Itch in Atopic Dermatitis - What Is New?

Efficacy, Safety, and Long-Term Disease Control of Ruxolitinib Cream Among Adolescents with Atopic Dermatitis: Pooled Results from Two Randomized Phase 3 Studies

BACKGROUND

Atopic dermatitis (AD), a highly pruritic, inflammatory skin disease, affects approximately 7% of adolescents globally. A topical formulation of ruxolitinib, a Janus kinase (JAK) 1/JAK2 inhibitor, demonstrated safety and efficacy among adolescents/adults in two phase 3 studies (TRuE-AD1/TRuE-AD2).

OBJECTIVE

To describe safety and efficacy of 1.5% ruxolitinib cream versus vehicle and long-term disease control of ruxolitinib cream among adolescents aged 12-17 years from pooled phase 3 study data.

METHODS

Patients [≥ 12 years old with AD for ≥ 2 years, Investigator's Global Assessment score (IGA) 2/3, and 3-20% affected body surface area (BSA) at baseline] were randomized 2:2:1 to ruxolitinib cream (0.75%/1.5%) or vehicle for 8 weeks of continuous use followed by a long-term safety (LTS) period up to 52 weeks with as-needed use. Patients originally applying vehicle were rerandomized 1:1 to 0.75%/1.5% ruxolitinib cream. Efficacy measures at week 8 included IGA treatment success (IGA-TS; i.e., score of 0/1 with ≥ 2 grade improvement from baseline), ≥ 75% improvement in Eczema Area and Severity Index (EASI-75), and ≥ 4-point improvement in itch numerical rating scale (NRS4). Measures of disease control during the LTS period included IGA score of 0 (clear) or 1 (almost clear) and percentage affected BSA. Safety was assessed throughout the study.

RESULTS

Of 1249 randomized patients, 245 (19.6%) were aged 12-17 years. Of these, 45 patients were randomized to vehicle and 92 patients to 1.5% ruxolitinib cream. A total of 104/137 (75.9%) patients continued on 1.5% ruxolitinib cream in the LTS period [82/92 (89.1%) continued on 1.5% ruxolitinib cream; 22/45 (48.9%) patients on vehicle were reassigned to 1.5% ruxolitinib cream], and 83/104 (79.8%) of these patients completed the LTS period. At week 8, substantially more patients who applied 1.5% ruxolitinib cream versus vehicle achieved IGA-TS (50.6% versus 14.0%), EASI-75 (60.9% versus 34.9%), and NRS4 (52.1% versus 17.4%; P = 0.009). The mean (SD) reduction in itch NRS scores was significantly greater in patients applying 1.5% ruxolitinib cream versus vehicle from day 2 [- 0.9 (1.9) versus -0.2 (1.4); P = 0.03]. During the LTS period, mean (SD) trough steady-state ruxolitinib plasma concentrations at weeks 12/52 were 27.2 (55.7)/15.5 (31.5) nM. The percentage of patients achieving IGA score of 0 or 1 was sustained or further increased with 1.5% ruxolitinib cream; mean affected BSA was generally low (< 3%; i.e., mild disease). Through 52 weeks, application site reactions occurred in 1.8% of adolescent patients applying 1.5% ruxolitinib cream at any time; no patients had serious adverse events. There were no serious infections, malignancies, major adverse cardiovascular events, or thromboembolic events.

CONCLUSIONS

Meaningful anti-inflammatory and antipruritic effects were demonstrated with 1.5% ruxolitinib cream in the subset of adolescent patients with AD, comparable with those observed in the overall study population; long-term, as-needed use maintained disease control and was well tolerated.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifiers NCT03745638 (registered 19 November 2018) and NCT03745651 (registered 19 November 2018).

Atopic dermatitis in early life and pain at 10 years of age: An exploratory study

Pain is a distinctive burden in atopic dermatitis and recognized as an important and highly prevalent symptom. It is unknown if the presence of atopic disease may sensitize children to adverse pain profiles in the long term. We aimed to assess the impact of early-life atopic dermatitis-like symptoms on pain at 10 years of age. We used data from 1302 and 874 participants of the Generation XXI birth cohort evaluated at 6 and 15 months, respectively, and 10 years. Atopy-like symptoms since birth, including atopic dermatitis, were collected at ages 6 and 15 months by interviewing parents. Pain history in the last 3 months at age 10 was collected from parents and children using structured questionnaires. We computed relative risks (RR) and respective 95% confidence intervals of pain features at age 10 according to each atopic-like symptom at 6 and 15 months. Children whose parents reported atopic dermatitis-like symptoms at 6 months and at 15 months had higher risk of reporting any pain (RR 1.75 [1.15-2.66]) and multisite pain, respectively (RR 1.67 [1.18-2.37]) at 10 years of age.  Conclusion: Atopic dermatitis symptoms in early life were associated with a higher risk of pain at age 10, suggesting that potential for sensitization during the first decade of life and highlighting the importance of improving the health care of children with atopic dermatitis is worth investigating. What is Known: • Atopic disorders have been associated with many non-atopic comorbidities, including chronic pain. • Pain and atopic dermatitis share common inflammatory pathways. Inflammation, injury to the skin from scratching, fissures, and intolerance to irritants related to atopic dermatitis can cause pain. What is New: • Atopic dermatitis in early life is linked to an increased likelihood of experiencing pain at the age of 10, which suggests that exploring the potential for sensitization is a worthwhile area of investigation. • Our proof-of-concept study highlights the potential benefit of studying management targets and improving itching and relieving skin pain as quickly as possible, avoiding potential long-term consequences of the sensitization process.

[Health-related quality of life : Concept, measurement and fields of application]

Health-related quality of life (HRQoL) is the most important patient-reported outcome in clinical trials and patient care. HRQoL is further considered as target variable in treatment guidelines and as outcome indicator in the evaluation of the quality of care. Numerous validated questionnaires are available for the assessment of HRQoL from the perspective of patients with skin diseases. However, many are of inadequate methodological quality, indicating the need for further research in the development of high-quality measurement instruments. The implementation of routine electronic HRQoL assessments is a promising approach.

Economic Burden of Itch-Related Sleep Loss in Moderate-to-Severe Atopic Dermatitis in the United Kingdom

INTRODUCTION

Atopic dermatitis is associated with intense itch, which has been shown to cause sleep disruption that significantly impacts the lives of patients with atopic dermatitis. Despite this, little is known about its burden to the healthcare system and society. This study aimed to quantify the economic burden of itch-related sleep loss in moderate-to-severe atopic dermatitis in the UK.

METHODS

A literature-based decision-analytic model was developed from a healthcare payer and societal perspective. The model quantifies the economic burden by linking the severity of itch to the number of days of sleep disruption. The model captures the direct costs of healthcare resource utilization and treatment alongside the indirect costs of productivity loss from absenteeism and presenteeism at work over a 5-year time horizon. The patient population considered was patients aged ≥ 15 years with moderate-to-severe atopic dermatitis and itch-related sleep disruption.

RESULTS

The model estimated that itch-related sleep disruption as a result of moderate-to-severe atopic dermatitis would affect an average of 821,142 people over the time horizon (2022 to 2026). This translates into an average net economic burden of £3.8 billion (£4687 per patient), with an average of 172 million days being affected by sleep disruption per year in the UK. The greatest contributor to the annual average net economic burden was productivity loss from absenteeism and presenteeism, each accounting for 34%. The direct costs (treatment costs and healthcare resource use) accounted for 32% of the net economic burden. The results showed a high and gradually increasing economic burden over the 5-year time horizon.

CONCLUSIONS

Sleep disruption has a high economic burden and reducing itch may provide substantial direct and indirect savings. Quantifying the economic burden of itch-related sleep loss may provide support for analyses to inform public health policies for treatment of atopic dermatitis, particularly within the moderate-to-severe level.

Small-molecule agents for treating skin diseases

Skin diseases are a class of common and frequently occurring diseases that significantly impact daily lives. Currently, the limited effective therapeutic drugs are far from meeting the clinical needs; most drugs typically only provide symptomatic relief rather than a cure. Developing small-molecule drugs with improved efficacy holds paramount importance for treating skin diseases. This review aimed to systematically introduce the pathogenesis of common skin diseases in daily life, list related drugs applied in the clinic, and summarize the clinical research status of candidate drugs and the latest research progress of candidate compounds in the drug discovery stage. Also, it statistically analyzed the number of publications and global attention trends for the involved skin diseases. This review might provide practical information for researchers engaged in dermatological drugs and further increase research attention to this disease area.

Unraveling the skin; a comprehensive review of atopic dermatitis, current understanding, and approaches

Atopic dermatitis, also known as atopic eczema, is a chronic inflammatory skin disease characterized by red pruritic skin lesions, xerosis, ichthyosis, and skin pain. Among the social impacts of atopic dermatitis are difficulties and detachment in relationships and social stigmatization. Additionally, atopic dermatitis is known to cause sleep disturbance, anxiety, hyperactivity, and depression. Although the pathological process behind atopic dermatitis is not fully known, it appears to be a combination of epidermal barrier dysfunction and immune dysregulation. Skin is the largest organ of the human body which acts as a mechanical barrier to toxins and UV light and a natural barrier against water loss. Both functions face significant challenges due to atopic dermatitis. The list of factors that can potentially trigger or contribute to atopic dermatitis is extensive, ranging from genetic factors, family history, dietary choices, immune triggers, and environmental factors. Consequently, prevention, early clinical diagnosis, and effective treatment may be the only resolutions to combat this burdensome disease. Ensuring safe and targeted drug delivery to the skin layers, without reaching the systemic circulation is a promising option raised by nano-delivery systems in dermatology. In this review, we explored the current understanding and approaches of atopic dermatitis and outlined a range of the most recent therapeutics and dosage forms brought by nanotechnology. This review was conducted using PubMed, Google Scholar, and ScienceDirect databases.

The skin-brain connection and pleasant touch as supportive care for psychocutaneous disorders

Psychodermatology is a subdiscipline of dermatology at the intersection of dermatology, psychiatry, and psychology. In dermatology clinical practice, patients may present with skin disease that affects their mental health, or skin disorders induced or worsened by psychological/psychiatric problems so there is a need for specialised education of dermatologists, as well as multidisciplinary teams, to achieve better management of these patients. Understanding the interaction between the central nervous system and the skin underlying psychocutaneous disorders could help identify alternative therapies that may improve patient well-being. The concept of pleasurable touch has received increasing attention following the discovery of C-tactile (CT) fibres. While afferent C-fibre stimulation is usually associated with pain, temperature, or itch, CT-fibres are stimulated optimally by a stimulus not in the nociceptor range but by a gentle, low-force stroking. As this affective touch may counteract unpleasurable sensations, such as pain and itch, and elicit positive feelings, the potential benefits of gentle touch and massage are interesting for dermatological, especially psychocutaneous, disorders. Here we provide an overview of the skin-brain connection to help understand the benefits of touch and massage, as illustrated with studies on atopic dermatitis and burns, as an adjunct to dermatological treatment for improving patient well-being and optimising treatment outcomes.

Cutaneous Components Leading to Pruritus, Pain, and Neurosensitivity in Atopic Dermatitis: A Narrative Review

Atopic dermatitis (AD) is a chronic, relapsing immunoinflammatory skin condition characterized by sensations such as pruritis, pain, and neuronal hypersensitivity. The mechanisms underlying these sensations are multifactorial and involve complex crosstalk among several cutaneous components. This review explores the role these components play in the pathophysiology of atopic dermatitis. In the skin intercellular spaces, sensory nerves interact with keratinocytes and immune cells via myriad mediators and receptors. These interactions generate action potentials that transmit pruritis and pain signals from the peripheral nervous system to the brain. Keratinocytes, the most abundant cell type in the epidermis, are key effector cells, triggering crosstalk with immune cells and sensory neurons to elicit pruritis, pain, and inflammation. Filaggrin expression by keratinocytes is reduced in atopic dermatitis, causing a weakened skin barrier and elevated skin pH. Fibroblasts are the main cell type in the dermis and, in atopic dermatitis, appear to reduce keratinocyte differentiation, further weakening the skin barrier. Fibroblasts and mast cells promote inflammation while dermal dendritic cells appear to attenuate inflammation. Inflammatory cytokines and chemokines play a major role in AD pathogenesis. Type 2 immune responses typically generate pruritis, and the type 1 and type 3 responses generate pain. Type 2 responses and increased skin pH contribute to barrier dysfunction and promote dysbiosis of the skin microbiome, causing the proliferation of Staphyloccocus aureus. In conclusion, understanding the dynamic interactions between cutaneous components in AD could drive the development of therapies to improve the quality of life for patients with AD.

Interpreting the Relationship Among Itch, Sleep, and Work Productivity in Patients with Moderate-to-Severe Atopic Dermatitis: A Post Hoc Analysis of JADE MONO-2

BACKGROUND

Abrocitinib, an oral, once-daily Janus kinase 1-selective inhibitor, improved itch severity, sleep, and work productivity versus placebo in patients with moderate-to-severe atopic dermatitis.

OBJECTIVE

The aim of this study was to investigate relationships among itch, sleep, and work productivity in the phase III JADE MONO-2 clinical trial.

METHODS

A repeated-measures longitudinal model was used to examine relationships between itch (using the Peak Pruritus Numerical Rating Scale [PP-NRS] or Nighttime Itch Scale [NTIS]) and sleep disturbance/loss (using the Patient-Oriented Eczema Measure sleep item and SCORing AD Sleep Loss Visual Analog Scale) and, separately, between itch and work productivity (using the Work Productivity and Activity Impairment-Atopic Dermatitis Version 2.0 questionnaire). Mediation modelling was used to investigate the effect of treatment (abrocitinib vs placebo) on work impairment via improvements in itch and sleep.

RESULTS

The relationships between itch/sleep and itch/work productivity were approximately linear. PP-NRS scores of 0, 4-6, and 10 were associated with 0 days, 3-4 days, and 7 days per week of disturbed sleep, respectively. PP-NRS or NTIS scores of 0-1, 4-5, and 10 were associated with 0-10%, 20-30%, and >50% overall work impairment, respectively. Seventy-five percent of the effect of abrocitinib on reducing work impairment was indirectly mediated by improvement in itch, followed by sleep.

CONCLUSION

These results quantitatively demonstrate that reducing itch severity is associated with improvements in sleep and work productivity. Empirical evidence for the mechanism of action of abrocitinib showed that itch severity is improved, which reduces sleep loss/sleep disruption and, in turn, improves work productivity.

CLINICAL TRIAL REGISTRATION

NCT03575871.

Mind and skin: Exploring the links between inflammation, sleep disturbance and neurocognitive function in patients with atopic dermatitis

Atopic dermatitis (AD) is a chronic, pruritic and inflammatory, dry skin condition with many known comorbidities. These include airway disease, food allergies, atopic eye disease and autoimmune conditions. Furthermore, there is often significant sleep disturbance as well as increased psychological distress and mental health problems. Severe AD therefore often has a significant impact on the quality of life of both patients and their families. In this review we discuss recent findings on the putative links between AD, its association with itch, sleep disturbance and neuropsychiatric morbidity, including the role of inflammation in these conditions. Itch was thought to predominantly drive sleep disruption in AD. We now understand changes in sleep influence immune cell distribution and the associated inflammatory cytokines, which suggests a bidirectional relationship between AD and sleep. We also increasingly recognize inflammation as a key driver in psychological symptoms and disorders. The link between cutaneous, systemic and possible brain inflammation could at least in part be driven by the sleep deprivation and itch-driven neuronal proliferation seen in AD.

Treatment satisfaction of adult patients with moderate-to-severe atopic dermatitis treated with baricitinib in France, Germany, and the United Kingdom: results from a cross-sectional international patient survey

INTRODUCTION

We explored patient satisfaction with baricitinib, an oral Janus kinase inhibitor, in patients with atopic dermatitis (AD) treated in routine clinical practice.

METHODS

Adults with moderate-to-severe AD treated with baricitinib in clinical practice for ≥4 weeks in France, Germany, and the UK completed a one-time online survey under market research methodologies. Treatment satisfaction was assessed using a Likert scale and abbreviated Treatment Satisfaction Questionnaire for Medication (TSQM-9). Patients reported demographic, disease, and treatment information. Data were analyzed descriptively.

RESULTS

The survey was completed by 170 patients with a mean age of 39.3 years (SD = 13.5), 59% (n = 101) were female. At baricitinib initiation, 79% rated their AD as "Severe", yet 28% reported body surface area (BSA) involvement ≥10%. Most were "Satisfied" or "Very satisfied" (76%/18%) with baricitinib, with high rates reported for controlling itch (36%/56%). Itch improvements were noted by 97% of patients. Some tapered/stopped (50%/32%) topical corticosteroid use, aligned with reported improvements on the patient global assessment and BSA. Mean TSQM-9 convenience score was 78.0 (SD = 14.0).

CONCLUSIONS

Satisfaction with itch control was particularly high, reflected in rates of improvement in itch since starting baricitinib. On the TSQM-9, the convenience score was the highest. Many patients tapered/stopped concomitant topicals, indicating baricitinib's effect in controlling AD symptoms.

Automated Machine Learning Analysis of Patients With Chronic Skin Disease Using a Medical Smartphone App: Retrospective Study

BACKGROUND

Rapid digitalization in health care has led to the adoption of digital technologies; however, limited trust in internet-based health decisions and the need for technical personnel hinder the use of smartphones and machine learning applications. To address this, automated machine learning (AutoML) is a promising tool that can empower health care professionals to enhance the effectiveness of mobile health apps.

OBJECTIVE

We used AutoML to analyze data from clinical studies involving patients with chronic hand and/or foot eczema or psoriasis vulgaris who used a smartphone monitoring app. The analysis focused on itching, pain, Dermatology Life Quality Index (DLQI) development, and app use.

METHODS

After extensive data set preparation, which consisted of combining 3 primary data sets by extracting common features and by computing new features, a new pseudonymized secondary data set with a total of 368 patients was created. Next, multiple machine learning classification models were built during AutoML processing, with the most accurate models ultimately selected for further data set analysis.

RESULTS

Itching development for 6 months was accurately modeled using the light gradient boosted trees classifier model (log loss: 0.9302 for validation, 1.0193 for cross-validation, and 0.9167 for holdout). Pain development for 6 months was assessed using the random forest classifier model (log loss: 1.1799 for validation, 1.1561 for cross-validation, and 1.0976 for holdout). Then, the random forest classifier model (log loss: 1.3670 for validation, 1.4354 for cross-validation, and 1.3974 for holdout) was used again to estimate the DLQI development for 6 months. Finally, app use was analyzed using an elastic net blender model (area under the curve: 0.6567 for validation, 0.6207 for cross-validation, and 0.7232 for holdout). Influential feature correlations were identified, including BMI, age, disease activity, DLQI, and Hospital Anxiety and Depression Scale-Anxiety scores at follow-up. App use increased with BMI >35, was less common in patients aged >47 years and those aged 23 to 31 years, and was more common in those with higher disease activity. A Hospital Anxiety and Depression Scale-Anxiety score >8 had a slightly positive effect on app use.

CONCLUSIONS

This study provides valuable insights into the relationship between data characteristics and targeted outcomes in patients with chronic eczema or psoriasis, highlighting the potential of smartphone and AutoML techniques in improving chronic disease management and patient care.

Dupilumab significantly improves sleep in adults with atopic dermatitis: results from the 12-week placebo-controlled period of the 24-week phase IV randomized double-blinded placebo-controlled DUPISTAD study

BACKGROUND

Sleep disturbance is a prominent symptom of atopic dermatitis (AD) and can result in insomnia, daytime fatigue, drowsiness, reduced productivity and impaired quality of life (QoL).

OBJECTIVES

The Dupilumab Effect on Sleep in AD Patients (DUPISTAD) phase IV randomized double-blinded placebo-controlled study evaluated the impact of dupilumab treatment on sleep and other patient- and physician-reported outcomes.

METHODS

Adults with moderate-to-severe AD were randomized 2 : 1 to dupilumab 300 mg once every 2 weeks (q2w) or placebo for 12 weeks; concomitant topical corticosteroids were permitted. Patients subsequently entered an open-label phase and received dupilumab 300 mg q2w for a further 12 weeks. The primary endpoint was the percentage change in sleep quality from baseline to week 12, assessed using a novel numeric rating scale (NRS). Secondary and exploratory endpoints included percentage change in peak pruritus NRS (PP NRS), change in SCORing Atopic Dermatitis (SCORAD), SCORAD sleep visual analogue scale (VAS), Eczema Area and Severity Index, Patient-Reported Outcomes Measurement Information System (PROMIS) sleep-related impairment T-score and the Epworth Sleepiness Scale. Sleep diary and wrist actigraphy measurements were recorded throughout the study.

RESULTS

In total, 127 patients received dupilumab and 61 patients received placebo. Demographic and baseline disease characteristics were balanced between groups. Sleep quality NRS significantly improved in patients treated with dupilumab by week 12 vs. placebo [least squares mean of the difference (LSMD) -15.5%, P < 0.001]. PP NRS (LSMD -27.9%, P < 0.001), SCORAD (LSMD -15.1, P < 0.001), SCORAD sleep VAS (LSMD -2.1, P < 0.001) and PROMIS T-score (LSMD -3.6, P < 0.001) were also significantly improved at week 12 with dupilumab vs. placebo. The overall percentage of patients reporting treatment-emergent adverse events was lower in the dupilumab group (56.7%) than in the placebo group (67.2%).

CONCLUSIONS

Dupilumab significantly improved sleep quality and perception of sleep continuity, itch, metrics of AD severity and QoL in adults with moderate-to-severe AD, with an acceptable safety profile compared with placebo.

Dupilumab Treatment Efficacy and Impact on Clinical Scores, Serum Biomarkers, and Itch in Adult Patients with Atopic Dermatitis: A Retrospective Analysis

Purpose

Dupilumab, a fully human monoclonal antibody that inhibits the signaling pathways of interleukin (IL)-4 and IL-13, has demonstrated remarkable efficacy in the treatment of atopic dermatitis (AD). Dupilumab has been reported to attenuate itch and reduce several serum markers, including blood lactate dehydrogenase (LDH), blood eosinophil count, and serum total immunoglobulin E (IgE).

Patients and Methods

The present study investigated retrospectively changes in clinical scores and serum biomarker from 175 adults with moderate-to-severe AD treated with dupilumab. Clinical manifestations were assessed using eczema area and severity index (EASI) and visual analogue scale (VAS) for itch at baseline and subsequently at 16-week intervals up to a duration of 48 weeks. Total IgE, LDH and blood eosinophil count were also collected.

Results

The dupilumab treatment significantly improved EASI and VAS scores and decreased serum levels of IgE, LDH, and total eosinophil count. The EASI scores were positively correlated with VAS for itch at all recorded time points, whereas serum biomarkers did not exhibit a strong correlation with EASI scores.

Conclusion

These findings highlight the close relationship between the extent and severity of eczema and the intensity of itch experienced by patients and suggest that factors beyond the measured serum biomarkers play a significant role in the clinical manifestations of AD, emphasizing the complex nature of the disease.

Combination treatment of dupilumab with bortezomib in a patient with IgG kappa gammopathy of renal significance, uremic pruritus and chronic lichenoid dermatitis

Chronic pruritus (CP) is one of the most frequent symptoms among dermatological conditions, capable of reducing the quality of life (QoL). CP may be induced by atopic dermatitis or other dermatological and/or non-dermatological conditions. In this article, we report the case of a patient affected by generalized CP, characterised by multiple papulo-nodular and escoriatic lesions, developed after the onset of an immunoglobulin G (IgG) kappa monoclonal gammopathy of renal significance (MGRS), associated with renal insufficiency. Therefore, a combined treatment with dupilumab for CP and bortezomib for the hematologic malignancy was administered to the patient. The present case report highlights the efficacy of dupilumab for the treatment of CP. Moreover, no relevant side effects were recorded during the treatment in combination with other systemic biological drugs for other systemic pathologies.

Itch, sleep loss, depressive symptoms, fatigue, and productivity loss in patients with moderate-to-severe atopic dermatitis: Analyses of TREATgermany registry data

BACKGROUND

TREATgermany is a multicenter registry including patients with moderate-to-severe atopic dermatitis (AD) from currently 74 study centers (university clinics, hospitals and practices) in Germany. As of August 31, 2021, 1,230 adult patients were enrolled.

METHODS

In TREATgermany, patients and physicians fill in questionnaires pertaining to symptoms, disease severity, quality of life, depressiveness, and fatigue. In particular, limitations in work performance are assessed using the Work Limitations Questionnaire (WLQ). To assess associations between occupational performance/work limitations and symptoms, correlations and regression models were calculated.

RESULTS

The examined sample of 228 employed patients reported an average of 6% at-work productivity loss within the past two weeks prior to enrolment in the registry. The WLQ productivity loss score was moderately associated with itch (r = 0.32) and sleep loss (r = 0.39) and strongly associated with depressive symptoms (r = 0.68) and fatigue (r = 0.60).

CONCLUSIONS

The analyses of the registry data show that moderate-to-severe atopic dermatitis has a negative impact on the work productivity of the patients. The analyses further point out the relevant associations between work productivity, depressive symptoms, and fatigue highlighting the disease burden caused by the psychological components of AD.

Juckreiz, Schlafstörungen, depressive Symptome, Fatigue und Einschränkungen der Arbeitsproduktivität bei Patienten mit moderater bis schwerer atopischer Dermatitis: Daten aus dem TREATgermany-Register

Hintergrund

TREATgermany ist ein multizentrisches Register, das Patienten mit moderater bis schwerer atopischer Dermatitis (AD) aus derzeit 74 Studienzentren (Universitätskliniken, Krankenhäuser und Praxen) in Deutschland umfasst. Bis zum 31. August 2021 wurden 1.230 erwachsene Patienten eingeschlossen.

Methoden

In TREATgermany füllen Patienten und Ärzte Fragebögen zu Symptomen, Krankheitsschwere, Lebensqualität, Depressivität und Fatigue aus. Die Einschränkungen der Arbeitsleistung werden insbesondere mit dem Work Limitations Questionnaire (WLQ) erfasst. Um Assoziationen zwischen beruflicher Leistung/Arbeitseinschränkungen und Symptomen zu bestimmen, wurden Korrelationen und Regressionsmodelle berechnet.

Ergebnisse

Die untersuchte Stichprobe von 228 berufstätigen Patienten beschrieb einen durchschnittlichen Produktivitätsverlust von 6% bei der Arbeit innerhalb der letzten zwei Wochen vor der Aufnahme in das Register. Der WLQ‐Wert für den Produktivitätsverlust war moderat mit Juckreiz (r = 0,32) und Schlafstörungen (r = 0,39) und stark mit depressiven Symptomen (r = 0,68) und Fatigue (r = 0,60) korreliert.

Schlussfolgerungen

Die Analysen der Registerdaten zeigen, dass eine moderate bis schwere AD einen negativen Einfluss auf die Arbeitsproduktivität der Patienten hat. Die Analysen weisen außerdem auf die relevanten Zusammenhänge zwischen Arbeitsproduktivität, depressiven Symptomen und Fatigue hin, was die durch die psychologischen Komponenten der AD verursachte Krankheitslast verdeutlicht.

Age-Related Skin Inflammation in A 2,4-Dintrochlorobenzene-Induced Atopic Dermatitis Mouse Model

One of the most affected aspects of the aging process is immunity, with age-related immune system decline being responsible for an increase in susceptibility to infectious diseases and cancer risk. On the other hand, the aging process is accompanied with low-grade pro-inflammatory status. This condition involves a persistent rise in cytokine levels that can activate both innate and adaptive immune systems. Finally, despite the fact that immunological responses to antigenic stimulations decrease with age, the incidence and prevalence of many common autoimmune diseases increase in the elderly population. Overall, the co-existence of a prolonged, low-grade inflammatory status and declining immune activity appears to be a paradoxical phenomenon. This study characterized skin inflammation in mouse dermatitis model of various ages to monitor possible changes of inflammatory responses during aging.

Clinical trials of antibody drugs in the treatments of atopic dermatitis

Atopic dermatitis (AD) is one of the most common, relapsing, chronic inflammatory skin disease, being regarded as a global health issue. Recent studies have shown that Th2 cell-mediated type 2 immunity plays a central role in AD. The type 2 inflammatory cytokines such as IL-4, IL-13, IL-22, IL-31, IL-17 and IL-5 mediate the pathogenesis of AD. A variety of antibody drugs targeting these cytokines have been developed to treat AD in clinics. Notably, several antibody drugs have exhibited high efficacy in treating atopic dermatitis in previous studies, demonstrating that they could be therapeutic methods for AD patients. Herein, we reviewed the clinical trials of antibody drugs in the treatment of AD, which provides a useful guideline for clinicians to treat patients with AD in clinics.

Association between atopic dermatitis and school readiness in preschool children

BACKGROUND

Although atopic dermatitis (AD) in children affects diverse stages of life, no studies have reported on the association between school readiness and AD.

METHODS

This study used Korean National Health Insurance data and the Health Screening Program for Infants and Children. Among all children born between 2008 and 2012 in Korea, those who were assessed for school readiness through questionnaires in a health screening program performed at 54 and 60 months old were enrolled. AD was defined based on the International Classification of Diseases codes, with two or more prescriptions of topical corticosteroids during the first 54-60 months of life. The primary outcome was the association between school readiness and AD. The questionnaire relating to school readiness comprised six items - cognitive skills, social development, activeness, concentration, emotional development, and language skills. Logistic regression analysis was used to identify the associations between school readiness and AD.

RESULTS

This study included 239,673 children without AD and 38,229 children with AD. The average age at which school readiness was assessed was 4.8 years. AD was associated with vulnerability in activeness (adjusted odds ratio: 1.127; 95% confidence interval: 1.071-1.186) and concentrations (1.170; 1.093-1.254). The impact of AD on concentrations showed consistent results regardless of sex, exposure to systemic corticosteroids and antihistamines, and age at the diagnosis of AD.

CONCLUSIONS

Children with AD have vulnerability in school readiness in the aspects of activeness and concentration.

Adriforant is a functional antagonist of histamine receptor 4 and attenuates itch and skin inflammation in mice

BACKGROUND

Histamine has been postulated to play a role in atopic dermatitis via histamine receptor 4, mediating pruritic and inflammatory effects. The H4R antagonist adriforant (PF-3893787 or ZPL389) indicated clinical efficacy in a Ph2a study in atopic dermatitis. Preclinical investigations of adriforant had been scarce as experiments in transfectants with H4R from several species suggested partial agonism, not seen in human cells.

OBJECTIVE

During the Ph2b trial in AD, we performed experiments to understand the pharmacology of adriforant in primary murine cells and in vivo models. We assessed its effects on ERK phosphorylation and transcriptional changes in bone marrow-derived mast cells, histamine-dependent Ca²⁺ flux in neurons and histamine-induced itch response. In addition, its impact on MC903-induced skin inflammation was evaluated.

RESULTS

We show that, contrary to transfectants, adriforant is a competitive antagonist of the murine histamine receptor 4, antagonizes histamine-induced ERK phosphorylation, normalizes histamine-induced transcriptional changes in mast cells and reduces histamine-dependent Ca²⁺ flux in neurons. Administration to mice reduces acute histamine-induced itch response. In addition, adriforant ameliorates inflammation in the mouse MC903 model.

CONCLUSIONS

Our results suggest that functional inhibition of histamine receptor 4 by adriforant reduces itch and inflammation in vivo. The effects observed in mice, however, did not translate to clinical efficacy in patients as the Ph2b clinical trial with adriforant did not meet pre-specified efficacy endpoints. Given the complex pathogenesis of AD, antagonism of histamine receptor 4 alone appears insufficient to reduce disease severity in AD patients, despite the effects seen in mouse models.

Nemolizumab Improves Patient-Reported Symptoms of Atopic Dermatitis with Pruritus: Post Hoc Analysis of a Japanese Phase III Randomized Controlled Trial

INTRODUCTION

Atopic dermatitis (AD), with its signs and symptoms of pruritus, dryness, and erythema, severely reduces the quality of life (QOL) of affected patients. We investigated the impact of nemolizumab 60 mg on QOL in Japanese patients aged ≥ 13 years with AD and inadequately controlled moderate-to-severe pruritus, using data derived from patient-reported outcome (PRO) measures.

METHODS

PROs were the Insomnia Severity Index (ISI), Dermatology Life Quality Index (DLQI), Patient-Oriented Eczema Measure (POEM), and Work Productivity and Activity Impairment: Atopic Dermatitis questionnaire (WPAI-AD). Correlations between PRO scores and symptom severity, assessed by the pruritus visual analog scale (VAS) and the Eczema Area and Severity Index (EASI), were explored.

RESULTS

The mean percent change (standard error) from baseline in the pruritus VAS and EASI scores at week 16 was, respectively, -45.6% (2.7) and -46.0% (3.2) in the nemolizumab group, and -24.1% (3.7) and -33.2% (4.9) in the placebo group. By week 16, significantly more patients in the nemolizumab group versus the placebo group had an ISI score of 0 for difficulty falling asleep (41.6% versus 13.1%, nominal p < 0.01) or difficulty staying asleep (45.4% versus 10.9%; nominal p < 0.01). Similarly, more nemolizumab- than placebo-treated patients had a DLQI score of 0 for interference with shopping, or home/garden activities (45.2% versus 18.6%, nominal p < 0.01), and 0 days per week of nighttime sleep disturbance (50.8% versus 16.9%, nominal p < 0.01) or bleeding skin (43.4% versus 7.5%, nominal p < 0.01) measured by POEM at week 16. Based on WPAI-AD scores, long-term administration of nemolizumab also improved the ability to conduct work activities.

CONCLUSIONS

Subcutaneous administration of nemolizumab ameliorated pruritus and skin signs, and thereby produced improvement in patient QOL across multiple PRO measures, including sleep, interpersonal relationships, and the ability to conduct social or work activities.

CLINICAL TRIAL REGISTRATION

JapicCTI-173740 (registered 20 October 2017).

Pruritogenic Mediators and New Antipruritic Drugs in Atopic Dermatitis

Atopic dermatitis (AD) is a common highly pruritic chronic inflammatory skin disorder affecting 5-20% of children worldwide, while the prevalence in adults varies from 7 to 10%. Patients with AD experience intense pruritus that could lead to sleep disturbance and impaired quality of life. Here, we analyze the pathophysiology of itchiness in AD. We extensively review the histamine-dependent and histamine-independent pruritogens. Several receptors, substance P, secreted molecules, chemokines, and cytokines are involved as mediators in chronic itch. We also, summarize the new emerging antipruritic drugs in atopic dermatitis.

Burden of Disease and Unmet Needs in Atopic Dermatitis: Results From a Patient Survey

Background: Atopic dermatitis (AD) affects 2%-10% of adults worldwide. Occurrence and severity of symptoms and treatment success vary among patients. Objective: To determine disease severity, burden, and treatment use and satisfaction in adults with AD. Methods: An international internet-based survey was conducted (October 5-November 1, 2021) in participants with AD from Canada, France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States. Results: Of 2005 AD patients surveyed, 92% had body surface area (BSA) involvement <10%. Itch was the most bothersome symptom; 48.5% of participants reported severe itch in the past week (Itch Numerical Rating Scale [NRS] 7-10; 45.9% for BSA <10%, 75.0% for BSA ≥10%). Most participants reported moderate or severe sleep disturbance in the past week (Sleep NRS 4-10; 67.1% for BSA <10%, 92.3% for BSA ≥10%). Itch was the top reason for participants' most recent health care provider visit; reducing itching was their top treatment goal. Topical therapies, which were most commonly used, resulted in low treatment satisfaction. Conclusions: Itch was the most bothersome AD symptom. Although clinical development has focused on improving skin lesions, improving itch is patients' top treatment goal. This survey highlights the need for systemic antipruritic therapies that could reduce itch in nonlesional and lesional skin.

Clinically meaningful improvements in cutaneous lesions and quality of life measures in patients with atopic dermatitis with greater pruritus reductions after treatment with 60 mg nemolizumab subcutaneously every 4 weeks: Subgroup analysis from a phase 3, randomized, controlled trial

BACKGROUND

Data from the Japanese phase 3 Nemolizumab-JP01 study (JapicCTI-173740) found that nemolizumab in combination with topical treatments reduced pruritus associated with atopic dermatitis inadequately controlled with current therapies.

METHODS

This post-hoc analysis examined associations between improvements in pruritus (visual analog scale [VAS]) and eczema (Eczema Area and Severity Index [EASI]), and achievement of other clinically relevant endpoints including the Insomnia Severity Index (ISI), Dermatology Life Quality Index (DLQI), and Patient-Oriented Eczema Measure (POEM).

RESULTS

Pruritus VAS responders (≥50% improvement from baseline to week 16) showed greater improvements from baseline in these additional endpoints as early as week 1, compared with non-responders. Responders also had EASI improvement, and more than 80% achieved an ISI score ≤7, or had improvement in the DLQI or POEM. The percent change from baseline in VAS and EASI scores at week 16 was in favor of nemolizumab in all subgroups based on baseline characteristics. No specific factor affecting treatment response to nemolizumab was identified.

CONCLUSIONS

In this post-hoc analysis, nemolizumab-treated patients who had greater pruritus reductions also showed improvements in other eczema symptoms; pruritus alleviation appeared to be responsible for the improvements in eczema, sleep and daily life.

Pruritogens in pemphigoid diseases: Possible therapeutic targets for a burdensome symptom

Pruritus is a hallmark feature in pemphigoid diseases, where it can be severe and greatly impact the quality of life of affected patients. Despite being a key symptom, the exact pathophysiological mechanisms involved in pruritus in pemphigoid are yet to be fully elucidated and effective therapies addressing them are limited. This review summarizes the present understanding of pruritus specific to pemphigoid diseases, especially the pruritogens that induce it, and the therapeutic options that have been explored so far. The majority of the available evidence is on bullous pemphigoid and epidermolysis bullosa acquisita. Histamine derived from basophils correlates with pruritus severity, with omalizumab demonstrating promising efficacy in pruritus for bullous pemphigoid. IL-4/-13 contribute to itch in bullous pemphigoid with dupilumab being evaluated in clinical trials. Other pruritogens of interest include substance P, tryptase, and thymic stromal lymphopoetin, with therapies targeting them requiring further investigation. Scratching behaviors contribute directly to blister formation through various mechanisms, such as pathological autoantibody recruitment, T helper cell type 1 polarization, and exposure of intracellular autoantigens. Treatments addressing these pathways may contribute to decreasing disease severity. Additional studies are needed to fully characterize how pruritus is regulated in pemphigoid diseases, to help pave the way to develop novel and effective therapeutics that will not only address pruritic symptoms but also decrease disease severity.

How Does Botulinum Toxin Inhibit Itch?

Two decades after reports of the anti-pruritic effects of botulinum neurotoxins (BoNTs), there is still no approved product for the anti-itch indication of BoNTs, and most clinical case reports still focus on the off-label use of BoNTs for various itchy conditions. Few randomized clinical trials have been conducted with controversial results, and the beneficial effects of BoNTs against itch are mainly based on case studies and case series. These studies are valuable in presenting the potential application of BoNTs in chronic pruritic conditions, but due to the nature of these studies, they are categorized as providing lower levels of evidence or lower grades of recommendation. To obtain approval for the anti-pruritic indication of BoNTs, higher levels of evidence are required, which can be achieved through conducting large-scale and well-designed studies with proper control groups and established careful and reliable primary and secondary outcomes. In addition to clinical evidence, presenting the mechanism-based antipruritic action of BoNTs can potentially strengthen, accelerate, and facilitate the current efforts towards further investments in accelerating the field towards the potential approval of BoNTs for itchy conditions. This review, therefore, aimed to provide the state-of-the-art mechanisms underlying the anti-itch effect of BoNTs from basic studies that resemble various clinical conditions with itch as a hallmark. Evidence of the neuronal, glial, and immune modulatory actions of BoNTs in reducing the transmission of itch are presented, and future potential directions are outlined.

Pruritus bei atopischer Dermatitis – vergleichende Bewertung neuer Therapieansätze

Chronischer Pruritus (Dauer ≥ 6 Wochen) betrifft ca. 91 % der Patienten mit atopischer Dermatitis (AD). Neben reinem Jucken werden häufig Begleitsensationen wie Schmerzen, Brennen, Stechen und Hitzegefühl berichtet. Der Leidensdruck betroffener Patienten ist dadurch hoch; Schlaf und Lebensqualität können stark beeinträchtigt sein. Im Fokus der Behandlung der AD steht daher auch die suffiziente Kontrolle des Pruritus. Neben einer intensiven rückfettenden Basispflege können topisch Kortikosteroide und Calcineurininhibitoren angewendet werden. Bei ausgeprägtem Hautbefund kann Phototherapie zur Abheilung von Ekzemen und Linderung des atopischen Pruritus beitragen. Im Hinblick auf Systemtherapien stehen mehrere zugelassene Biologika (Dupilumab, Tralokinumab) und Januskinase-Inhibitoren (Baricitinib, Upadacitinib, Abrocitinib) zur Verfügung, die über die Interferenz mit der Signaltransduktion proinflammatorischer Zytokine zu einer raschen Pruritusreduktion führen. Während Januskinase-Inhibitoren zu einer initial schnelleren Prurituslinderung führen, scheinen sich Biologika und Januskinase-Inhibitoren mit zunehmender Therapiedauer hinsichtlich ihrer antipruritischen Wirksamkeit anzugleichen.

Pharmacokinetics, Safety, Efficacy, and Biomarker Profiles During Nemolizumab Treatment of Atopic Dermatitis in Adolescents

Introduction

Nemolizumab, a new monoclonal antibody that targets the receptor alpha of the neuroimmune cytokine interleukin-31 (IL-31), has shown efficacy in atopic dermatitis (AD) in adults. This study evaluated the pharmacokinetics (PK) and safety of nemolizumab in adolescents with moderate to severe AD as well as the relationship between nemolizumab concentrations and clinical efficacy and the effect of nemolizumab on protein biomarkers.

Methods

Open-label, 16-week study of nemolizumab in patients aged 12–17 years with moderate to severe AD (baseline EASI ≥ 16, IGA ≥ 3, and BSA ≥ 10%) and associated pruritus with baseline average daily peak pruritus numeric rating scale (PP-NRS) intensity of at least 4. Nemolizumab was administered subcutaneously as a loading dose of 60 mg at baseline, followed by 30 mg every 4 weeks until week 12 with background topical corticosteroids (TCS) or calcineurin inhibitors (TCI). Subsequently patients were followed for 8 weeks more. Stratum corneum (SC) and plasma samples were collected for biomarker assessments.

Results

Twenty patients participated, with a mean age of 14.8 ± 1.6 years. The PK of nemolizumab was described by a one-compartment model with linear elimination, a first-order absorption, and a mean half-life of 16.7 ± 4.1 days. Mean trough concentrations ranged from 2935 ± 1029 ng/mL to 3292 ± 2018 ng/mL over the 16-week treatment period. There was a marked improvement in rash, itch, and sleep with a decrease from baseline to week 16 in EASI by 66.5 ± 32.5%, in PP-NRS by 43.2 ± 37%, and in sleep disturbance numeric rating scale by 53.5 ± 47.8%. The popPK and PK/PD analyses confirmed that model-predicted exposure and efficacy of nemolizumab were similar in adolescents compared to adults receiving the same dosing regimens. Age did not impact PK parameters, while the main source of PK variability was body weight. Analyses of SC samples identified a panel of AD-related pro-inflammatory biomarkers that were upregulated in lesional skin (compared to non-lesional skin) and correspondingly downregulated in clinical responders to nemolizumab (based on EASI75 and PP-NRS ≥ 4). Four biomarkers (CCL20, CCL22, CCL27, and VEGF) had changes that were 1.9–3.5-fold higher in EASI responders than in EASI non-responders (all p < 0.05). Analysis showed no significant correlation between plasma biomarkers and clinical scores. Adverse events were experienced by 33.3% of subjects (n = 6) and were primarily mild or moderate in severity.

Conclusions

Nemolizumab PK and safety profiles in adolescents with moderate to severe AD are consistent with previous nemolizumab studies in adults. PK/PD models demonstrate similar exposure–response profiles in 12- to 17-year-old adolescents and adults for three clinical endpoints (EASI, IGA, and PP-NRS). Nemolizumab treatment reversed AD-related pro-inflammatory biomarkers in skin, indicating that the neuroimmune cytokine IL-31 is an important mediator of multiple pathways in AD.

Clinical Trial Registration

Clinicaltrials.gov NCT03921411.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-021-00678-7.

Characteristics, mechanism, and management of pain in atopic dermatitis: A literature review

Background

Atopic dermatitis (AD) is a chronic, pruritic, immune‐mediated inflammatory disease. Developments in basic science and clinical research have increased our understanding of AD. Although pain as a symptom of AD is underemphasized in previous studies, multiple researchers address pain as a frequent burden of AD. However, the exact role of pain in AD is not fully understood.

Aims

Our review aimed to summarize the current evidence focusing on characteristics, mechanism, and management of pain in AD.

Materials & Methods

We conducted a thorough literature review in the PubMed database to figure out different aspects discussing pain in AD, including pain symptoms, burden, the relationship between pain and itch, mechanism, and pain management in AD.

Results and Conclusion

AD patients affected by skin pain vary from 42.7%‐92.2% with remarkable intensity and heavy burden. Skin pain and itch interacted both in symptoms and mechanisms. Atopic skin with the impaired barrier, neurogenic inflammation mediators, peripheral and central sensitization of pain may possibly explain pain mechanism in AD. Future research is needed to clarify the commonality and disparity of pain and itch in AD in order to seek efficacious medications and treatment.

Osthole Inhibits Expression of Genes Associated with Toll-like Receptor 2 Signaling Pathway in an Organotypic 3D Skin Model of Human Epidermis with Atopic Dermatitis

The Toll-like receptor (TLR) family signature has been linked to the etiopathology of atopic dermatitis (AD), a chronic inflammatory skin disease associated with skin barrier dysfunction and immune system imbalance. We aimed to investigate whether osthole (a plant-derived compound) can inhibit the genetic profile of key genes associated with TLR2 signaling (TIRAP, MyD88, IRAK1, TRAF6, IκBα, NFκB) after stimulation with LPS or histamine in a 3D in vitro model of AD. Overexpression of the aforementioned genes may directly increase the secretion of proinflammatory cytokines (CKs) and chemokines (ChKs), which may exacerbate the symptoms of AD. Relative gene expressions were quantified by qPCR and secretion of CKs and ChKs was evaluated by ELISA assay. LPS and histamine increased the relative expression of genes related to the TLR2 pathway, and osthole successfully reduced it. In summary, our results show that osthole inhibits the expression of genes associated with the TLR signaling pathway in a skin model of AD. Moreover, the secretion of CKs and ChKs after treatment of AD with osthole in a 3D skin model in vitro suggests the potential of osthole as a novel compound for the treatment of AD.

Itch in Hymenoptera Sting Reactions

Insect stings and the resulting itch are a ubiquitous problem. Stings by members of the insect order Hymenoptera, which includes sawflies, wasps, bees and ants, and especially by bees and wasps are extremely common, with 56–94% of the population being stung at least once in their lifetime. The complex process of venom activity and inflammation causes local reactions with pain and pruritus, sometimes anaphylactic reactions and more seldomly, as in case of numerous stings, systemic intoxication. We reviewed the literature regarding itch experienced after Hymenoptera stings, but found no study that placed a specific focus on this topic. Hymenoptera venoms are composed of many biologically active substances, including peptide toxins and proteinaceous toxins. Peptide toxins from bee venom cause cell lysis and ion channel modulation in the peripheral and central nervous systems, while toxins from wasp venom induce mast cell degranulation and chemotaxis of polymorphonuclear leukocytes in the skin. The proteinaceous toxins cause a disruption of the cell membranes and necrotic cell death, degradation of hyaluronan (an extracellular matrix glycosaminoglycan), increased vascular permeability, hemolysis, as well as activated platelet aggregation. Mediators which could be directly involved in the venom-induced pruritus include histamine and tryptase released from mast cells, interleukin-4 and interleukin-13 from Th2 lymphocytes, as well as leukotriene C4. We postulate that a pruriceptive itch is induced due to the pharmacological properties of Hymenoptera venoms.

Cera Flava Alleviates Atopic Dermatitis by Activating Skin Barrier Function via Immune Regulation

Cera Flava (CF), a natural extract obtained from beehives, is widely used in dermatological products owing to its wound healing, wrinkle reduction, UV-protective, and skin cell turnover stimulation effects. However, its effect on AD-like skin lesions is unknown. In this study, we used a mouse model of AD to evaluate the effects of CP at the molecular and phenotypic levels. Topical house dust mite (HDM) sensitization and challenge were performed on the dorsal skin of NC/Nga mice to induce AD-like cutaneous lesions, phenotypes, and immunologic responses. The topical application of CF for 6 weeks relieved HDM-induced AD-like phenotypes, as quantified by the dermatitis severity score, scratching frequency, and skin moisture. CP decreased immunoglobulin E, histamine, and thymic stromal lymphopoietin levels. Histopathological analysis showed that CF decreased epidermal thickening and the number of mast cells. CF attenuated HDM-induced changes in the expression of skin barrier-related proteins. Furthermore, CF decreased the mRNA levels of inflammatory factors, including interleukin (IL)-1β, IL-4, IL-13, IL-8, TARC, MDC, and RANTES, in dorsal skin tissue via the TLR2/MyD88/TRAF6/ERK pathway. CF influences skin barrier function and immune regulation to alleviate AD symptoms. It may therefore be an effective alternative to topical steroids for the treatment of AD.