remain unclear. Here, we investigated the effects of calcitriol, an active form of vitamin D3, on an NC/Nga mouse model of atopic dermatitis. We observed that the topical application of calcitriol decreased the dermatitis scores and epidermal thickness of NC/Nga mice with atopic dermatitis compared to untreated mice. In addition, both stratum corneum barrier function as assessed by the measurement of transepidermal water loss and tight junction barrier function as evaluated by biotin tracer permeability assay were improved following calcitriol treatment. Moreover, calcitriol treatment reversed the decrease in the expression of skin barrier-related proteins and decreased the expression of inflammatory cytokines such as interleukin (IL)-13 and IL-33 in mice with atopic dermatitis. These findings suggest that the topical application of calcitriol might improve the symptoms of atopic dermatitis by repairing the dysfunctional epidermal and tight junction barriers. Our results suggest that calcitriol might be a viable therapeutic agent for the treatment of atopic dermatitis in addition to psoriasis.

Increased Risk of Dementia in Patients with Atopic Dermatitis: A Nationwide Population-Based Cohort Study

Atopic dermatitis (AD) is a chronic inflammatory skin disorder with bimodal incidence peaks in early childhood and middle-aged and older adults. Few studies have focused on the risk of dementia in AD. The aims of this study were to analyse the incidence, and risk factors for dementia in patients with AD. This nationwide population-based retrospective cohort study enrolled 38,391 adults ≥ 40 years of age with AD and 2,643,602 controls without AD from the Korean National Health Insurance System (NHIS) database from 2009 to 2016. The cumulative incidence probability of all-cause dementia, Alzheimer's disease, or vascular dementia at 8 years was 50, 39, and 7 per 1,000 person-years in patients with AD, respectively. The adjusted risks of all-cause dementia (hazard ratio (HR), 1.072; 95% confidence interval (95% CI) 1.026-1.120), and Alzheimer's disease (HR 1.051; 95% CI 1.000-1.104) were increased in patients with AD. The effect of AD on the development of all-cause dementia and Alzheimer's dementia varied according to age and diabetes mellitus (all p for interaction, < 0.05). The risks of all-cause dementia and Alzheimer's disease were increased in patients with AD. Management of modifiable risk factors is important for preventing dementia in patients with AD.

How to Understand Personalized Medicine in Atopic Dermatitis Nowadays?

Atopic dermatitis (AD) is a heterogeneous disease in terms of its phenotypical, barrier, and immunological presentation. Emerging therapies are undoubtedly contributing to a new chapter in the treatment of AD, bringing an excellent possibility of individualization, and thereby creating a tailored approach. The two most promising substance groups are biological drugs (dupilumab, tralokinumab, lebrikizumab, nemolizumab) and Janus kinase inhibitors (JAKis) (baricitinib, upadacitinib, and abrocitinib). The vision that certain well-defined phenotypes and endotypes, as well as personal preferences, may guide the future treatment of AD is both tempting and appealing, but not yet reality. The accessibility of new drugs such as biologics and small molecules has opened up the discussion regarding personalized medicine, referring to the complex nature of AD as well as the experiences from clinical trials and real-world evidence. We have now reached the point of creating new strategies and AD treatment goals by increasing the amount of new information concerning the efficacy and safety of new drugs. This article has reviewed the novel treatment options for AD in the light of the heterogeneity of this disease and proposes a broader vision on the strategy of personalized treatment of AD.

The hidden sentinel of the skin: An overview on the role of interleukin-13 in atopic dermatitis

Recent evidence suggests that interleukin (IL)-13 is a crucial cytokine involved in the pathogenesis of atopic dermatitis (AD). It is a central driver of type-2 T-helper inflammation and is overexpressed in lesional skin of AD patients. Upon release in peripheral skin, IL-13 activates its receptors, recruits inflammatory cells, and modifies the skin microbiome. IL-13 also reduces the expression of epidermal barrier proteins and activates sensory nerve mediating the itch transmission signal. Novel therapeutics that target IL-13 seem to be efficacious and safe for the treatment of patients with moderate-to-severe AD. The aim of our manuscript is to review the role that IL-13 plays in AD immunopathogenesis.

Overview of Atopic Dermatitis in Different Ethnic Groups

Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a high prevalence worldwide, including countries from Asia, Africa, and Latin America, and in different ethnic groups. In recent years, more attention has been placed on the heterogeneity of AD associated with multiple factors, including a patient's ethnic background, resulting in an increasing body of clinical, genetic, epidemiologic, and immune-phenotypic evidence that delineates differences in AD among racial groups. Filaggrin (FLG) mutations, the strongest genetic risk factor for the development of AD, are detected in up to 50% of European and 27% of Asian AD patients, but very rarely in Africans. Th2 hyperactivation is a common attribute of all ethnic groups, though the Asian endotype of AD is also characterized by an increased Th17-mediated signal, whereas African Americans show a strong Th2/Th22 signature and an absence of Th1/Th17 skewing. In addition, the ethnic heterogeneity of AD may hold important therapeutic implications as a patient's genetic predisposition may affect treatment response and, thereby, a tailored strategy that better targets the dominant immunologic pathways in each ethnic subgroup may be envisaged. Nevertheless, white patients with AD represent the largest ethnicity enrolled and tested in clinical trials and the most treated in a real-world setting, limiting investigations about safety and efficacy across different ethnicities. The purpose of this review is to describe the heterogeneity in the pathophysiology of AD across ethnicities and its potential therapeutic implications.

Skin microbiome and its association with host cofactors in determining atopic dermatitis severity

BACKGROUND

Atopic dermatitis (AD) is a heterogeneous, chronic inflammatory skin disease linked to skin microbiome dysbiosis with reduced bacterial diversity and elevated relative abundance of Staphylococcus aureus (S. aureus).

OBJECTIVES

We aimed to characterize the yet incompletely understood association between the skin microbiome and patients' demographic and clinical cofactors in relation to AD severity.

METHODS

The skin microbiome in 48 adult moderate-to-severe AD patients was investigated using next-generation deep sequencing (16S rRNA gene, V1-V3 region) followed by denoising (DADA2) to obtain amplicon sequence variant (ASV) composition.

RESULTS

In lesional skin, AD severity was associated with S. aureus relative abundance (r_S  = 0.53, p < 0.001) and slightly better with the microbiome diversity measure Evenness (r_S  = -0.58, p < 0.001), but not with Richness. Multiple regression confirmed the association of AD severity with microbiome diversity, including Shannon (in lesional skin, p < 0.001), Evenness (in non-lesional skin, p = 0.015) or S. aureus relative abundance (p < 0.012), and with patient's IgE levels (p < 0.001), race (p < 0.032), age (p < 0.034) and sex (p = 0.012). The lesional model explained 62% of the variation in AD severity, and the non-lesional model 50% of the variation.

CONCLUSIONS

Our results specify the frequently reported "reduced diversity" of the AD-related skin microbiome to reduced Evenness, which was in turn mainly driven by S. aureus relative abundance, rather than to a reduced microbiome Richness. Finding associations between AD severity, the skin microbiome and patient's cofactors is a key aspect in developing new personalized AD treatments, particularly those targeting the AD microbiome.

Crisaborole efficacy in murine models of skin inflammation and Staphylococcus aureus infection

Phosphodiesterase 4 (PDE4) is highly expressed in keratinocytes and immune cells and promotes pro-inflammatory responses upon activation. The activity of PDE4 has been attributed to various inflammatory conditions, leading to the development and approval of PDE4 inhibitors as host-directed therapeutics in humans. For example, the topical PDE4 inhibitor, crisaborole, is approved for the treatment of mild-to-moderate atopic dermatitis and has shown efficacy in patients with psoriasis. However, the role of crisaborole in regulating the immunopathogenesis of inflammatory skin diseases and infection is not entirely known. Therefore, we evaluated the effects of crisaborole in multiple mouse models, including psoriasis-like dermatitis, AD-like skin inflammation with and without filaggrin mutations, and Staphylococcus aureus skin infection. We discovered that crisaborole dampens myeloid cells and itch in the skin during psoriasis-like dermatitis. Furthermore, crisaborole was effective in reducing skin inflammation in the context of filaggrin deficiency. Importantly, crisaborole reduced S. aureus skin colonization during AD-like skin inflammation. However, crisaborole was not efficacious in treating S. aureus skin infections, even as adjunctive therapy to antibiotics. Taken together, we found that crisaborole reduced itch during psoriasis-like dermatitis and decreased S. aureus skin colonization upon AD-like skin inflammation, which act as additional mechanisms by which crisaborole dampens the immunopathogenesis in mouse models of inflammatory skin diseases. Further examination is warranted to translate these preclinical findings to human disease.

The translational revolution in atopic dermatitis: the paradigm shift from pathogenesis to treatment

Atopic dermatitis (AD) is the most common inflammatory skin disease, and it is considered a complex and heterogeneous condition. Different phenotypes of AD, defined according to the patient age at onset, race, and ethnic background; disease duration; and other disease characteristics, have been recently described, underlying the need for a personalized treatment approach. Recent advancements in understanding AD pathogenesis resulted in a real translational revolution and led to the exponential expansion of the therapeutic pipeline. The study of biomarkers in clinical studies of emerging treatments is helping clarify the role of each cytokine and immune pathway in AD and will allow addressing the unique immune fingerprints of each AD subset. Personalized medicine will be the ultimate goal of this targeted translational research. In this review, we discuss the changes in the concepts of both the pathogenesis of and treatment approach to AD, highlight the scientific rationale behind each targeted treatment and report the most recent clinical efficacy data.

Is Dupilumab as Effective in Intrinsic Atopic Dermatitis as It Is in Extrinsic Atopic Dermatitis?

Atopic dermatitis (AD) can be subclassified into the more frequent extrinsic type (EAD), with elevated serum IgE levels and frequent association with other atopic conditions, and the less frequent intrinsic type (IAD), with normal IgE levels and no history of atopy. This retrospective study has the objective to compare the efficacy of dupilumab therapy in patients with IAD versus EAD in a real-life setting. We studied a group of 360 patients treated with dupilumab for moderate-to-severe AD of whom 49 had IAD (IgE < 200 kU/L and no history of other atopic conditions) and 311 had EAD (IgE ≥ 200 kU/L and/or history of atopy). There were no statistically significant differences in the achievement of EASI75 between IAD and EAD patients either at 16, 32, or 48 weeks (61% vs. 50%; 66% vs. 60%; and 53% vs. 65%, respectively). Similarly, there were no statistically significant differences in the achievement of EASI90 or the reduction in NRSpp, NRSsd, and DLQI at each timepoint. Additionally, mean absolute eosinophils and IgE values were significantly higher in the EAD group at all timepoints. This study confirms that dupilumab, targeting the Th2 pathway, which is known to be overexpressed in all AD phenotypes, appears to be equally effective in the two populations regardless of IgE levels.

Atopic dermatitis complicated by recurrent eczema herpeticum is characterized by multiple, concurrent epidermal inflammatory endotypes

BACKGROUND

A subgroup of atopic dermatitis (AD) patients suffer from recurrent, disseminated herpes simplex virus (HSV) skin infections, termed eczema herpeticum (EH), which can be life-threatening and contribute to AD morbidity. The pathobiology underlying ADEH is unknown.

OBJECTIVE

To determine transcriptional mechanisms of skin and immune system pathobiology that underlie ADEH disease.

METHODS

We performed whole transcriptome RNA-sequencing of non-lesional skin samples (epidermis, dermis) of AD patients with (ADEH + , n=15) and without (ADEH - , n=13) recurrent EH history, and healthy controls (HC, n=15). We also performed RNA-sequencing on plasmacytoid dendritic cells (pDCs) collected from these participants and infected in vitro with HSV-1. Differential expression, gene set enrichment, and endotyping analyses were performed.

RESULTS

ADEH + disease was characterized by dysregulation in skin gene expression, which was limited in dermis (differentially expressed genes [DEGs]=14) and widespread in epidermis (DEGs=129). ADEH + -upregulated epidermal DEGs were enriched in type 2 cytokine (T2) ( IL4R, CCL22, CRLF2, IL7R ), interferon ( CXCL10, ICAM1, IFI44 , and IRF7) , and IL-36γ ( IL36G ) inflammatory pathway genes. At a person-level, all ADEH + participants exhibited T2 and interferon endotypes and 87% were IL36G-high. In contrast, these endotypes were more variably expressed among ADEH - participants. ADEH + patient skin also exhibited dysregulation in epidermal differentiation complex (EDC) genes within the LCE, S100 , and SPRR families, which are involved in skin barrier function, inflammation, and antimicrobial activities. pDC transcriptional responses to HSV-1 infection were not altered by ADEH status.

CONCLUSIONS

ADEH + pathobiology is characterized by a unique, multi-faceted epidermal inflammation that accompanies dysregulation in the expression of EDC genes.

Key Messages

AD patients with a history of recurrent EH exhibit molecular skin pathobiology that is similar in form, but more severe in degree, than in AD patients without this complication. Non-lesional skin of ADEH + patients concurrently exhibits excessive type 2 cytokine, interferon, and IL-36γ-driven epidermal inflammation. Expression of these inflammatory skin endotypes among ADEH + patients is associated with dysregulation in expression of epidermal differentiation complex genes involved in barrier function, inflammation, and antimicrobial activity.

Capsule Summary

AD patients with a history of recurrent disseminated HSV-1 skin infections form a unique molecular skin endotype group that concurrently exhibits type 2 cytokine, interferon, and IL-36γ-driven skin inflammation, accompanied by dysregulation in expression of epidermal differentiation complex genes involved in barrier function, inflammation, and antimicrobial activity.

Recent insights into comorbidities in atopic dermatitis

INTRODUCTION

The relationship between atopic dermatitis and atopic diseases such as food allergies, asthma, and allergic rhinitis in terms of co-occurrence, underlying mechanisms, and therapy is well documented. There is increasing evidence that atopic dermatitis is associated with non-atopic comorbidities such as cardiac, autoimmune, and neuropsychological comorbidities, as well as cutaneous and extracutaneous infections, establishing atopic dermatitis as a systemic disease.

AREAS COVERED

The authors reviewed evidence on atopic and non-atopic comorbidities of atopic dermatitis. A literature search was conducted in PubMed for peer-reviewed articles published until October 2022.

EXPERT OPINION

Atopic and non-atopic diseases coexist with atopic dermatitis more often than would be expected by chance. The effect of biologics and small molecules on atopic and non-atopic comorbidities may contribute to a better understanding of the relationship between atopic dermatitis and its comorbidities. Their relationship needs to be explored further to dismantle the underlying mechanism and move toward an atopic dermatitis endotype-based therapeutic approach.

Baseline skin cytokine profiles determined by RNA in situ hybridization correlate with response to dupilumab in patients with eczematous dermatitis

BACKGROUND

Dupilumab has revolutionized the treatment of atopic dermatitis. However, not all patients respond optimally, and this may relate to underlying molecular heterogeneity. Nevertheless, clinically useful and accessible methods to assess such heterogeneity have not been developed.

OBJECTIVE

We assessed whether cytokine staining and/or histologic features correlate with clinical response to dupilumab in patients with eczematous dermatitis.

METHODS

We retrospectively analyzed biopsies from 61 patients with eczematous dermatitis treated with dupilumab (90.2% met Hanifin-Rajka criteria for atopic dermatitis). RNA in situ hybridization was used to measure markers of type 2 (interleukin [IL]4, IL13), type 1 (interferon gamma) and type 3 (IL17A, IL17F, IL22) inflammation. Histologic features were also assessed. Patterns were compared among complete (n = 16), partial (n = 37), and nonresponders (n = 8) to dupilumab.

RESULTS

We found that increased IL13 expression was associated with optimal response to dupilumab. In contrast, nonresponders tended to express less IL13 and relatively greater levels of type 1 and 3 cytokines. In addition, certain histologic features tended to correlate with improved response to dupilumab.

LIMITATIONS

Retrospective approach and small size of the nonresponder group.

CONCLUSION

Cytokine RNA in situ hybridization may aid in treatment selection for eczematous disorders. Moreover, personalization of treatment selection for inflammatory skin diseases may be possible.

Blockage of the IL-31 Pathway as a Potential Target Therapy for Atopic Dermatitis

Atopic dermatitis (AD), a pruritic, inflammatory chronic disease with multifactorial pathogenesis, has been a therapeutic challenge. Novel target treatments aim to reduce not only the immunologic dysfunction and microbiome dysbiosis but also the recovery of the damaged skin barrier. The current review focuses on the interleukin 31 (IL-31) pathway and AD and offers an overview of the current clinical studies with monoclonal antibodies blocking this cascade. Pruritus, the key symptom of AD, has substantial participation of the IL-31 complex and activation of relevant signaling pathways. Epidermal keratinocytes, inflammatory cells, and cutaneous peripheral nerves express the interleukin-31 receptor α-chain (IL-31RA), upregulated by Staphylococcus aureus toxins or Th2 cytokines involved in AD. Nemolizumab is a humanized monoclonal antibody that antagonizes IL-31RA, inhibiting the IL-31 cascade and therefore contributing to reducing the pruritus and inflammation and recovering the damaged skin barrier in AD patients. Phases 2 and 3 clinical trials with nemolizumab in AD show a suitable safety profile, with a fast, efficient, and sustained reduction of pruritus and severity scores, especially when associated with topical treatment. Deciphering the full interplay of the IL-31 pathway and AD may expand the potential of nemolizumab as a targeted therapy for AD and other pruritic conditions.

Topical Administration of Crisaborole in Mild to Moderate Atopic Dermatitis: A Systematic Review and Meta-Analysis

Background. Crisaborole has been considered a promising alternative for topical treatment of atopic dermatitis (AD), mainly supported by AD-301 and AD-302. However, critical insights into these two studies have previously been proposed. Objective. To make a comprehensive assessment of the application of crisaborole in mild to moderate AD. Methods. A systematic review and meta-analysis were conducted, in which only randomized controlled trials comparing the application of crisaborole twice daily to vehicle or other active treatment in patients with mild to moderate AD were included. The selection of outcomes was based on the recommendation of the HOME initiative. Patient-reported symptoms, clinician-reported signs, health-related quality of life, and the safety of crisaborole were all assessed using appropriate measurement instruments. Results. Eight RCTs with 2266 patients were included in the pooled analysis. Compared to those treated with vehicle, patients on crisaborole experienced a greater improvement in NRS (MD −0.70; 95% CI −0.94 to −0.47), POEM (MD −3.50; 95% CI −4.34 to −2.66), EASI (MD −14.49%; 95% CI −18.24% to −10.73%), ISGA (RR 1.45; 95% CI 1.28 to 1.63), DLQI (MD −1.54; 95% CI −2.17 to −0.92), and DFI (MD −1.16; 95% CI −1.72 to −0.59) during the 4-week treatment. More patients achieved EASI 75 (RR 1.71; 95% CI 1.43 to 2.04) with crisaborole administration. There was no significant difference between two interventions in the incidence of AEs (RR 1.12; 95% CI 0.98 to 1.29), SAEs (RR 1.89; 95% CI 0.47 to 7.60), or AE-related withdrawal (RR 0.87; 95% CI 0.47 to 1.60). One RCT also made comparison between crisaborole and pimecrolimus, suggesting that no significant difference was detected in the improvement of EASI or NRS at most time points. Conclusion. High-quality evidence was provided to demonstrate that the short-term application of crisaborole is safe and efficacious for the treatment of mild to moderate AD. The practical efficacy of crisaborole is similar to that of pimecrolimus.

Pimecrolimus for the Treatment of Atopic Dermatitis in Infants: An Asian Perspective

Atopic dermatitis (AD) is a common chronic, multisystem inflammatory skin disease in pediatric patients. There has been an increase in the incidence of AD in the pediatric population of the Asia-Pacific region. Studies have shown that genetic, epigenetic, environmental and cultural factors may lead to differences in the clinical manifestation and prevalence of AD between races. Early treatment of AD is necessary to prevent the atopic march leading to comorbidities such as asthma and allergic rhinitis. Topical corticosteroids (TCS) are used as first-line therapy for the treatment of AD, but their long-term usage poses a risk to the patient's health. Pimecrolimus (1%) is a topical calcineurin inhibitor (TCI) that is indicated for the treatment of mild to moderate AD. Pimecrolimus has no apparent increase in adverse events compared to TCS, and it causes less of a burning sensation than tacrolimus. The safety and efficacy of pimecrolimus has been established through various clinical trials; yet, in many Asian countries, the use of pimecrolimus in infants is still restricted due to safety concerns. Based on the available evidence, the expert panel recommends pimecrolimus in infants between 3 months and 2 years of age in the Asian population.

Oral Janus kinase inhibitors for atopic dermatitis

Atopic dermatitis (AD) is one of the most common inflammatory skin conditions. The pathogenesis of AD involves skin barrier disruption and immune activation of T-helper (T_H)2 and T_H22 and varying degrees of T_H1 and T_H17 activation in various patient subtypes. Although AD is mainly driven by T_H2, the molecular and clinical heterogeneity of AD underscores the need for more efficacious treatments that target multiple immune axes. Janus kinase (JAK) inhibitors are novel therapeutics that broadly block many AD-related proinflammatory cytokines (interleukin [IL]-4, IL-5, IL-13, IL-31, thymic stromal lymphopoietin, interferon gamma, IL-12, IL-23, IL-17) across different immune pathways. Oral JAK inhibitors have been found to be efficacious in AD, with 2 (abrocitinib and upadacitinib) recently gaining US Food and Drug Administration approval and several others under investigation in clinical trials with promising results. These systemic agents have surpassed conventional thresholds of treatment response, with many patients achieving complete or almost complete skin clearance, and provide a fast-acting alternative therapy for patients who are not responsive to biologics or other conventional therapies. However, systemic JAK inhibitors come with health concerns, requiring additional long-term clinical trials to characterize their safety profile in patients with AD. This review summarizes the current literature on the safety and efficacy of oral JAK inhibitors in AD and discusses future directions for research.

Efficacy and Safety of Lebrikizumab in Combination With Topical Corticosteroids in Adolescents and Adults With Moderate-to-Severe Atopic Dermatitis: A Randomized Clinical Trial (ADhere)

Importance

Lebrikizumab (LEB), a high-affinity monoclonal antibody targeting interleukin (IL)-13, demonstrated efficacy and safety in patients with moderate-to-severe atopic dermatitis (AD) during 16 weeks of monotherapy in a phase 2b trial, and two 52-week phase 3 trials.

Objective

To evaluate efficacy and safety of LEB combined with low- to mid-potency topical corticosteroids (TCS) in patients with moderate-to-severe AD.

Design, Setting, and Participants

The ADhere trial was a 16-week randomized, double-blinded, placebo (PBO)-controlled, multicenter, phase 3 clinical trial conducted from February 3, 2020, to September 16, 2021. The study was conducted at 54 outpatient sites across Germany, Poland, Canada, and the US and included adolescent (aged ≥12 to <18 years weighing ≥40 kg) and adult patients with moderate-to-severe AD. The treatment allocation ratio was 2:1 (LEB:PBO).

Interventions

Overall, 211 patients were randomized to subcutaneous LEB (loading dose of 500 mg at baseline and week 2, followed by 250 mg every 2 weeks [Q2W] thereafter) or PBO Q2W in combination with TCS for 16 weeks.

Main Outcomes and Measures

Efficacy analyses at week 16 included proportions of patients achieving Investigator's Global Assessment score of 0 or 1 (IGA [0,1]) with 2 or more points improvement from baseline, and 75% improvement in the Eczema Area and Severity Index (EASI-75). Key secondary end points included evaluation of itch, itch interference on sleep, and quality of life. Safety assessments included monitoring adverse events (AEs).

Results

The mean (SD) age of patients was 37.2 (19.3) years, 103 (48.8%) patients were women, 31 (14.7%) patients were Asian, and 28 (13.3%) patients were Black/African American. At week 16, IGA (0,1) was achieved by 145 (41.2%) patients in the LEB+TCS group vs 66 (22.1%) receiving PBO+TCS (P = .01); corresponding proportions of patients achieving EASI-75 were 69.5% vs 42.2% (P < .001). The LEB+TCS group showed statistically significant improvements in all key secondary end points. Most treatment-emergent adverse events (TEAEs) were nonserious, mild or moderate in severity, and did not lead to study discontinuation. The TEAEs frequently reported in the LEB+TCS group included conjunctivitis (7 [4.8%]), headache (7 [4.8%]), hypertension (4 [2.8%]), injection site reactions (4 [2.8%]), and herpes infection (5 [3.4%]) vs 1.5% or less patient-reported frequencies in the PBO+TCS group. Similar frequencies of patient-reported serious AEs following LEB+TCS (n = 2, 1.4%) and PBO+TCS (n = 1, 1.5%).

Conclusions and Relevance

In this randomized phase 3 clinical trial, LEB+TCS was associated with improved outcomes in adolescents and adults with moderate-to-severe AD compared with TCS alone, and safety was consistent with previously reported AD trials.

Trial Registration

ClinicalTrials.gov Identifier: NCT04250337.

Modern Interventions for Pediatric Atopic Dermatitis: An Updated Pharmacologic Approach

Pediatric atopic dermatitis (AD) has historically challenged dermatologists given the variable response of patients to treatment and limited available therapeutic options, often with significant potential side effects. Over the last decade, targeted treatments including dupilumab and Janus kinase (JAK) inhibitors have emerged as significant treatment advances. An updated therapeutic approach for incorporating these new practice-changing medications can help clinicians manage these challenging patients. In this review, we discuss emerging topical and systemic (oral and injectable) treatments in pediatric AD, including topical PDE4 inhibitors and tapinarof, oral JAK inhibitors, and injected biologics including IL-4Rα inhibitor dupilumab, IL-13 inhibitor tralokinumab, IL-13Rα inhibitor lebrikizumab, IL-31Rα inhibitor nemolizumab, and IL-5Rα inhibitor benralizumab. We also review experimental agents in early clinical trials, such as targeted microbiome transplant lotions/antimicrobials, which may gain relevance in AD treatment. Finally, we propose a therapeutic approach for pediatric AD that incorporates newer therapies including dupilumab and JAK inhibitors, recognizing that these agents may not be universally available or approved. Further trials that include pediatric patients, especially head-to-head studies among therapeutic classes, are needed to clarify the role of emerging treatments.

Periostin activates distinct modules of inflammation and itching downstream of the type 2 inflammation pathway

Atopic dermatitis (AD) is a chronic relapsing skin disease accompanied by recurrent itching. Although type 2 inflammation is dominant in allergic skin inflammation, it is not fully understood how non-type 2 inflammation co-exists with type 2 inflammation or how type 2 inflammation causes itching. We have recently established the FADS mouse, a mouse model of AD. In FADS mice, either genetic disruption or pharmacological inhibition of periostin, a downstream molecule of type 2 inflammation, inhibits NF-κB activation in keratinocytes, leading to downregulating eczema, epidermal hyperplasia, and infiltration of neutrophils, without regulating the enhanced type 2 inflammation. Moreover, inhibition of periostin blocks spontaneous firing of superficial dorsal horn neurons followed by a decrease in scratching behaviors due to itching. Taken together, periostin links NF-κB-mediated inflammation with type 2 inflammation and promotes itching in allergic skin inflammation, suggesting that periostin is a promising therapeutic target for AD.

IL-13, periostin and dipeptidyl-peptidase-4 reveal endotype-phenotype associations in atopic dermatitis

BACKGROUND

The heterogeneous (endo)phenotypes of atopic dermatitis (AD) require precision medicine. Currently, systemic therapy is recommended to patients with an Eczema Area and Severity Index (EASI)≥16. Previous studies have demonstrated an improved treatment response to the anti-interleukin (IL)-13 antibody tralokinumab in AD subgroups with elevated levels of the IL-13-related biomarkers dipeptidyl-peptidase (DPP)-4 and periostin.

METHODS

Herein, 373 AD patients aged≥12 years were stratified by IL-13high , periostinhigh and DPP-4high endotypes using cross-sectional data from the ProRaD cohort Bonn. "High" was defined as >80th quantile of 47 non-atopic controls. We analyzed endotype-phenotype associations using machine-learning gradient boosting compared to logistic regression.

RESULTS

AD severity and eosinophils correlated with IL-13 and periostin levels. Correlations of IL-13 with EASI were stronger in patients with increased (rs=0.482) than with normal (rs=0.342) periostin levels. We identified eosinophilia>6% and an EASI range of 5.5-17 dependent on the biomarker combination to be associated with increasing probabilities of biomarkerhigh endotypes. Also patients with mild-to-low-moderate severity (EASI<16) featured increased biomarkers (IL-13high : 41%, periostinhigh : 48.4%, DPP-4high : 22.3%). Herthoge sign (adjusted Odds Ratio (aOR)=1.89, 95% Confidence Interval (CI) [1.14-3.14]) and maternal allergic rhinitis (aOR=2.79-4.47) increased the probability of an IL-13high -endotype, "dirty neck" (aOR=2.83 [1.32-6.07]), orbital darkening (aOR=2.43 [1.08-5.50]), keratosis pilaris (aOR=2.21 [1.1-4.42]) and perleche (aOR=3.44 [1.72-6.86]) of a DPP-4high -endotype.

CONCLUSIONS

A substantial proportion of patients with EASI<16 featured high biomarker levels suggesting systemic impact of skin inflammation already below the current cut-off for systemic therapy. Our findings facilitate the identification of patients with distinct endotypes potentially linked to response to IL-13-targeted therapy.

Immunopathogenesis of Atopic Dermatitis: Focus on Interleukins as Disease Drivers and Therapeutic Targets for Novel Treatments

Atopic dermatitis is a chronic, recurrent inflammatory skin disorder manifesting by eczematous lesions and intense pruritus. Atopic dermatitis develops primarily as a result of an epidermal barrier defect and immunological imbalance. Advances in understanding these pathogenetic hallmarks, and particularly the complex role of interleukins as atopic dermatitis drivers, resulted in achieving significant therapeutic breakthroughs. Novel medications involve monoclonal antibodies specifically blocking the function of selected interleukins and small molecules such as Janus kinase inhibitors limiting downstream signaling to reduce the expression of a wider array of proinflammatory factors. Nevertheless, a subset of patients remains refractory to those treatments, highlighting the complexity of atopic dermatitis immunopathogenesis in different populations. In this review, we address the immunological heterogeneity of atopic dermatitis endotypes and phenotypes and present novel interleukin-oriented therapies for this disease.

Tailored treatments in inborn errors of immunity associated with atopy (IEIs-A) with skin involvement

Inborn errors of immunity associated with atopy (IEIs-A) are a group of inherited monogenic disorders that occur with immune dysregulation and frequent skin involvement. Several pathways are involved in the pathogenesis of these conditions, including immune system defects, alterations of skin barrier and metabolism perturbations. Current technological improvements and the higher accessibility to genetic testing, recently allowed the identification of novel molecular pathways involved in IEIs-A, also informing on potential tailored therapeutic strategies. Compared to other systemic therapy for skin diseases, biologics have the less toxic and the best tolerated profile in the setting of immune dysregulation. Here, we review IEIs-A with skin involvement focusing on the tailored therapeutic approach according to their pathogenetic mechanism.

KIR Allelic Variation and the Remission of Atopic Dermatitis Over Time

Atopic dermatitis (AD) is a common chronic skin disease. Although generally thought to be a disease of T-cell dysregulation, recent studies have suggested that immune dysregulation of NK cells is also important. Killer cell Ig-like receptors (KIRs) are involved with NK cell regulation. The Pediatric Eczema Elective Registry is a U.S. nationwide longitudinal cohort with up to 10 y of follow-up in which 655 children had DNA available for full allelic KIR sequencing. Every 6 mo, AD activity was reported by Pediatric Eczema Elective Registry children. Using generalized estimating equations, we evaluated the association of KIR allelic variation in concert with known HLA binding ligands and whether the child reported AD in "remission" (no skin lesions and not using AD medication). KIR2DS4*001:01 (odds ratio 0.53, 95% CI [0.32, 0.88]) and KIR2DL4*001:02 (0.54, [0.33, 0.89]) in the presence of C*04:01 had the largest effect on decreasing the likelihood of AD remission. The haplotype KIR 2DL4*001:02 ∼ 2DS4*001:01 ∼ 3DL2*002:01 (0.77, [0.60, 0.99]) was also associated with a decreased likelihood of AD remission. Our findings add to the general body of evidence of a growing literature on the importance of NK cells with respect to the immunopathogenesis and natural history of AD.

Inhibitory Effect of Bisdemethoxycurcumin on DNCB-Induced Atopic Dermatitis in Mice

Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Bisdemethoxycurcumin (BDMC) is an ingredient from the rhizome of the traditional Chinese herbal medicine turmeric. BDMC has been reported to have important pharmacological properties, such as anti-inflammatory, antioxidant, antitumor and antiproliferative activities. However, its effect on atopic dermatitis has not been reported. The purpose of our study was to demonstrate the effectiveness of BDMC on TNF-α/IFNγ-stimulated HaCaT cells and on 2,4-dinitrochlorobenzene (DNCB)-induced AD mice. Our studies showed in vitro that BDMC was able to significantly inhibit the mRNA expression of chemokines and cytokines in TNF-α/IFN-γ-stimulated HaCaT cells and alleviate their inflammatory response. Our studies found in vivo that BDMC was able to significantly improve the symptoms of DNCB-induced AD skin lesions, decrease the number of scratches, ear thickness, and spleen index, improve inflammatory cells and mast cell infiltration and decrease skin thickness. Moreover, it was also able to inhibit the mRNA expression levels of chemokines and inflammatory cytokines and the activation of the MAPK and NF-κB signaling pathways. Thus, the results indicated that BDMC can improve atopic dermatitis in mice and that further clinical studies are warranted on its treatment of AD.

Current Insight into the Role of IL-35 and Its Potential Involvement in the Pathogenesis and Therapy of Atopic Dermatitis

Interleukin 35 (IL-35), a new member of the IL-12 family of heterodimeric cytokines, could induce two different types of regulatory cells including regulatory T and B cells such as IL-35-induced regulatory T cells and IL-10-producing regulatory B cells (IL-10+Bregs), and IL-35-producing regulatory B cells (IL-35+Bregs). These cells appear to play an important role in modulating the immune system in numerous diseases. Several findings suggested that the expression of IL-35 is dysregulated in many autoimmune, inflammatory, and allergic diseases. Due to the functions of IL-35, it seems that this cytokine may act as an efficient therapeutic strategy for numerous conditions including atopic dermatitis (AD). We aimed to provide a comprehensive overview of the role of IL-35 in modulating the immune system. Additionally, we highlight IL-35 as a specific immunological target, discuss its possible involvement in the pathogenesis of AD, and hypothesize that IL-35 may become a novel target for the treatment of AD. However, further studies are required to evaluate this hypothesis.

OX40-OX40L Inhibition for the Treatment of Atopic Dermatitis-Focus on Rocatinlimab and Amlitelimab

Despite the recent emergence of targeted therapeutic options, there are still unmet needs concerning moderate-to-severe atopic dermatitis treatment. This review aims to discuss the OX40-OX40L pathway as a therapeutic target for the treatment of atopic dermatitis. OX40 and OX40L are two checkpoint molecules that bind to potentiate pro-inflammatory T-cell responses that are pivotal to atopic dermatitis pathogenesis. Two OX40-OX40L inhibitors, rocatinlimab and amlitelimab, are being developed for the treatment of atopic dermatitis. Rocatinlimab, an anti-OX40 antibody, was evaluated in phase 2b, a randomized, placebo-controlled clinical trial. At week 16, rocatinlimab groups achieved a greater reduction in the EASI percentage change from the baseline (−48.3% to −61.1%) against the placebo (−15.0%; p < 0.001), and clinical response was maintained 20 weeks after the treatment had ceased. Amlitelimab, an anti-OX40L antibody, was studied in a 12-week treatment phase 2a clinical trial, with a significant efficacy response observed within 2 weeks. At week 16, amlitelimab groups reached the EASI mean percentage change from the baseline of −69.9% and −80.1% versus the placebo (−49.4%; p = 0.072 and p = 0.009). Among the responders, 68% of amlitelimab patients were sustained 24 weeks following the last dose. Both treatments were shown to be safe and well tolerated. Current evidence points to OX40-OX40L inhibitors as future options for atopic dermatitis treatment with potential disease-modifying effects.

An Altered Skin and Gut Microbiota Are Involved in the Modulation of Itch in Atopic Dermatitis

Skin and gut microbiota play an important role in the pathogenesis of atopic dermatitis (AD). An alteration of the microbiota diversity modulates the development and course of AD, e.g., decreased microbiome diversity correlates with disease severity, particularly in lesional skin of AD. Itch is a hallmark of AD with unsatisfying treatment until now. Recent evidence suggests a possible role of microbiota in altering itch in AD through gut-skin-brain interactions. The microbial metabolites, proinflammatory cytokines, and impaired immune response lead to a modulation of histamine-independent itch, disruption of epidermal barrier, and central sensitization of itch mechanisms. The positive impact of probiotics in alleviating itch in AD supports this hypothesis, which may lead to novel strategies for managing itchy skin in AD patients. This review summarizes the emerging findings on the correlation between an altered microbiota and gut-skin-brain axis in AD, especially in modulating itchy skin.

Children atopic dermatitis: Diagnosis, mimics, overlaps, and therapeutic implication

Atopic dermatitis (AD) is a chronic inflammatory, itching skin with a significant psychosocial impact on patients and relatives. In adults and adolescents besides flexural eczema, head and neck eczema, and hand eczema, which are the most frequent clinical phenotypes (84.9% and 84.2%, respectively), there are also other possible presentation such as, portrait-like dermatitis (20.1%), diffuse eczema (6.5%), eczema nummulare-like (5.8%), prurigo nodularis-like (2.1%) and erythrodermia (0.7%). Diagnosis can be easy due to the typically distributed eczematous lesions, albeit with age-related differences, However, it is also extremely heterogeneous in severity, course, and sometimes particular clinical features. Currently, there are no better diagnostic criteria than an experienced dermatologist for the diagnosis of AD. Misdiagnosis and delayed treatment will have an impact not only on the child's physical health, but also and especially on the child's psychological health. The aim of our review was to group the main differential diagnoses in pediatric age where the diagnosis can often hide many pitfalls.

Variations in genetics, biology, and phenotype of cutaneous disorders in skin of color. Part II: Differences in clinical presentation and disparities in cutaneous disorders in skin of color

Skin of color (SOC) patients are projected to comprise the majority of the population by 2044, yet knowledge gaps in the clinical presentation and treatment of both common and uncommon dermatologic conditions in skin of color persist. Improved awareness of disparities that disproportionately impact SOC patients is necessary to address health inequity in the field of dermatology. The first part of this CME discussed structural, genetic, and immunophenotypic differences in SOC in common inflammatory disorders as well as cutaneous malignancies. The second part of this CME highlights clinical differences in the phenotypic presentation of the inflammatory disorders of atopic dermatitis, psoriasis, and hidradenitis suppurativa as well as the cutaneous malignancies of melanoma, basal cell carcinoma, and cutaneous T-cell lymphoma. Health disparities associated with each of these conditions are also discussed.

Variations in genetics, biology, and phenotype of cutaneous disorders in skin of color - Part I: Genetic, biologic, and structural differences in skin of color

Skin of color (SOC) populations include those who identify as Black/African, Hispanic/Latinx, Asian/Pacific Islander, American Indian/Native Alaskan, Indigenous Australian, Middle Eastern, biracial/multiracial, or non-White; this list is far from exhaustive and may vary between and within cultures. Recent genetic and immunological studies have suggested that cutaneous inflammatory disorders (atopic dermatitis, psoriasis, and hidradenitis suppurativa) and malignancies (melanoma, basal cell carcinoma, and cutaneous T-cell lymphoma) may have variations in their immunophenotype among SOC. Additionally, there is growing recognition of the substantial role social determinants of health play in driving health inequalities in SOC communities. It is critically important to understand that social determinants of health often play a larger role than biologic or genetic factors attributed to "race" in health care outcomes. Herein, we describe the structural, genetic, and immunological variations and the potential implications of these variations in populations with SOC. This article underscores the importance of increasing the number of large, robust genetic studies of cutaneous disorders in SOC to create more targeted, effective therapies for this often underserved and understudied population. Part II of this CME will highlight the clinical differences in the phenotypic presentation of and the health disparities associated with the aforementioned cutaneous disorders in SOC.

Glycyrrhizic acid suppresses atopic dermatitis-like symptoms by regulating the immune balance

BACKGROUND

Glycyrrhiza is one of the most widely used traditional Chinese medicines in China. Its main bioactive ingredient glycyrrhizic acid (GA) has the potential to be used as a treatment for atopic dermatitis (AD) because it has similar actions to steroids, but with relatively few side effects.

AIMS

The objective of this study was to explore the potential mechanisms of GA on AD mice model.

METHODS

Calcipotriol, a vitamin D3 analogue (MC903) was applied topically to establish AD mouse model. Mice were intraperitoneally administrated with 2 mg/kg dexamethasone (DEX), 25 or 50 mg/kg GA for 15 days. After mice were executed, skin tissues were collected and detected the expression levels of IL-4, IFN-γ, TNF-α and thymic stromal lymphopoietin (TSLP). The percentages of Th1, Th2, Th17, langerhans cells (LCs) in draining lymph nodes (dLNs) were measured by flow cytometry.

RESULTS

Our data demonstrated that GA improved the symptoms of AD by exerting anti-inflammatory and anti-allergic functions in vivo. We found that GA treatment decreased the level of total IgE in serum, suppressed ear swelling, reduced the infiltration of mast cells in skin lesions and decreased expressions of IL-4, IFN-γ, TNF-α and TSLP in skin lesions. Furthermore, our experimental results demonstrated that GA suppressed the Th1/Th2/Th17-immune responses in the dLNs, inhibited the migration of LCs in dLNs.

CONCLUSIONS

In conclusion, our findings suggested potential therapeutic effects of GA against MC903-induced AD-like skin lesions in mice.

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.

Post-Inflammatory Hyperpigmentation in Dark Skin: Molecular Mechanism and Skincare Implications

Human skin is characterized by significant diversity in color and tone, which are determined by the quantity and distribution of melanin pigment in the epidermis. Melanin absorbs and reflects ultraviolet radiation (UVR), preventing the damage to genomic DNA in the epidermis and degradation of collagen in the dermis; therefore, darker skin types are thought to be well protected from the photodamage because of the high melanin content. However, increased content of melanin in combination with the extrinsic stress factors causing inflammation such as excess UVR, allergic reactions, or injury can also frequently lead to cosmetic problems resulting in discoloration and scarring. This review summarizes current knowledge on histopathology and likely molecular signatures of one of the most common problems, post-inflammatory hyperpigmentation (PIH). The mechanisms proposed so far are subsequently discussed in the context of other factors characterizing darker skin types. This includes the common cellular features, organization of upper skin layers, and major biomarkers, with particular emphasis on increased propensities to systemic and localized inflammation. Enhanced or prolonged inflammatory responses can not only affect the process of melanogenesis but also have been implicated in injury-related skin pathologies and aging. Finally, we summarize the major cosmetic treatments for PIH and their known anti-inflammatory targets, which can be beneficial for darker skin tones and combined with broad-spectrum filters against UVR.

Atopic dermatitis across the life course

Atopic dermatitis, the most common chronic inflammatory skin disease, can occur at any age, and patterns of disease activity vary over time. Both prevalence and incidence are highest in infancy and early childhood, followed by a second peak in older adulthood. Birth cohort studies from European countries following children through adolescence have identified subgroups of patients with early-onset persistent disease, early-onset resolving disease, and later-onset disease. Parental history of atopy and genetic factors are among the most consistent predictors of more persistent disease. Studies have begun to examine whether molecular markers differ by age group, although longitudinal data are lacking. Breastfeeding, probiotics and skin-directed therapies such as emollients have been investigated as potential preventive measures, but randomized trials have not found consistent long-term benefit. Future research should focus on patterns of disease activity beyond early adulthood and the role of treatments on long-term disease activity.

Atopic Dermatitis: Clinical Aspects and Unmet Needs

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

No Association Between First Exposure to General Anaesthesia and Atopic Dermatitis in the Paediatric Population

General anaesthesia could affect various immune responses, including Th1 and Th2 immunity, which might also affect cells that play an important role in the pathogenesis of atopic dermatitis. However, the relationship between general anaesthesia exposure and atopic dermatitis remains unknown. The aim of this study was to investigate the risk of developing atopic dermatitis after first exposure to general anaesthesia in the paediatric population (18 years or under). A retrospective cohort study, including those exposed (n = 7,681) and unexposed (n = 38,405; control participants) to general anaesthesia (1:5 ratio), was conducted using national sample cohort data from 2002 to 2015. All participants were followed up for 2 years after cohort entry. The 2-year cumulative incidences of atopic dermatitis in the exposed and unexposed groups were 2.3% and 2.2%, respectively. In the subgroup analysis by age, the cumulative incidence was not significantly different between these cohorts. The risks of atopic dermatitis were not significant in the exposed group in the univariate model (hazard ratio 1.05; confidence interval 0.88-1.24) and in the multivariate model, wherein all covariates were adjusted (adjusted hazard ratio, 1.03; 95% confidence interval 0.87-1.23). The results suggest that children's exposure to general anaesthesia was not associated with increased or decreased risk of atopic dermatitis.

Therapeutical Targets in Allergic Inflammation

From the discovery of IgE to the in-depth characterization of Th2 cells and ILC2, allergic inflammation has been extensively addressed to find potential therapeutical targets. To date, omalizumab, an anti-IgE monoclonal antibody, and dupilumab, an anti-IL-4 receptor α monoclonal antibody, represent two pillars of biologic therapy of allergic inflammation. Their increasing indications and long-term follow-up studies are shaping the many different faces of allergy. At the same time, their limitations are showing the intricate pathogenesis of allergic diseases.

Novel Interactions of Myristic Acid and FADS3 Variants Predict Atopic Dermatitis among Indonesian Infants

Fatty acids exert a range of different biological activities that could be relevant in the development of atopic dermatitis (AD). This study investigated the association of glycerophospholipid fatty acids (GPL-FA) with AD, and their interactions with single nucleotide polymorphisms (SNP) of the FADS1-3 gene cluster. Among 390 infants of the Indonesian ISADI study, GPL-FA were measured in umbilical plasma (P-0y) and in buccal cells at birth (B-0y), and again in buccal cells at AD onset or one year (B-1y). Prospective and cross-sectional associations with AD were assessed by logistic regression. Interactions of GPL-FA with 14 SNP were tested assuming an additive model. AD was diagnosed in 15.4% of participants. In B-1y, C18:2n-6 was inversely associated with AD; and positive associations were observed for C18:1n-9, C20:4n-6, C22:6n-3 and C20:4n-6/C18:2n-6. There were no prospective associations with AD, however, a significant interaction between the SNP rs174449 and B-0y C14:0 (myristic acid) was observed. This study indicates that Indonesian infants with AD have increased rates of endogenous long-chain polyunsaturated fatty acid production, as well as higher C18:1n-9 levels. GPL-FA measured at birth do not predict later AD incidence; however, genotype interactions reveal novel effects of myristic acid, which are modified by a FADS3 variant.

A pathogenic integrated view explaining the different endotypes of asthma and allergic disorders

The inflammation of allergic diseases is characterized by a complex interaction between type 2 and type 3 immune responses, explaining clinical symptoms and histopathological patterns. Airborne stimuli activate the mucosal epithelium to release a number of molecules impacting the activity of resident immune and environmental cells. Signals from the mucosal barrier, regulatory cells, and the inflamed tissue are crucial conditions able to modify innate and adaptive effector cells providing the selective homing of eosinophils or neutrophils. The high plasticity of resident T- and innate lymphoid cells responding to external signals is the prerequisite to explain the multiplicity of endotypes of allergic diseases. This notion paved the way for the huge use of specific biologic drugs interfering with pathogenic mechanisms of inflammation. Based on the response of the epithelial barrier, the activity of resident regulatory cells, and functions of structural non-lymphoid environmental cells, this review proposes some immunopathogenic scenarios characterizing the principal endotypes which can be associated with a precise phenotype of asthma. Recent literature indicates that similar concepts can also be applied to the inflammation of other non-respiratory allergic disorders. The next challenges will consist in defining specific biomarker(s) of each endotype allowing for a quick diagnosis and the most effective personalized therapy.

Pro-Inflammatory versus Anti-Inflammatory cytokines in atopic dermatitis patients: A case control study

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disorder with significant morbidity and impairment of life quality. Prevalence is increasing around the world; therefore, intensive research is ongoing to understand the mechanisms of development of AD and offer new treatment options for AD patients.

AIMS

To investigate the association between Inflammatory (IL-17, TNF-α, IFN-γ) versus anti-Inflammatory Cytokines (IL-35, TGF-β) in AD patients.

PATIENTS AND METHODS

A case control study included 40 AD patients and 20 age- and sex-matched healthy subjects. Cases were subjected to full history taking and full dermatological examination. The assessment of disease severity was conducted by using SCORAD score. Assessment of inflammatory (IL-17, TNF-α, IFN-γ) and anti-Inflammatory Cytokines (IL-35, TGF-β) was performed by using ELISA technique.

RESULTS

The mean level of TNF-α, IL-17 was statistically significantly higher in the AD cases as compared with the control group. The mean level of TGF-β, Il-35, and IFN-γ was statistically significantly lower in the Atopic dermatitis cases as compared with the control group. There was statistically significant strong positive correlation between TNF-α with SCORAD score and IL-17 while there was statistically significant strong negative correlation between TNF-α with TGF-β and IL-35. There was statistically significant strong positive correlation between IL-17 with SCORAD score and TNF-α while there was statistically significant strong negative correlation between IL-17 with TGF-β and IL-35.

CONCLUSION

The current results could be used as a clue for the utilization of inflammatory (IL-17, TNF-α, IFN-γ) versus anti-inflammatory Cytokines (IL-35, TGF-β) in AD as a diagnostic biomarker for severity of cases with Atopic dermatitis. IL-17 plays an important role in the pathogenesis of AD, and IL-17 blocker may be used as a potential future treatment of AD.

Management of Atopic Dermatitis: Clinical Utility of Ruxolitinib

Atopic dermatitis (AD) is a common chronic, pruritic inflammatory skin disease that profoundly impacts patients' quality of life. As the first FDA-approved topical JAK inhibitor, ruxolitinib 1.5% cream represents a novel therapeutic topical agent for the treatment of AD. The objective of this review is to summarize the efficacy and safety of ruxolitinib cream in patients with AD based on the available evidence. Overall, ruxolitinib cream demonstrated high efficacy and a favorable safety profile for treating atopic dermatitis.

Clinical Implication of Serum Adiponectin Levels in Adult Patients with Atopic Dermatitis

Atopic dermatitis (AD) is characterized by chronic, relapsing, pruritic inflammatory skin disease. Adiponectin has been reported to have anti-inflammatory effects not only on metabolic disorders but also on various inflammatory disorders. The study aimed to validate adiponectin as a potential biomarker for AD disease severity and treatment response. Seventy-five patients with AD and 28 healthy volunteers were enrolled in the study. Patient information, including Eczema Area and Severity Index (EASI) scores and pruritus numeric rating scales (NRSs), were collected. An enzyme linked immunosorbent assay (ELISA) was conducted to measure levels of serum adiponectin. Additionally, sera of patients treated with dupilumab were collected and measured at 16 and 52 weeks from baseline. Serum adiponectin levels were significantly lower in moderate and severe AD patients than in the control and mild AD patients. Serum adiponectin level was negatively correlated with the EASI score and pruritus NRS. However, no significant changes were observed according to biologic treatment for AD. Low serum adiponectin levels are associated with moderate to severe AD, suggesting a potential role for adiponectin as a biomarker for severity assessment of AD.

Dupilumab Treatment in Adults with Moderate-to-Severe Atopic Dermatitis is Efficacious Regardless of Age of Disease Onset: a Post Hoc Analysis of Two Phase 3 Clinical Trials

INTRODUCTION

Adults with atopic dermatitis (AD) commonly report adult-onset disease. AD is associated with different genetics, lesion morphology and distribution, and symptoms by age of onset. Yet little is known about possible differences in treatment efficacy between adults with adult-onset or childhood-onset AD.

METHODS

We evaluated the efficacy of dupilumab by age of AD onset in adults with moderate-to-severe AD, using pooled data from the LIBERTY AD SOLO 1 and 2 studies (NCT02277743, NCT02277769). Results were stratified based on self-reported age of AD onset, divided into four age subgroups: 0-4, 5-9, 10-19, and over 20 years.

RESULTS

This analysis included 460 patients treated with placebo and 457 treated with dupilumab 300 mg every 2 weeks (q2w), with a mean patient age of 38 years. Most patients (53.2%) reported AD onset at 0-4 years, with 14% at 5-9 years, 13.4% at 10-19 years, and 18.5% at 20 years or older. Dupilumab significantly improved AD signs and symptoms over 16 weeks compared with placebo, regardless of age of onset. Dupilumab treatment resulted in a significantly greater proportion of patients achieving Eczema Area and Severity Index (EASI)-50, EASI-75, and EASI-90 (50%, 75%, and 90% improvement from baseline EASI, respectively), and clear or almost clear skin (Investigator's Global Assessment score 0 or 1) across all age-of-onset subgroups compared with placebo. In addition, EASI improvements were significant across all anatomical regions in all subgroups. Weekly average peak pruritus Numerical Rating Scale and Dermatology Life Quality Index also improved consistently and significantly with dupilumab versus placebo, regardless of age of onset.

CONCLUSION

Despite possible differences in presentation and progression of AD linked to age of onset, dupilumab showed similar significant and sustained improvements in AD signs, symptoms, and quality of life in adults compared with placebo, over 16 weeks of treatment.

TRIAL REGISTRATION

LIBERTY AD SOLO 1: NCT02277743; LIBERTY AD SOLO 2: NCT02277769. Infographic available for this article.

Efficacy and safety of Chinese herbal medicine for atopic dermatitis: Evidence from eight high-quality randomized placebo-controlled trials

Background: The use of Chinese herbal medicine (CHM) for the treatment of atopic dermatitis (AD) has gained attention. This quantitative study systematically evaluated the efficacy and safety of CHM for the treatment of AD in eight high-level clinical trials, resulting in a high level of clinical evidence.

Methods: Several databases were searched, including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), the Chongqing VIP Chinese Science (VIP), and Wanfang Database. High-quality randomized controlled trials (RCTs) comparing CHM with placebo were included. The 95% confidence interval (CI) of the risk ratio (RR) was calculated using software (RevMan 5.3) and a meta-analysis was performed. Evidence level evaluation using GRADE Profiler 3.6.

Results: In total, 662 patients (322 in the experimental group and 340 in the control group) were included. The response rate of the Eczema Area and Severity Index (EASI) −90 was higher in the CHM group than in the placebo group (RR, 3.72; 95% CI, 1.76 to7.83; p = 0.01). Furthermore, the scoring of atopic dermatitis (SCORAD) (RR, −10.20), body surface area (BSA) (RR, −2.01), surface damage score (RR, −2.25), visual analog scale (VAS) (RR, −1.90), and sleep score (RR, −2.16), improvement of investigator’s global assessment (IGA) (RR, 2.94) improved in the CHM group. The results showed no statistical difference between CHM and placebo (MD, −0.47; 95% CI, −1.30, 0.37; p = 0.27) in improving the Dermatology Life Quality Index (DLQI) or children’s DLQI (CDLQI). There was also no significant difference in the IgE level between the two groups (MD, −62.76; 95% CI, −809.58, 684.05; p = 0.87). However, the adverse events (AEs) rate was slightly higher in patients treated with CHM than in those treated with placebo (RR, 1.42; 95% CI, 1.06–1.90; p = 0.02).

Conclusion: CHM improved the size and severity of the skin lesions and sleep quality in patients with AD. Comparing the adverse effects between the two groups, CHM is safe. However, CHM does not improve the quality of life or the patient’s IgE levels.