Management of Itch in Atopic Dermatitis

["Red flags" during pregnancy-skin symptoms and their causes during pregnancy]

Pregnancy is a special state for the expectant mother. Not only is a human being growing, but the pregnant woman's body is also constantly changing during the 40-week pregnancy. One organ that is frequently affected by these changes is the skin. As diagnosis and treatment during pregnancy can present treating physicians with particular challenges, it is important to know the relevant pregnancy dermatoses, to recognize and diagnose them reliably, and to observe red flags in order to protect the pregnant women and the unborn child. In this article, the most important changes in the skin of pregnant patients are explained and potential warning signs are presented. In addition to aspects of altered pigmentation, the influence of pregnancy on pre-existing inflammatory dermatoses and their improvement or worsening is also described. The occurrence of so-called specific pregnancy dermatoses over the course of pregnancy is also explained. Finally, the extent to which autoimmune diseases of the mother can also affect the unborn child and to what extent skin changes in the newborn can indicate a disease of the mother are described. The respective "red flags" are presented as leading symptoms and their relevance is discussed.

Combination of a Topical Anti-Inflammatory Drug and a Moisturizer, Both with a Lamellar Structure Containing Synthetic Pseudo-Ceramides, for the Treatment of Patients with Mild-to-Moderate Atopic Dermatitis

Purpose

Atopic dermatitis is characterized by chronic inflammation and dryness accompanied by severe itching. The combined use of moisturizers and topical anti-inflammatory drugs is essential for alleviating atopic dermatitis. We have developed a topical anti-inflammatory drug with a steroid and a moisturizer with heparinoid, both in lamellar structure-based formulations containing synthetic pseudo-ceramides. Here, assessed the efficacy of this combination in the treatment of atopic dermatitis.

Methods

We included 22 patients with mild to moderate atopic dermatitis and subjected them to a seven-week treatment with the test formulations, followed by a four-week post-treatment period.

Results

Clinical findings and the quality of life of participants remarkably improved after one week of treatment. Furthermore, skin hydration and transepidermal water loss considerably improved at weeks one and three, respectively. The Cer [NP]/[NS] ratio, an indicator of epidermal turnover, substantially increased during the treatment period and remained elevated even thereafter. The improvement in stratum corneum function was distinctive in participants with lower barrier function.

Conclusion

These findings indicated that the combined use of the anti-inflammatory drug and moisturizer, both in lamellar structure-based formulations, is effective in treating atopic dermatitis in patients with fragile barrier function.

Exploring the Metabolic Effects of a Herbal Remedy of Asarum sieboldii, Platycodon grandiflorum, and Cinnamomum cassia Extracts: Unraveling Its Therapeutic Potential as a Topical Application for Atopic Dermatitis Treatment

Our previous study demonstrated that our novel herbal remedy, a mixture of Asarum sieboldii, Platycodon grandiflorum, and Cinnamomum Cassia extracts, exhibits a therapeutic effect in 1-chloro-2,4-dinitrobenzene (DNCB)-induced mice by inhibiting the Th-2 inflammatory response upon oral administration. It also ameliorated imbalances in lipid metabolism related to the skin barrier function in keratinocytes, indicating its potential as a topical agent. This study aims to further investigate the therapeutic effects and metabolic mechanisms of its topical application. The anti-atopic effect was evaluated using dermatitis scores, histopathological analysis, and immune cell factors in DNCB-induced mice. Metabolomic profiling of serum and lesional skin was conducted to elucidate the metabolic mechanisms. The topical application significantly reduced dermatitis scores, mast cell infiltration, and serum levels of immunoglobulin E (IgE), IFN-γ, interleukin (IL)-4, IL-17, and thymic stromal lymphopoietin (TSLP), demonstrating its effectiveness in treating atopic dermatitis (AD). Serum metabolomics revealed alterations in fatty acid metabolism related to the pro-inflammatory response. In lesional skin, metabolic markers associated with oxidative stress, immune regulation, and AD symptoms were restored. This study demonstrated its potential as a topical agent in suppressing Th-2 inflammatory responses and improving metabolic abnormalities related to AD symptoms, providing crucial insights for developing natural AD treatments.

Current and emerging drugs for the treatment of pruritus: an update of the literature

INTRODUCTION

Pruritus, particularly in its chronic form, often imposes significant suffering and reductions in patients' quality of life. The pathophysiology of itch is varied depending on disease context, creating opportunities for unique drug development and multimodal therapy.

AREAS COVERED

The purpose of this article is to provide an update of the literature regarding current and emerging therapeutics in itch. We review the multitudes of drug targets available and corresponding drugs that have shown efficacy in clinical trials, with a particular emphasis on phase 2 and 3 trials and beyond. Broadly, these targets include therapies directed against type 2 inflammation (i.e. Th2 cytokines, JAK/STAT, lipid mediators, T-cell mediators, and other enzymes and receptors) and neural receptors and targets (i.e. PARs, TRP channels, opioid receptors, MRGPRs, GABA receptors, and cannabinoid receptors).

EXPERT OPINION

Therapeutics for itch are emerging at a remarkable pace, and we are entering an era with more and more specialized therapies. Increasingly, these treatments are able to relieve itch beyond their effect on inflammation by directly targeting the neurosensory system.

Relation Between Reactive Oxygen Species Production and Transient Receptor Potential Vanilloid1 Expression in Human Skin During Aging

Skin sensitivity and impaired epidermal barrier function are associated with aging and are at least partly due to increased production of reactive oxygen species (ROS). Transient receptor potential vanilloid1 (TRPV1) is expressed in keratinocytes, fibroblasts, mast cells, and endothelial cells in skin. We investigated in skin biopsies of adult and elderly donors whether TRPV1 expression is involved in the skin aging process. We found that aging skin showed a strongly reduced epidermal thickness, strongly increased oxidative stress, protease expression, and mast cell degranulation and strongly increased TRPV1 expression both in epidermis and dermis. Based on our findings, the aging-related changes observed in the epidermis of the skin level are associated with increased ROS production, and hypothesized alterations in TRPV1 expression are mechanistically linked to this process.

Effects of Magnoliae Flos on Atopic Dermatitis-Like Inflammation Evaluated via Extracellular Signal-regulated Kinase or Signal Transducers and Activators of Transcription 1/3 Signalling Pathways

Atopic dermatitis is a chronic inflammatory skin  disease. Skin is the largest organ and plays a pivotal role in protecting the body. Not only does the skin act as a physical barrier against the external environment, but it also has its own immune system. Atopic dermatitis is caused by prolonged excessive inflammatory responses that worsen under imbalanced cutaneous immune system skin conditions. Although the prevalence and burden of atopic dermatitis is increasing, the standard therapeutic agents remain unclear due to  the complicated pathophysiology of the condition. The objective of this study is to examine the use of Magnoliae flos, the dried flower bud of Magnolia biondii or  related plants. The effects and underlying mechanism of  action of aqueous extract of the buds of Magnoliae flos (MF) were evaluated. Immortalized human keratinocytes (HaCaT) stimulated with tumour necrosis factor-α and interferon-γ mixture and NC/Nga mice stimulated with 2,4-dinitrochlorobenzene were used as atopic dermatitis models, in vitro and in vivo, respectively. The effects of MF were determined by measuring the suppression of pro-inflammatory signalling pathways, such as extracellular signal-regulated kinase or signal transducers and activators of transcription 1/3 and restoring skin barrier molecules. In conclusion, MF is a potential therapeutic alternative for the treatment of atopic dermatitis through repressing inflammatory pathways.

Psychological Stress and Atopic Dermatitis: A Focus Group Study

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disorder. It is often reported to be worsened by psychological stress.

OBJECTIVE

To explore the role of psychological stress and related triggers in AD, and its connection to worsening of this disease, focusing on patients' perspectives.

METHODS

In total, 28 patients with AD were included in focus groups. Topics regarding psychological stress and psychological triggers were discussed.

RESULTS

The hypothesis that psychological stress may have impact on eczema and its pruritus was supported by all of the patients. Distinguishing the worsening effect of psychological stress from effects of physiological triggers, such as infection, climate and allergic factors, was claimed to be difficult by many patients. Most of the patients thought that chronic stress affected the AD more when compared to acute stress. Family problems, financial problems, work overload, school exam periods, lack of structure at work, and unforeseen events were identified as important psychological triggers. Conventional treatment/therapy with topical corticosteroids and emollients, UV light treatment, were suggested as possible treatments, as well as psychological intervention and physical exercise.

CONCLUSION

Psychological stress is an important factor to consider in the management of patients with AD. In particular, chronic stress tends to worsen AD. The type of stress can possibly also affect the quality of the pruritus experienced by the patients. Unforeseen events and decision making were frequently mentioned as important triggers. Furthermore, physical exercise was reported to provide beneficial effects.

Oral difelikefalin reduces moderate to severe pruritus and expression of pruritic and inflammatory biomarkers in subjects with atopic dermatitis

BACKGROUND

Pruritus is the most common and burdensome symptom of atopic dermatitis (AD). Pruritus-targeted treatments in AD are lacking, particularly for patients with milder skin disease.

OBJECTIVE

We sought to evaluate the impact of the selective κ-opioid receptor agonist difelikefalin (DFK) on pruritus intensity and pruritus- and immune-related biomarkers in subjects with moderate to severe AD-related pruritus.

METHODS

A phase 2 clinical trial investigated the efficacy and safety of oral DFK 0.25, 0.5, and 1.0 mg in subjects with moderate to severe AD-related pruritus. A biomarker substudy evaluated the effects of DFK on the expression of pruritus, TH2-associated genes, and skin barrier-related genes.

RESULTS

In the clinical trial (N = 401), all DFK doses reduced itch versus placebo; however, the results were not statistically significant at week 12. In a subgroup of subjects in the trial with mild to moderate skin inflammation and moderate to severe itch (itch-dominant AD phenotype), DFK reduced itch at week 12 versus placebo. In the biomarker substudy, DFK downregulated the expression of key pruritus-related genes (eg, IL-31 and TRPV1) and the AD phenotype (eg, CCL17). Gene set variation analysis confirmed that DFK, but not placebo, downregulated pruritus-related genes and TH2 pathways. DFK improved skin barrier integrity markers and upregulated the expression of claudins and lipid metabolism-associated genes (eg, SEC14L6, ELOVL3, CYP1A2, and AKR1D1).

CONCLUSIONS

DFK treatment reduced itch in subjects with moderate to severe AD-related pruritus, particularly those with an "itch-dominant" AD phenotype, and had an impact on the expression of pruritus, TH2-associated genes, and skin barrier-related genes. DFK is a promising therapy for AD-related pruritus; further clinical studies are warranted.

Kappa opioid agonists in the treatment of itch: just scratching the surface?

Chronic pruritus is a debilitating condition affecting 23-44 million Americans. Recently, kappa opioid agonists (KOAs) have emerged as a novel class of potent antipruritic agents. In 2021, the Food and Drug Administration approved difelikefalin (Korsuva) for the treatment of moderate-to-severe pruritus associated with chronic kidney disease in adults undergoing hemodialysis. Difelikefalin is a potent, peripherally restricted KOA that is intravenously available. Although promising, difelikefalin is currently available as an intravenous composition only, limiting the scope of use. Oral formulations of difelikefalin did not meet the primary endpoint criteria in recent phase 2 clinical trials; however, additional clinical studies are ongoing. The future for KOAs in the treatment of pruritus is encouraging. Orally active pathway-biased KOAs, such as triazole 1.1, may serve as viable alternatives with broader applications. Extended-release compositions, such as the TP-2021 ProNeura subdermal implant, may circumvent the pharmacokinetic issues associated with peptide-based KOAs. Lastly, dual-acting kappa opioid receptor agonist/mu opioid receptor antagonists are orally bioavailable and may be useful in the treatment of various forms of chronic itch. In this review, we summarize the results of KOAs in clinical and preclinical trials and discuss future directions of drug development.

Inhibitory effect of Sanguisorba hakusanensis Makino ethanol extract on atopic dermatitis-like responses in NC/Nga mice and human keratinocytes

Atopic dermatitis (AD) is an allergic, inflammatory skin disease caused by immune dysregulation. In this study, we investigated anti-atopic and anti-inflammatory activities of Sanguisorba hakusanensis ethanol extract (SHE) both in vivo using NC/Nga mice and in vitro using human HaCaT keratinocytes. Oral administration of SHE suppressed several atopic symptoms associated with house dust mites (induced with Dermatophagoides farinae extract) in NC/Nga mice and decreased serum levels of inflammatory mediators such as immunoglobulin E, histamine, and inflammatory chemokines. Additionally, SHE treatment reduced the infiltration of immune cells such as mast cells and macrophages in AD skin lesions. In vitro, interferon-γ- and tumor necrosis factor-α-stimulated HaCaT cells exhibited increased expression of T helper 1 and 2 chemokines; their expression was inhibited by SHE treatment. The anti-inflammatory effects of SHE treatment involved blocking of the mitogen-activated protein kinase and signal transducer and activator of transcription 1 signaling pathways. In conclusion, SHE exerts potent anti-atopic and anti-inflammatory effects and should be considered for the clinical treatment of AD.

Fructo-oligofructose ameliorates 2,4-dinitrofluorobenzene-induced atopic dermatitis-like skin lesions and psychiatric comorbidities in mice

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by pruritus and eczema lesions and psychiatric comorbidities. The gut-brain-skin axis plays a pivotal role during AD development, which might suggest a novel therapeutic strategy for AD. The present study aims to uncover the protective effects and underlying mechanisms of fructo-oligofructose (FOS), a type of prebiotic, on AD-like skin manifestations and comorbid anxiety and depression in AD mice.

RESULTS

Female Kunming mice were treated topically with 2,4-dinitrofluorobenzene (DNFB) to induce AD-like symptoms and FOS was administered daily for 14 days. The results showed that FOS could alleviate AD-like skin lesions markedly as evidenced by dramatic decreases in severity score, scratching bouts, the levels of immunoglobulin E (IgE) and T helper 1(Th1)/Th2-related cytokines, and the infiltration of inflammatory cells and mast cells to the dermal tissues. The comorbid anxiety and depressive-like behaviors, estimated by the forced swimming test (FST), the tail-suspension test (TST), the open-field test (OFT), and the zero maze test (ZMT) in AD mice, were significantly attenuated by FOS. Fructo-oligofructose significantly upregulated brain neurotransmitters levels of 5-hydroxytryptamine (5-HT) and dopamine (DA). Furthermore, FOS treatment increased the relative abundance of gut microbiota, such as Prevotella and Lactobacillus and the concentrations of short-chain fatty acids (SCFAs), especially acetate and iso-butyrate in the feces of AD mice. The correlation analysis indicated that the reshaped gut microbiome composition and enhanced SCFAs formation are associated with skin inflammation and behavioral alteration.

CONCLUSION

Collectively, these data identify FOS as a promising microbiota-targeted treatment for AD-like skin inflammation and comorbid anxiety and depressive-like behaviors. © 2023 Society of Chemical Industry.

Baseline Body Surface Area and Itch Severity Define Response to Baricitinib in Patients with Moderate-to-Severe Atopic Dermatitis at Week 16

INTRODUCTION

Atopic dermatitis (AD) is a chronic, inflammatory skin disease characterized by heterogeneous clinical phenotypes and high symptom burden, especially through itch. Baricitinib (BARI), an oral Janus Kinase 1/2 inhibitor, is approved in Europe, Japan, and other countries, for treatment of adults with moderate-to-severe AD who are candidates for systemic therapy. This post hoc analysis of a Phase 3 topical corticosteroid (TCS) combination therapy trial (BREEZE-AD7) aims to characterize patients who might benefit most from BARI.

METHOD

Classification and regression tree (CART) analysis was used to identify baseline predictors for patients treated with BARI 4-mg, who achieved ≥ 75% improvement in Eczema Area and Severity Index (EASI75), or EASI75 or Itch Numerical Rating Scale (NRS) ≥ 4-point improvement at week 16 (responders), versus non-responders. Subgroup efficacy analyses were performed based on identified predictor variables, combined with Itch NRS < 7/ ≥ 7. Missing data were imputed as non-responder.

RESULTS

Baseline body surface area (BSA) was identified by CART as strongest variable predicting response to BARI at week 16, with a cut-off around 40% (BSA ≤ 40%). When combining BSA with itch severity, highest response rates were achieved by BARI patients with BSA ≤ 40%/Itch NRS ≥ 7 at baseline. In this subgroup, 69% and 58% of patients treated with BARI 4-mg achieved EASI75 and Itch NRS ≥ 4-point response at week 16, respectively. While these response rates were 65% and 50% for BARI 4-mg patients with baseline BSA ≤ 40%/Itch NRS < 7, they were 33% and 11% in BSA > 40%/Itch NRS < 7, and 32% and 49% in BSA > 40%/Itch NRS ≥ 7 subgroups, respectively.

CONCLUSION

Using a machine learning approach, patients with moderate-to-severe AD and a BSA affecting 10-40% and Itch NRS ≥ 7 were characterized as likely to benefit most from BARI 4-mg TCS combination therapy. This was confirmed by subgroup analyses, which showed that these patients are most likely to show favorable response rates in improving AD signs and symptoms, specifically itch, after 16 weeks of treatment.

The lateral habenula nucleus regulates pruritic sensation and emotion

Itch is a complex aversive sensory and emotional experience. As a most upsetting symptom in many dermatological and systemic diseases, it lacks efficient treatments. The lateral habenula nucleus (LHb) encodes negative emotions in the epithalamus and has been implicated in pain and analgesia. Nevertheless, the role of the lateral habenula nucleus in the pruritic sensation and emotion remains elusive. Here we defined the crucial role of glutamatergic neurons within the lateral habenula nucleus (Glu^LHb) in itch modulation in mice. We established histamine-dependent and histamine-independent models of acute pruritus, as well as the acetone-ether-water (AEW) model of chronic pruritus. We first assessed the effects of pruritogen injection on neural activation in both medial and lateral divisions of LHb in vitro. We then demonstrated that the population activity of Glu^LHb neurons was increased during the acute itch and chronic itch-induced scratching behaviors in vivo. In addition, electrophysiological data showed that the excitability of Glu^LHb neurons was enhanced by chronic itch. Chemogenetic suppression of Glu^LHb neurons disrupted both acute and chronic itch-evoked scratching behaviors. Furthermore, itch-induced conditioned place aversion (CPA) was abolished by Glu^LHb neuronal inhibition. Finally, we dissected the LHb upstream brain regions. Together, these findings reveal the involvement of LHb in processing both the sensational and emotional components of pruritus and may shed new insights into itch therapy.

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.

Pruritus in cancer patients as a polyetiological symptom

Pruritus is one of the subjective sensations that significantly reduces the quality of life of patients. In patients with malignancies, itch can be caused by different universal or specific pathophysiological factors. This article discusses disorders that cause pruritus in cancer patients: the tumor growth on its own; pathophysiological changes associated with a number of malignancies, paraneoplastic itch, anticancer therapy, concomitant dermatoses, systemic diseases, psychosomatic disorders. Known or proposed mechanisms of the development of pruritus are presented for each of the mentioned provoking factors, and methods of treatment are described, according to the etiological factor. At the end of the article, universal methods for the correction of itching are presented, applicable in cancer patients, regardless of the pruritogenic factor. Special attention is paid to the correction of xerosis as a universal cause of itching in oncological patients.

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.

Difamilast Ointment in Japanese Adult and Pediatric Patients with Atopic Dermatitis: A Phase III, Long-Term, Open-Label Study

Introduction

Phosphodiesterase 4 (PDE4), which regulates inflammatory cytokine production leading to atopic dermatitis (AD), is selectively inhibited by difamilast. The objective of this phase III, long-term, open-label study was to evaluate the safety and efficacy of topical difamilast in Japanese adult and pediatric patients with AD.

Methods

Adult patients (n = 166) began treatment with difamilast 1% ointment, and pediatric patients began treatment with difamilast 0.3% ointment (n = 144) or difamilast 1% ointment (n = 56). Treatment was continued twice daily for 52 weeks. All patients had an Investigator’s Global Assessment (IGA) score of 2 (mild), 3 (moderate), or 4 (severe/very severe), and an AD-affected body surface area (BSA) of ≥ 5% before treatment, with no restriction on the upper limit for the AD-affected BSA.

Results

During therapy, 120 adult patients (72.3%) and 178 pediatric patients (89.0%) experienced treatment-emergent adverse events (TEAEs), most of which were mild or moderate in severity. Discontinuation due to TEAEs was reported in 13 adult patients (7.8%) and in 7 pediatric patients (3.5%). Treatment-related adverse events were reported in 14 adult patients (8.4%) and 16 pediatric patients (8.0%), most frequently dermatitis atopic (1.8%) and acne (1.2%) in adult patients and dermatitis atopic and pigmentation disorder (each 2.0%) in pediatric patients. The cumulative success rates in Eczema Area and Severity Index (EASI)-75 in adult and pediatric patients were 55.4% and 73.5%, respectively, at week 52, and the cumulative success rates increased from week 4 to week 52. The cumulative success rates in IGA score showed the same trend as those in EASI -75.

Conclusions

This study demonstrates that difamilast ointments are well tolerated and effective in Japanese adult and pediatric patients with AD when applied twice daily for 52 weeks, and are expected to be used for a long-term treatment for AD.

Clinical Trial Registration

Clinical Trials.gov identifier: NCT03961529.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00751-9.

Skin Care Product Rich in Antioxidants and Anti-Inflammatory Natural Compounds Reduces Itching and Inflammation in the Skin of Atopic Dermatitis Patients

The atopic dermatitis (AD) complex pathogenesis mechanism reveals marked changes of certain signaling factors as well as some morphological alterations in the epidermis. Reduced resilience against environmental factors and oxidative stress often makes the treatment with corticosteroids or tacrolismus ointments indispensable. In view of the correlation between oxidative stress and AD pathological factors, antioxidants can be incorporated into AD management strategies. This study investigates a curly kale, apple and green tea-containing natural extract rich in antioxidants for its effects on signaling inflammatory molecules and skin barrier enhancement in human epidermal keratinocytes- (NHEKs) based cell assays. Furthermore, the skin penetration on porcine ears was measured ex vivo using Raman micro spectroscopy. Finally, in a double-blind half-side, placebo-controlled clinical study, the effects of a formulation containing this extract were analyzed for the influence of lesion severity, epidermal barrier function, and pruritus in mild to moderately AD patients. Summarizing our results: The extract reduces expression of inflammatory cytokines in keratinocytes and increases barrier-related molecules. The verum formulation with a very high antioxidant capacity used in AD patients with mild to moderate lesions reduces itching, local SCORAD, and improves barrier function and the hydration of skin lesions.

Strategies for using topical corticosteroids in children and adults with eczema

BACKGROUND

Eczema is a common skin condition. Although topical corticosteroids have been a first-line treatment for eczema for decades, there are uncertainties over their optimal use.

OBJECTIVES

To establish the effectiveness and safety of different ways of using topical corticosteroids for treating eczema.

SEARCH METHODS

We searched databases to January 2021 (Cochrane Skin Specialised Register; CENTRAL; MEDLINE; Embase; GREAT) and five clinical trials registers. We checked bibliographies from included trials to identify further trials.

SELECTION CRITERIA

Randomised controlled trials in adults and children with eczema that compared at least two strategies of topical corticosteroid use. We excluded placebo comparisons, other than for trials that evaluated proactive versus reactive treatment.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods, with GRADE certainty of evidence for key findings. Primary outcomes were changes in clinician-reported signs and relevant local adverse events. Secondary outcomes were patient-reported symptoms and relevant systemic adverse events. For local adverse events, we prioritised abnormal skin thinning as a key area of concern for healthcare professionals and patients.

MAIN RESULTS

We included 104 trials (8443 participants). Most trials were conducted in high-income countries (81/104), most likely in outpatient or other hospital settings. We judged only one trial to be low risk of bias across all domains. Fifty-five trials had high risk of bias in at least one domain, mostly due to lack of blinding or missing outcome data. Stronger-potency versus weaker-potency topical corticosteroids Sixty-three trials compared different potencies of topical corticosteroids: 12 moderate versus mild, 22 potent versus mild, 25 potent versus moderate, and 6 very potent versus potent. Trials were usually in children with moderate or severe eczema, where specified, lasting one to five weeks. The most reported outcome was Investigator Global Assessment (IGA) of clinician-reported signs of eczema. We pooled four trials that compared moderate- versus mild-potency topical corticosteroids (420 participants). Moderate-potency topical corticosteroids probably result in more participants achieving treatment success, defined as cleared or marked improvement on IGA (52% versus 34%; odds ratio (OR) 2.07, 95% confidence interval (CI) 1.41 to 3.04; moderate-certainty evidence). We pooled nine trials that compared potent versus mild-potency topical corticosteroids (392 participants). Potent topical corticosteroids probably result in a large increase in number achieving treatment success (70% versus 39%; OR 3.71, 95% CI 2.04 to 6.72; moderate-certainty evidence). We pooled 15 trials that compared potent versus moderate-potency topical corticosteroids (1053 participants). There was insufficient evidence of a benefit of potent topical corticosteroids compared to moderate topical corticosteroids (OR 1.33, 95% CI 0.93 to 1.89; moderate-certainty evidence). We pooled three trials that compared very potent versus potent topical corticosteroids (216 participants). The evidence is uncertain with a wide confidence interval (OR 0.53, 95% CI 0.13 to 2.09; low-certainty evidence). Twice daily or more versus once daily application We pooled 15 of 25 trials in this comparison (1821 participants, all reported IGA). The trials usually assessed adults and children with moderate or severe eczema, where specified, using potent topical corticosteroids, lasting two to six weeks. Applying potent topical corticosteroids only once a day probably does not decrease the number achieving treatment success compared to twice daily application (OR 0.97, 95% CI 0.68 to 1.38; 15 trials, 1821 participants; moderate-certainty evidence). Local adverse events Within the trials that tested 'treating eczema flare-up' strategies, we identified only 26 cases of abnormal skin thinning from 2266 participants (1% across 22 trials). Most cases were from the use of higher-potency topical corticosteroids (16 with very potent, 6 with potent, 2 with moderate and 2 with mild). We assessed this evidence as low certainty, except for very potent versus potent topical corticosteroids, which was very low-certainty evidence.  Longer versus shorter-term duration of application for induction of remission No trials were identified. Twice weekly application (weekend, or 'proactive therapy') to prevent relapse (flare-ups) versus no topical corticosteroids/reactive application Nine trials assessed this comparison, generally lasting 16 to 20 weeks. We pooled seven trials that compared weekend (proactive) topical corticosteroids therapy versus no topical corticosteroids (1179 participants, children and adults with a range of eczema severities, though mainly moderate or severe). Weekend (proactive) therapy probably results in a large decrease in likelihood of a relapse from 58% to 25% (risk ratio (RR) 0.43, 95% CI 0.32 to 0.57; 7 trials, 1149 participants; moderate-certainty evidence). Local adverse events We did not identify any cases of abnormal skin thinning in seven trials that assessed skin thinning (1050 participants) at the end of treatment. We assessed this evidence as low certainty. Other comparisons  Other comparisons included newer versus older preparations of topical corticosteroids (15 trials), cream versus ointment (7 trials), topical corticosteroids with wet wrap versus no wet wrap (6 trials), number of days per week applied (4 trials), different concentrations of the same topical corticosteroids (2 trials), time of day applied (2 trials), topical corticosteroids alternating with topical calcineurin inhibitors versus topical corticosteroids alone (1 trial), application to wet versus dry skin (1 trial) and application before versus after emollient (1 trial). No trials compared branded versus generic topical corticosteroids and time between application of emollient and topical corticosteroids.

AUTHORS' CONCLUSIONS

Potent and moderate topical corticosteroids are probably more effective than mild topical corticosteroids, primarily in moderate or severe eczema; however, there is uncertain evidence to support any advantage of very potent over potent topical corticosteroids. Effectiveness is similar between once daily and twice daily (or more) frequent use of potent topical corticosteroids to treat eczema flare-ups, and topical corticosteroids weekend (proactive) therapy is probably better than no topical corticosteroids/reactive use to prevent eczema relapse (flare-ups). Adverse events were not well reported and came largely from low- or very low-certainty, short-term trials. In trials that reported abnormal skin thinning, frequency was low overall and increased with increasing potency. We found no trials on the optimum duration of treatment of a flare, branded versus generic topical corticosteroids, and time to leave between application of topical corticosteroids and emollient. There is a need for longer-term trials, in people with mild eczema.

Onset of Symptom Relief Reported in Daily Diaries in Patients With Atopic Dermatitis Treated With Baricitinib in a United States Clinical Trial (BREEZE-AD5)

BACKGROUND

Itch and sleep disturbance due to itch are burdensome symptoms associated with atopic dermatitis (AD). Rapid onset of action is important for AD treatments to improve quality of life and relieve suffering.

OBJECTIVES

This subanalysis evaluated how quickly baricitinib 1-mg and 2-mg reduced itch and associated sleep disturbance during the first 7 days after treatment initiation in a phase 3, double-blind, placebo-controlled trial.

METHODS

Adult patients with AD were randomized 1:1:1 to placebo (N = 147), baricitinib 1 mg (N = 147) or baricitinib 2 mg (N = 146). Patients kept daily diaries, completing the Itch Numeric Rating Scale (NRS) (itch severity from 0 = no itch to 10 = worst itch imaginable) and the Atopic Dermatitis Sleep Scale (ADSS) to measure sleep disturbance (number of nighttime awakenings because of itch). Mixed model repeated measures analysis was used to analyze change from day 1 to day 7 values.

RESULTS

Patients receiving either dose of baricitinib had a 9.9% decrease in itch NRS scores from baseline to Day 2 vs 1.5% decrease for placebo (significant between-group least squares mean [LSM] difference: 8.3; 95% CI -12.66 to -3.89; P = .0002). Baricitinib 2 mg reduced nighttime awakenings due to itch (ADSS item 2) at day 2 by 25.2% vs 3.9% in the placebo group (between-group LSM difference: -21.4, P = .0025). Baricitinib 2 mg continued to demonstrate a statistically significant difference from placebo in sleep symptoms at day 7 (LSM difference -23.9; P = .001).

CONCLUSIONS

Baricitinib 2-mg provided relief from itching and sleep disturbance in patients with AD, beginning the day after taking first dose.Clinical trials at www.clinicaltrials.gov: BREEZE-AD5 (NCT03435081).

Can crowdsourced data help to optimize atopic dermatitis treatment? Comparing web search data and environmental data in Germany

BACKGROUND

Atopic dermatitis (AD) is one of the most common chronic skin diseases worldwide, showing various manifestations and having a severe impact on quality of life. As previous studies demonstrated, internet search analysis can help identify public interest in diseases and possible influencing factors on search behavior.

OBJECTIVE

To identify AD-related topics of interest in Germany using internet search volume.

METHODS

Google Ads Keyword Planner was used to identify AD-related search terms including their search volume in Germany on a national level as well as in 16 selected cities from January 2016 to December 2019. Identified keywords were qualitatively analyzed, and temporal trends as well as the influence of seasonal and environmental factors on search volume were assessed.

RESULTS

Overall, 1222 AD-related search terms with a search volume of 8 842 360 searches were identified. An increase from 2016 to 2019 and seasonal peaks from January to April of each year were observed. Nationwide, the search volume correlated with mean monthly temperature and sun duration. With increasing temperature and sun duration, a significant decrease in search queries was observed. The most populated cities showed the lowest number of searches per 100 000 inhabitants (Berlin, Hamburg, and Munich). In the eight categories formed (comorbidities, general, influential factors, localization, stage of life, symptoms/severity, therapy/information, and questions on AD), the highest proportion of search queries were assigned to the category "therapy/information" in most cities. In this category, a focus on the topics of "alternative medicine" and "home remedies" could be observed.

CONCLUSION

The overall high and increasing search volume indicates a high interest in AD-related topics, especially regarding treatment and disease education. Information provided by internet search volume analyses can optimize AD therapy and patient-centered care by providing insight into patient needs and predicting potential climatic trigger factors.

When topical therapy of atopic dermatitis fails: a guide for the clinician

INTRODUCTION

While topical medications are the first line of treatment for mild-to-moderate atopic dermatitis, they are ineffective in individuals with diffuse disease and moderate-to-severe atopic itch. For these individuals, as well as those who do not respond to topical treatments, systemic medicines are typically essential and helpful.

AREAS COVERED

We conducted a review of the literature to identify established systemic therapies, novel biologic agents, and recent advances in the pathophysiology of atopic dermatitis. The review discusses these data, which show that the majority of atopic itch medications now in development target the type 2 immune axis and brain sensitization, two main etiologies of atopic itch. We emphasize the evidence, efficacy, and side effect profiles of currently available systemic medications for atopic itch, as well as future potential for tailored therapy.

EXPERT OPINION

We give our professional opinion on the current state of knowledge about atopic eczema pathogenesis and the innovative targets and therapies for atopic itch that include MRGPRX2, periostin, gabaergic medicines, and JAK/STAT inhibitors. Additionally, we discuss patient populations that stand to benefit the most from targeting these molecules or utilizing these drugs, as well as those who may face a disproportionate weight of adverse effects.

Itch: Pathogenesis and treatment

Itch pathogenesis is broadly characterized into histaminergic and nonhistaminergic pathways and transmitted via 2 main receptor families: G protein-coupled receptors and transient receptor potential channels. In the skin, itch is primarily transmitted by unmyelinated type C and thinly myelinated type Aδ nerve fibers. Crosstalk between the immune and neural systems modulates itch transmission at the skin, spinal cord, and brain. Among the many known pruritogens, Th2 cytokines, such as interleukin-4, interleukin-13, interleukin-31, and thymic stromal lymphopoietin, are particularly important mediators that signal through shared Janus kinase pathways, representing novel targets for novel itch therapeutics. Emerging evidence has also revealed that the opioidergic system is a potent modulator of itch transmission, with increased μ-opioid activity and decreased κ-opioid activity contributing to itch pathogenesis. Optimal management of itch requires that treatment approaches be tailored to specific etiologic itch subtypes. When the etiology is unknown and patients are given a diagnosis of chronic pruritus of unknown origin, treatment should be guided by the presence of Th2 polarization, often reflected by increased blood eosinophils. In the second article of this 2-part series, we outline our current understanding of itch pathogenesis and discuss available and emerging treatments for itch.

TRPV1 mediates itch-associated scratching and skin barrier dysfunction in DNFB-induced atopic dermatitis mice

In chronic pruritic diseases such as atopic dermatitis (AD), pruritus and skin lesions are exacerbated by scratching in clinical and experimental settings. TRPV1 is known to mediate itch and neurogenic inflammation, but the role of TRPV1 in itch-associated scratching in AD is poorly understood. In this study, we examined the efficacy of cutting off nails and TRPV1 antagonist, ruthenium red (RR) in a murine model of AD induced by DNFB and further investigated the underlying mechanism. Nail clipping or RR could markedly ameliorate the general AD-like symptoms as manifested by the reduced clinical severity of dermatitis, IgE and Th2-related cytokine levels, and mast cell degranulation. Moreover, scratching behaviour, the levels of pruritogenic mediators, including HIS, TSLP, IL-31 and SP, and skin pH and TEWL were all significantly decreased in nail clipping or RR-treated mice, suggesting a reduction in itch-associated scratching and skin barrier defects. Immunofluorescence staining and Western blot results revealed that antipruritic effect of nail clipping or RR in AD may be explained, at least in part, by the suppression of TRPV1 activation. In summary, these data show that TRPV1 mediates itch-associated scratching and subsequent skin barrier defects, suggesting its potential as a therapeutic target in AD.

The Influence of Microbiome Dysbiosis and Bacterial Biofilms on Epidermal Barrier Function in Atopic Dermatitis-An Update

Atopic dermatitis (AD) is a common inflammatory dermatosis affecting up to 30% of children and 10% of adults worldwide. AD is primarily driven by an epidermal barrier defect which triggers immune dysregulation within the skin. According to recent research such phenomena are closely related to the microbial dysbiosis of the skin. There is growing evidence that cutaneous microbiota and bacterial biofilms negatively affect skin barrier function, contributing to the onset and exacerbation of AD. This review summarizes the latest data on the mechanisms leading to microbiome dysbiosis and biofilm formation in AD, and the influence of these phenomena on skin barrier function.

Current Clinical Options for the Management of Itch in Atopic Dermatitis

Pruritus is the most burdensome and prevalent symptom in patients suffering from atopic dermatitis. Treating atopic itch has historically been a challenge due to multiple underlying mechanisms within its pathogenesis and an incomplete understanding of them. In recent years, our understanding of these mechanisms have increased tremendously and subsequently, new treatments have reached the market that target the pathophysiology of atopic itch from different angles. In addition, there are several promising new treatments currently in development and trials. In the current article, we discuss these currently available treatment options, their available evidence and efficacy, and highlight some of the more recent advancements in the field.

Pearls for Managing Atopic Dermatitis in Patients With Low Socioeconomic Status

Atopic dermatitis (AD) is a chronic inflammatory dermatosis presenting with inflamed and itchy skin. Recent studies have shown an inverse relationship between socioeconomic status and the severity of AD. Low socioeconomic status (LSES) individuals with AD face specific barriers that may impede management. These include forgoing doctor's appointments due to transportation costs, inability to take time off from work, and lack of affordable childcare services. Unaffordable medications and over-the-counter products for managing AD further present as significant challenges for LSES patients. This article aims to offer practical and affordable recommendations to help mitigate the challenges faced by LSES patients with AD and thereby alleviate disease burden and improve treatment outcomes.

Difamilast ointment, a selective phosphodiesterase 4 inhibitor, in paediatric patients with atopic dermatitis: A phase 3 randomised double-blind, vehicle-controlled trial

Background

In atopic dermatitis (AD), phosphodiesterase 4 (PDE4) inhibition reduces proinflammatory mediators and cytokines. Difamilast is a new selective PDE4 inhibitor.

Objectives

To demonstrate the superiority of topical difamilast to vehicle in Japanese paediatric patients with AD.

Methods

This was a phase III randomized, double‐blind, vehicle‐controlled trial. Patients aged 2–14 years with an Investigator Global Assessment (IGA) score of 2 or 3 received difamilast 0·3% (n = 83), difamilast 1% (n = 85) or vehicle (n = 83) ointment twice daily for 4 weeks.

Results

The primary endpoint was the percentage of patients with an IGA score of 0 or 1 with improvement by at least two grades at week 4. The success rates in IGA score at week 4 were 44·6%, 47·1% and 18·1% in the difamilast 0·3%, difamilast 1% and vehicle groups, respectively. Both difamilast groups demonstrated significantly higher success rates in IGA score compared with vehicle at week 4 [difamilast 0·3% (P < 0·001); difamilast 1% (P < 0·001)]. Regarding secondary endpoints, improvements in Eczema Area and Severity Index (EASI; improvement of ≥ 50%, ≥ 75% and ≥ 90% in overall score) at week 4 were significantly higher in patients in the difamilast 0·3% and 1% groups than those in the vehicle group. EASI score in the difamilast 0·3% and 1% groups was significantly reduced compared with that of patients in the vehicle group at week 1. The significant difference between both the difamilast groups and the vehicle groups was maintained from week 1 through to week 4. Most treatment‐emergent adverse events were mild or moderate, and no serious events or deaths were reported.

Conclusions

Difamilast 0·3% and 1% ointments are superior to vehicle and well tolerated in Japanese paediatric patients with AD.

Approach to the Patient with Chronic Pruritus

Chronic pruritus (itch lasting ≥6 weeks) is a bothersome chief complaint that may present in a broad variety of diseases. Most itch-causing diagnoses fit into 1 of 5 categories (inflammatory, secondary to systemic disease, neuropathic, chronic pruritus of undetermined origin, and psychogenic itch) and this broad differential can be narrowed using key findings in the history and physical. In this article, we discuss which key findings are most pertinent for narrowing this differential and guiding further workup and treatment, as well as how to treat many itchy conditions.

Therapeutic patient education: the Avène-Les-Bains experience

Originally developed to improve the management of serious chronic diseases such as diabetes mellitus, obesity, cardiovascular diseases, asthma and as aftercare following oncological treatments, therapeutic patient education (TPE) has been extended to other situations, including chronic dermatoses such as atopic dermatitis, eczema and psoriasis. In this article, we provide a brief overview of the development, implementation and evaluation of TPE at the Avène-Les-Bains Hydrotherapy Center, France.

Itch and Sleep Improvements with Baricitinib in Patients with Atopic Dermatitis: A Post Hoc Analysis of 3 Phase 3 Studies

Introduction

Burdensome symptoms of atopic dermatitis include itch and sleep disturbance. This post hoc analysis reports the effect of baricitinib on itch and sleep disturbance during the first week of treatment in 3 phase 3 studies.

Methods

Patients were randomized 2:1:1:1 to once-daily placebo or baricitinib 1 mg, 2 mg, or 4 mg in the BREEZE-AD1 and -AD2 studies and 1:1:1 to once-daily placebo or baricitinib 2 mg or 4 mg in the BREEZE-AD7 study. Topical corticosteroids were only allowed in BREEZE-AD7. Patients completed the itch numerical rating scale and atopic dermatitis sleep scale (ADSS) items 1–3 using an electronic daily diary. Data were analyzed by study as least squares mean percent change from baseline in daily scores for the randomized patients. Mixed model repeated measures analysis was used to analyze change from baseline values.

Results

A total of 624, 615, and 329 patients were randomized in BREEZE-AD1, -AD2, and -AD7, respectively. Itch severity significantly improved with baricitinib 2 mg and 4 mg versus placebo starting at day 2 (1 day after first dose) in BREEZE-AD1 and -AD7 and at day 1 in BREEZE-AD2. Patients’ ability to fall asleep (ADSS item 1) significantly improved with baricitinib 2 mg and 4 mg versus placebo starting at day 2 in all three studies. There were significant improvements in patients waking due to itch (ADSS item 2) with baricitinib 4 mg versus placebo starting at day 2 in all three studies. Patients’ ability to return to sleep after being woken by itch (ADSS item 3) was significantly improved with baricitinib 4 mg versus placebo starting at day 2 in BREEZE-AD1 and -AD2 and at day 4 in BREEZE-AD7.

Conclusion

Rapid onset of action, typically 1 day after taking the first dose of baricitinib, was observed consistently for the burdensome symptoms of itch and sleep disturbance.

ClinicalTrials.gov identifiers

BREEZE-AD1, NCT03334396; BREEZE-AD2, NCT03334422; BREEZE-AD7, NCT03733301.

Dupilumab treatment induced similar improvements in signs, symptoms, and quality of life in adults with moderate-to-severe atopic dermatitis with baseline Eczema Area and Severity Index score < 24 or ≥ 24

BACKGROUND

In multiple phase 3 trials, dupilumab improved signs, symptoms (including pruritus), and quality-of-life (QoL) in adults with moderate-to-severe atopic dermatitis (AD). In Italy, dupilumab received innovation status but is currently only reimbursed by the National Health Service for adults with Eczema Area Severity Index (EASI) scores ≥24. This analysis assesses disease burden and dupilumab efficacy in adults with EASI scores above and below this threshold.

METHODS

This post-hoc analysis included 299 adults pooled from two, randomized, placebocontrolled, phase 3 trials, LIBERTY AD CAFÉ (NCT02755649) and LIBERTY AD CHRONOS (NCT02260986), who received the approved dupilumab regimen (300mg every 2 weeks) or placebo, with concomitant topical corticosteroids. EASI, Peak Pruritus Numerical Rating Scale (PP-NRS), and Dermatology Life Quality Index (DLQI) were assessed in patients with EASI scores ≥20 to <24 and ≥24 at week 16.

RESULTS

At baseline, EASI was weakly correlated with PP-NRS and DLQI (Spearman's correlation coefficient = 0.22 and 0.29, respectively). At week 16, in both the EASI<24 and EASI≥24 populations, respectively, significantly more patients vs control achieved: ≥50% improvement in EASI (95.5% vs 55.6%; 80.6% vs 33.1%); ≥3-point improvement in PP-NRS (68.4% vs 35.3%; 55.3% vs 17.7%); and ≥4-point improvement in DLQI (83.3% vs 43.8%; 84.2% vs 41.9%); from baseline. Dupilumab was generally well tolerated with an acceptable safety profile.

CONCLUSIONS

Dupilumab treatment improves signs, symptoms, and QoL in moderate-to-severe AD adults with EASI<24, who can present with high disease burden. Opportunity may exist to use additional parameters to define disease severity and access to new therapies.

Central opioid receptors mediate morphine-induced itch and chronic itch via disinhibition

Opioids such as morphine are mainstay treatments for clinical pain conditions. Itch is a common side effect of opioids, particularly as a result of epidural or intrathecal administration. Recent progress has advanced our understanding of itch circuits in the spinal cord. However, the mechanisms underlying opioid-induced itch are not fully understood, although an interaction between µ-opioid receptor (MOR) and gastrin-releasing peptide receptor (GRPR) in spinal GRPR-expressing neurons has been implicated. In this study we investigated the cellular mechanisms of intrathecal opioid-induced itch by conditional deletion of MOR-encoding Oprm1 in distinct populations of interneurons and sensory neurons. We found that intrathecal injection of the MOR agonists morphine or DAMGO elicited dose-dependent scratching as well as licking and biting, but this pruritus was totally abolished in mice with a specific Oprm1 deletion in Vgat+ neurons [Oprm1-Vgat (Slc32a1)]. Loss of MOR in somatostatin+ interneurons and TRPV1+ sensory neurons did not affect morphine-induced itch but impaired morphine-induced antinociception. In situ hybridization revealed Oprm1 expression in 30% of inhibitory and 20% of excitatory interneurons in the spinal dorsal horn. Whole-cell recordings from spinal cord slices showed that DAMGO induced outward currents in 9 of 19 Vgat+ interneurons examined. Morphine also inhibited action potentials in Vgat+ interneurons. Furthermore, morphine suppressed evoked inhibitory postsynaptic currents in postsynaptic Vgat- excitatory neurons, suggesting a mechanism of disinhibition by MOR agonists. Notably, morphine-elicited itch was suppressed by intrathecal administration of NPY and abolished by spinal ablation of GRPR+ neurons with intrathecal injection of bombesin-saporin, whereas intrathecal GRP-induced itch response remained intact in mice lacking Oprm1-Vgat. Intrathecal bombesin-saporin treatment reduced the number of GRPR+ neurons by 97% in the lumber spinal cord and 91% in the cervical spinal cord, without changing the number of Oprm1+ neurons. Additionally, chronic itch from DNFB-induced allergic contact dermatitis was decreased by Oprm1-Vgat deletion. Finally, naloxone, but not peripherally restricted naloxone methiodide, inhibited chronic itch in the DNFB model and the CTCL model, indicating a contribution of central MOR signalling to chronic itch. Our findings demonstrate that intrathecal morphine elicits itch via acting on MOR on spinal inhibitory interneurons, leading to disinhibition of the spinal itch circuit. Our data also provide mechanistic insights into the current treatment of chronic itch with opioid receptor antagonist such as naloxone.

Pruritus in psoriasis and atopic dermatitis: current treatments and new perspectives

Psoriasis and atopic dermatitis (AD) are two common chronic inflammatory skin diseases. Although showing different etiology and clinical manifestations, patients with either disease suffer from low health-related quality of life due to pruritus (dermal itch). Recent studies have revealed that more than 85% of psoriasis patients suffer from pruritus, and it is also the dominating symptom of AD. However, as this is a non-life treating symptom, it was partly neglected for years. In this review, we focus on current findings as well as the impact and potential treatments of pruritus in these two skin diseases. We first distinguish the type of itch based on involved mediators and modulators. This clear delineation between the types of pruritus based on involved receptors and pathways allows for precise treatment. In addition, insights into recent clinical trials aimed to alleviate pruritus by targeting these receptors are presented. We also report about novel advances in combinatorial treatments, dedicated to the type of pruritus linked to a causal disease. Altogether, we suggest that only a focused treatment tailored to the primary disease and the underlying molecular signals will provide fast and sustained relief of pruritus associated with psoriasis or AD.

Inhibition of mite-induced dermatitis, pruritus, and nerve sprouting in mice by the endothelin receptor antagonist bosentan

BACKGROUND

Endothelin-1 (EDN1) can evoke histamine-independent pruritus in mammals and is upregulated in the lesional epidermis of atopic dermatitis (AD). EDN1 increases the production of interleukin 25 (IL-25) from keratinocytes to accelerate T helper type 2 immune deviation. Plasma EDN1 levels are positively correlated with the clinical severity and itch intensity of AD. Therefore, we hypothesized that the inhibition of EDN1 might be useful for treating atopic inflammation and itch and investigated the effects of the topical application of the EDN1 receptor antagonist bosentan on the skin inflammation and itch in a murine AD model.

METHODS

We analyzed the mite-induced AD-like NC/Nga murine model, which was topically applied with bosentan or ethanol control every day for 3 weeks. We also subjected in vitro primary sensory neuron culture systems to nerve elongation and branching assays after EDN1 stimulation.

RESULTS

Topical application of bosentan significantly attenuated the development of mite-induced AD-like skin inflammation, dermatitis scores, ear thickness, scratching bouts, and serum level of thymus and activation-regulated chemokine in NC/Nga mice. Bosentan application also significantly reduced the gene expression of Il13, Il17, and Ifng in the treated lesions. Histologically, the number of infiltrated dermal cells, the epidermal EDN1 expression, and the number of intraepidermal nerve fibers were significantly inhibited upon bosentan application. While EDN1 significantly elongated the neurites of dorsal root ganglion cells in a dose- and time-dependent manner, bosentan treatment attenuated this.

CONCLUSIONS

EDN1 plays a significant role in mite-induced inflammation and itch. Topical bosentan is a potential protective candidate for AD.

Scratching damages tight junctions through the Akt-claudin 1 axis in atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a common, chronic, severely pruritic, eczematous skin disease that seriously deteriorates the quality of life of patients. Scratching is a cardinal symptom of AD. Although the vicious itch-scratch cycle continues and aggravates skin barrier dysfunction in AD, how scratching induces skin barrier dysfunction through tight junctions remains unclear.

AIM

To study the effect of scratching on tight junctions in the itch-scratch cycle.

METHODS

Scratching behaviour and skin barrier dysfunction on the neck and back in an AD mouse model were assessed. The expression of tight junction proteins was compared between the neck and back mice, and the mechanisms underlying the involvement of Akt/CLDN1 pathways in this process were explored.

RESULTS

We used oxazolone to induce AD on the neck or back of mice. There was significantly more scratching behaviour and more pronounced skin barrier dysfunction with the neck than with the back. Downregulation of claudin-1 (CLDN1) and upregulation of Akt phosphorylation in skin were well correlated with scratching behaviour in this AD model. Furthermore, SC79, an agonist of Akt phosphorylation, could downregulate CLDN1 expression in HaCaT cells. An antagonist of Akt phosphorylation (LY294002) was used to treat the AD mice; this treatment rescued CLDN1 expression through inhibiting Akt phosphorylation in skin, and importantly, also inhibited the scratching behaviour induced by AD.

CONCLUSION

The results reveal the underlying mechanism of tight junction damage promoted by scratching in the itch-scratch cycle of AD, and opens a new avenue to pruritus management in AD, through Akt antagonists.

HP-NAP ameliorates OXA-induced atopic dermatitis symptoms in mice

BACKGROUND

Atopic dermatitis (AD) is a chronic skin inflammatory disease characterized by disequilibrium between Th1/Th2 lymphocytes. Helicobacter pylori neutrophil-activating protein (HP-NAP) has been reported that it has the potential immunomodulatory effect able to regulate the Th1/Th2 balance.

OBJECTIVE

This study aimed to investigate the therapeutic effect of HP-NAP in AD mice model.

METHODS

The model of AD was built with oxazolone (OXA) in BALB/c mice, then HP-NAP was used to treat AD by intraperitoneal injection. Ear thickness was measured by a digital thickness gauge. The ears tissues were collected and subjected to hematoxylin-eosin (H&E) and toluidine blue (TB) staining. The mRNA expression levels of inflammatory cytokines (IL-1β, IL-5, IL-6, and TNF-α) in ear tissue were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The secretion of IgE, IL-4, and IFN-γ was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Treatment with HP-NAP successfully alleviated the symptoms of AD, such as erythema, horny substance, and swelling. The infiltration of lymphocytes and mast cells were significantly reduced following HP-NAP therapy. The secretion of IgE and IL-4 was significantly attenuated following treatment with HP-NAP. Additionally, HP-NAP observably downregulated inflammatory cytokine expression (e.g. IL-1β, IL-5, IL-6, and TNF-α) in ear tissues.

CONCLUSIONS AND CLINICAL RELEVANCE

Taken together, our results showed that HP-NAP possessed the potential to be a novel immunomodulatory candidate drug against AD.

Effects of Formulation Excipients on Skin Barrier Function in Creams Used in Pediatric Care

Semisolid dosage forms are recommended for the dermal care of babies and children. If we look at the ingredients of these preparations, there are still many cases in which there are substances (occlusive agents, preservatives) that no longer meet certain requirements of the modern age, so it is timely to replace them with other substances. The aim of this work was to formulate a science-based formulation with new components that keep or improve its moisturizing properties, rheological parameters, and microbiological stability. Occlusive oils, like white petrolatum and liquid paraffin and the preservative parabens are traditional ingredients in oil in water creams, were replaced with white beeswax, sunflower oil, and phenoxyethanol, respectively. Cocoa butter, urea, and glycerol were added to improve long-lasting hydration and support the barrier function of the reformulated creams. The rheological properties of the formulations were determined. The effects of the preparations on skin hydration and on the barrier function of the skin were tested. Furthermore, microbiological stability was investigated. The result of the reformulation was an o/w cream that provided a good longer-lasting hydration effect; supported the barrier function of the baby skin without occlusion; and had adequate consistency, easy spreading, a pleasant skin feeling, proper pH, and good microbiological stability.

Antipruritic Effect of Ethyl Acetate Extract from Fructus cnidii in Mice with 2,4-Dinitrofluorobenzene-Induced Atopic Dermatitis

Atopic dermatitis (AD) is a common inflammatory skin disease characterized by intense pruritus and skin lesions. The exact cause of AD is not yet known and the available therapeutic strategies for AD are limited. Fructus cnidii is commonly used in traditional Chinese medicine as an herb for treating chronic itch. However, the mechanism underlying the antipruritic effects of Fructus cnidii is not well understood. In the present study, we investigated the antipruritic effect of locally administered ethyl acetate extract from Fructus cnidii (EAEFC) to 2,4-dinitrofluorobenzene- (DNFB-) induced AD in a mouse model. The scratching behavior, skin thickness, dermatitis score, weight, blood immunoglobulin E (IgE) level, and itch-related cytokine levels were subsequently monitored and evaluated. Results showed that EAEFC treatment attenuated the DNFB-induced AD-like symptoms by alleviating the skin lesions and decreasing the dermatitis score. Hematoxylin and eosin (H&E) and toluidine blue (TB) staining analyses demonstrated that EAEFC mitigated the DNFB-induced increase in skin thickness and prevented the infiltration of mast cells. Behavioral tests showed that EAEFC decreased the DNFB-induced acute and chronic scratching behaviors. Furthermore, EAEFC reduced the levels of itch-related cytokines, such as thymic stromal lymphopoietin (TSLP), interleukin- (IL-) 17, IL-33, and IL-31, and the DNFB-induced boost in serum IgE. Collectively, these results suggest that EAEFC is a potential therapeutic candidate for the treatment of chronic itch in AD.

Safety considerations when using drugs to treat pruritus

Introduction: Treatment for chronic pruritus ranges from use of topical formulations to newer biologic agents. Targeting treatment to the underlying etiology is key in reducing the burden of disease while avoiding systemic or adverse effects.Areas covered: This review details the effective medical treatments used in various etiologies of chronic itch with a focus on the potential adverse effects and safety data available for each.Expert opinion: New drug developments in the areas of neural signaling and immune targeting show great promise for the future of chronic itch treatment. These new therapies broaden the available treatment options but also pose new considerations for safety and adverse effects.

Phase 2, randomized, double-blind, placebo-controlled, 4-week study to evaluate the safety and efficacy of OPA- 15406 (difamilast), a new topical selective phosphodiesterase type-4 inhibitor, in Japanese pediatric patients aged 2-14 years with atopic dermatitis

The safety and efficacy of OPA-15406 (international non-proprietary name, difamilast; also referred to as MM36), a new topical, selective phosphodiesterase type-4 inhibitor, in Japanese pediatric patients with atopic dermatitis aged 2-14 years were evaluated in a phase 2, randomized, double-blind, vehicle-controlled, 4-week study. Seventy-three patients were randomized 1:1:1 to receive OPA-15406 0.3%, OPA-15406 1% or vehicle ointment twice daily for 4 weeks. The mean age of patients was similar across treatment groups. No deaths or serious treatment-emergent adverse events were reported; all treatment-emergent adverse events were mild or moderate in severity. The incidence of treatment-emergent adverse events leading to treatment discontinuation was 4.2% (1/24) in the OPA-15406 0.3% group, 4.0% (1/25) in the OPA-15406 1% group and 16.7% (4/24) in the vehicle group, all of which were worsening of atopic dermatitis. Both OPA-15406 groups demonstrated a higher incidence of success in the Investigator Global Assessment score compared with the vehicle group over the 4-week study. The OPA-15406 groups also showed greater improvements from baseline compared with the vehicle group in the Investigator Global Assessment score, Eczema Area and Severity Index overall score and subscale (erythema, induration/papulation, excoriation and lichenification) scores, Visual Analog Scale pruritus score, Patient-Oriented Eczema Measure score, and percentage of affected body surface area over the 4-week study. Topical OPA-15406 twice daily for 4 weeks was considered a safe and effective treatment option in this phase 2 study in pediatric patients with atopic dermatitis, and phase 3 development is currently ongoing.

Is Itch Intensity in Atopic Dermatitis Associated with Skin Colonization by Staphylococcus aureus?

Background:

Atopic dermatitis (AD) is a highly pruritic skin condition of unclear pathogenesis. Patients with AD are predisposed to colonization by Staphylococcus aureus due to deficiencies in the mechanical and immunological functions of the skin barrier. Recent studies indirectly show that S. aureus may aggravate disease flares in AD.

Aims:

The aim was to assess the relationship between S. aureus skin colonization and itch intensity in patients with AD.

Materials and Methods:

The SCORAD index components reflecting itch intensity (excoriations, subjective evaluation of pruritus, and sleep loss) were assessed in 33 adult patients with AD. Swabs were taken from lesional and nonlesional skin. The prevalence and abundance of S. aureus were assessed. Statistical analysis was performed to correlate the microbiological results with the clinical parameters. The control group consisted of 36 healthy volunteers.

Results:

Lesional and nonlesional skin showed a high frequency of S. aureus colonization when compared with controls (81.8% and 57.6% vs 5.6%, respectively, P < 0.0001). The mean concentration (points) of S. aureus was 2.01 ± 1.25, 1.06 ± 1.14, and 0.11 ± 0.46, respectively (P < 0.0001). S. aureus abundance on lesional/nonlesional skin positively correlated with excoriations and sleep loss (rho = 0.69, P < 0.00001; rho = 0.44, P < 0.01; rho = 0.41, P < 0.02; and rho = 0.34, P < 0.05, respectively). The mean values of excoriations were higher in patients colonized by S. aureus than in patients without S. aureus carriage.

Conclusion:

S. aureus skin colonization may be one of the factors aggravating itch in AD. It may be hypothesized that restoring the natural composition of the skin microbiome may reduce pruritus intensity.

Scratching Counteracts IL-13 Signaling by Upregulating the Decoy Receptor IL-13Rα2 in Keratinocytes

The vicious itch–scratch cycle is a cardinal feature of atopic dermatitis (AD), in which IL-13 signaling plays a dominant role. Keratinocytes express two receptors: The heterodimeric IL-4Rα/IL-13Rα1 and IL-13Rα2. The former one transduces a functional IL-13 signal, whereas the latter IL-13Rα2 works as a nonfunctional decoy receptor. To examine whether scratch injury affects the expression of IL-4Rα, IL-13Rα1, and IL-13Rα2, we scratched confluent keratinocyte sheets and examined the expression of three IL-13 receptors using quantitative real-time PCR (qRT-PCR) and immunofluorescence techniques. Scratch injuries significantly upregulated the expression of IL13RA2 in a scratch line number-dependent manner. Scratch-induced IL13RA2 upregulation was synergistically enhanced in the simultaneous presence of IL-13. In contrast, scratch injuries did not alter the expression of IL4R and IL13RA1, even in the presence of IL-13. Scratch-induced IL13RA2 expression was dependent on ERK1/2 and p38 MAPK signals. The expression of IL-13Rα2 protein was indeed augmented in the scratch edge area and was also overexpressed in lichenified lesional AD skin. IL-13 inhibited the expression of involucrin, an important epidermal terminal differentiation molecule. IL-13-mediated downregulation of involucrin was attenuated in IL-13Rα2-overexpressed keratinocytes, confirming the decoy function of IL-13Rα2. Our findings indicate that scratching upregulates the expression of the IL-13 decoy receptor IL-13Rα2 and counteracts IL-13 signaling.