Atopic Dermatitis: Disease Features, Therapeutic Options, and a Multidisciplinary Approach

The Role of the Microbiota in the Pathogenesis and Treatment of Atopic Dermatitis-A Literature Review

Atopic dermatitis (AD) is a chronic inflammatory skin condition with a high prevalence worldwide. AD pathogenesis is complex and consists of immune system dysregulation and impaired skin barrier, influenced by genetic and environmental factors. The purpose of the review is to show the complex interplay between atopic dermatitis and the microbiota. Human microbiota plays an important role in AD pathogenesis and the course of the disease. Dysbiosis is an important factor contributing to the development of atopic diseases, including atopic dermatitis. The gut microbiota can influence the composition of the skin microbiota, strengthening the skin barrier and regulating the immune response via the involvement of bacterial metabolites, particularly short-chain fatty acids, in signaling pathways of the gut-skin axis. AD can be modulated by antibiotic intake, dietary adjustments, hygiene, and living conditions. One of the promising strategies for modulating the course of AD is probiotics. This review offers a summary of how the microbiota influences the development and treatment of AD, highlighting aspects that warrant additional investigation.

Effects of abrocitinib on pruritus and eczema symptoms and tolerance in patients with moderate‑to‑severe atopic dermatitis in randomized, double‑blind and placebo‑controlled trials: A systematic review and a meta‑analysis

Abrocitinib is a highly selective Janus kinase 1 (JAK1) inhibitor that can block a multitude of inflammatory signaling pathways that underlie atopic dermatitis (AD). In addition, abrocitinib inhibits JAK1 signaling in sensory neurons to alleviate acute and chronic pruritus during AD. However, substantial variations in efficacy and safety risks remain due to variations in doses applied in clinical use. Therefore for the present study, differences in the efficacy and tolerability of 100 and 200 mg abrocitinib for treating pruritus and eczema symptoms in patients with moderate-to-severe AD were evaluated compared with placebo. Specifically, randomized controlled trials (RCTs) of abrocitinib compared with placebo for the treatment of moderate-to-severe AD were searched on Pubmed, E.B. Stephens Company, China National Knowledge Infrastructure, Wanfang Medical network, Web of Science and related Clinical Trials Registry up to November 2023. In total, two researchers evaluated the quality of the included literature according to the Cochrane Handbook of Systematic Reviews. RevMan 5.3 software was used to conduct a meta-analysis of the efficacy and safety indicators in a cross-comparison of the effects exerted by placebo and 100 and 200 mg abrocitinib. A total of 1,825 patients with moderate-to-severe AD were included across five double-blind, placebo RCTs. Compared with the placebo group, during the double-blind trial period, significant improvements were observed in the investigator's global assessment score, response rate of eczema area and severity index (EASI)-50, EASI-75, EASI-90 and pruritus numerical rating scale (P-NRS) in the 100 and 200 mg abrocitinib groups (P<0.05). However, pairwise control analysis of the 100 and 200 mg group yielded significant differences (P<0.05) in all of the aforementioned therapeutic indicators except for the P-NRS score. In terms of safety, compared with the placebo group, there were significantly higher incidence of nausea, upper respiratory tract viral infection, infections and infestations in the 100 mg abrocitinib group (P<0.05). In addition, there were significantly higher incidence of nausea, gastrointestinal disorder, headache and dizziness in the 200 mg group (P<0.05). There were also significant differences in the incidence of nausea, gastrointestinal disorder and dizziness between the 100 and 200 mg groups (P<0.05). For patients with moderate-to-severe AD, oral administration of 100 or 200 mg abrocitinib once/day was concluded to ameliorate skin pruritus and eczema symptoms to varying degrees, with the efficacy significantly superior at the 200 mg dose. However, the risk of a number of adverse reactions, such as headache, dizziness, nausea and gastrointestinal dysfunction, is also significantly increased. Therefore, patients should be made aware of the risk of adverse drug effects prior to the administration of long-term high abrocitinib doses. Furthermore, large-scale, multi-center, rigorous clinical trials remain necessary to validate the findings from the present study.

Unraveling Atopic Dermatitis: Insights into Pathophysiology, Therapeutic Advances, and Future Perspectives

Atopic dermatitis (AD) is an inflammatory skin condition that frequently develops before the onset of allergic rhinitis or asthma. More than 10% of children are affected by this serious skin condition, which is painful for the sufferers. Recent research has connected the environment, genetics, the skin barrier, drugs, psychological factors, and the immune system to the onset and severity of AD. The causes and consequences of AD and its cellular and molecular origins are reviewed in this paper. The exploration of interleukins and their influence on the immunological pathway in AD has been facilitated by using relevant biomarkers in clinical trials. This approach enables the identification of novel therapeutic modalities, fostering the potential for targeted translational research within the realm of personalized medicine. This review focuses on AD's pathophysiology and the ever-changing therapeutic landscape. Beyond the plethora of biologic medications in various stages of approval or development, a range of non-biologic targeted therapies, specifically small molecules, have emerged. These include Janus kinase (JAK) inhibitors like Baricitinib, Upadacitinib, and Abrocitinib, thus expanding the spectrum of therapeutic options. This review also addresses the latest clinical efficacy data and elucidates the scientific rationale behind each targeted treatment for atopic dermatitis.

Nonsteroidal Approaches for Atopic Dermatitis: A Clinical Update

Topical corticosteroids (TCSs) are the most widely used treatment for atopic dermatitis (AD), but they can have adverse effects such as skin atrophy, telangiectasias, and hypopigmentation, especially with prolonged use of higher potency steroids. Many patients also have a fear of using TCSs, known as "corticophobia." With the development of biologics and Janus kinase inhibitors, a nonsteroidal approach to the treatment of AD may be possible and may be preferred by certain patients. Given what is known about these nonsteroidal therapies, we propose a structured treatment ladder and action plan that can guide clinicians and patients on the use of these therapies for the treatment of AD. The ladder divides nonsteroidal medication classes into treatments for exacerbation versus maintenance therapies in an escalating order of increasing potential for adverse effects, both real and perceived. This treatment algorithm proposal paves the way for a potential nonsteroidal approach to managing AD.

Skin delivery of synthetic benzoyl pterostilbenes suppresses atopic dermatitis-like inflammation through the inhibition of keratinocyte and macrophage activation

Atopic dermatitis (AD) is one of the most common skin autoimmune diseases needing continuous anti-inflammatory management. Pterostilbene is reported to exhibit anti-inflammatory activity with higher bioavailability and stability than its parent compound, resveratrol. In this study, a series of synthetic pterostilbene analogs were designed by the hybridization of pterostilbene with chalcones or benzoyl chloride. Seventeen analogs derived from pterostilbene were synthesized with differences in the positions of hydroxyl, methoxyl, or fluoro moieties. These compounds were screened by the inhibitory effect on the overexpressed Th2-associated cytokines/chemokines in the activated human keratinocytes (HaCaT). The anti-IL-5 and anti-CCL5 activity of these compounds led to the identification of three effective compounds: 3a ((E)- 4-(3,5-dimethoxystyryl)phenyl benzoate), 3d ((E)- 4-(3,5-dimethoxystyryl)phenyl 2-methoxybenzoate), and 3g ((E)- 4-(3,5-dimethoxystyryl)phenyl 2-fluorobenzoate). These benzoyl pterostilbenes also significantly decreased Th1/Th17-associated proinflammatory mediators in the activated macrophages (differentiated THP-1). The result showed that the conditioned medium of benzoyl pterostilbene-treated macrophages reduced the phosphorylated STAT3 in the keratinocytes, indicating the blockade of crosstalk between resident and immune cells. Compounds 3d and 3g generally showed greater skin absorption than 3a. The flux of 3g across barrier-defective skins mimicking the AD skin was 3-fold higher than that of across intact skin. The dinitrochlorobenzene (DNCB)-induced AD mouse model manifested that topical delivery with 3g improved the pathological signs through inhibiting cytokines/chemokines (IL-5, TNF-α, CCL17, and CCL22) and macrophage recruitment. The epidermal thickness was reduced from 76 to 55 µm after topical 3g delivery. The therapeutic activity of 3g was comparable to that of tacrolimus (TAC) used as a positive control. The benzoyl pterostilbenes attenuated the inflammation via the MAPK and c-Jun signaling. Furthermore, this study provided experimental evidence of benzoyl pterostilbene analogs for therapeutic potential on AD.

Key Factors in the Complex and Coordinated Network of Skin Keratinization: Their Significance and Involvement in Common Skin Conditions

The epidermis serves many vital roles, including protecting the body from external influences and healing eventual injuries. It is maintained by an incredibly complex and perfectly coordinated keratinization process. In this process, desquamation is essential for the differentiation of epidermal basal progenitor cells into enucleated corneocytes, which subsequently desquamate through programmed death. Numerous factors control keratinocyte differentiation: epidermal growth factor, transforming growth factor-α, keratinocyte growth factor, interleukins IL-1-β and IL-6, elevated vitamin A levels, and changes in Ca2+ concentration. The backbone of the keratinocyte transformation process from mitotically active basal cells into fully differentiated, enucleated corneocytes is the expression of specific proteins and the creation of a Ca2+ and pH gradient at precise locations within the epidermis. Skin keratinization disorders (histologically characterized predominantly by dyskeratosis, parakeratosis, and hyperkeratosis) may be categorized into three groups: defects in the α-helical rod pattern, defects outside the α-helical rod domain, and disorders of keratin-associated proteins. Understanding the process of keratinization is essential for the pathogenesis of many dermatological diseases because improper desquamation and epidermopoiesis/keratinization (due to genetic mutations of factors or due to immune pathological processes) can lead to various conditions (ichthyoses, palmoplantar keratodermas, psoriasis, pityriasis rubra pilaris, epidermolytic hyperkeratosis, and others).

Atopic March or Atopic Multimorbidity-Overview of Current Research

The atopic march encompasses a sequence of allergic conditions, including atopic dermatitis, food allergy, allergic rhinitis, and asthma, that frequently develop in a sequential pattern within the same individual. It was introduced as a conceptual framework aimed at elucidating the developmental trajectory of allergic conditions during childhood. Following the introduction of this concept, it was initially believed that the atopic march represented the sole and definitive trajectory of the development of allergic diseases. However, this perspective evolved with the emergence of new longitudinal studies, which revealed that the evolution of allergic diseases is far more intricate. It involves numerous immunological pathological mechanisms and may not align entirely with the traditional concept of the atopic march. The objective of our review is to portray the atopic march alongside other patterns in the development of childhood allergic diseases, with a specific emphasis on the potential for a personalized approach to the prevention, diagnosis, and treatment of atopic conditions.

Atopic Dermatitis and the Risk of Infection in End-Stage Renal Disease

Background and Objectives: Atopic dermatitis (AD), also known as eczema, is a common chronic inflammatory skin condition affecting 16.5 million adults in the United States. AD is characterized by an impaired epidermal barrier that can predispose individuals to infection. End-stage renal disease (ESRD) is also commonly complicated by infections due to chronic vascular access and immune-system dysfunction, possibly related to uremia. Multiple studies have reported that renal disease is a common comorbidity in adults with atopic dermatitis. The aim of this study was to determine whether AD is a risk factor for certain infections in patients with ESRD. Materials and Methods: Using the United States Renal Data System, a retrospective cohort analysis was conducted on adult ESRD patients initiating dialysis between 2004 and 2019 to investigate associations between infections and AD in this population. Results: Of 1,526,266 patients, 2290 were identified with AD (0.2%). Infectious outcomes of interest were bacteremia, septicemia, cellulitis, herpes zoster, and conjunctivitis. In all infectious outcomes except for conjunctivitis, patients with the infectious outcomes were more likely to carry a diagnosis of AD. After controlling for demographic and clinical covariates, AD was associated with an increased risk of cellulitis (adjusted relative risk (aRR) = 1.39, 95% confidence interval (CI) = 1.31-1.47) and herpes zoster (aRR = 1.67, CI = 1.44-1.94), but not with bacteremia (aRR = 0.96, CI = 0.89-1.05), septicemia (aRR = 1.02, CI = 0.98-1.08), or conjunctivitis (aRR = 0.97, CI = 0.740-1.34). Conclusions: Overall, after controlling for demographic and clinical covariates and adjusting for person-years-at-risk, AD was associated with an increased risk for some, but not all, infections within the population of patients with ESRD.