Cutaneous dysbiosis may amplify barrier dysfunction in patients with atopic dermatitis

A sticky mess-Are moisturizers overused in dermatitis care?

Microbial dysbiosis is increasingly understood to influence allergic sensitization and skin barrier defects in dermatitis. Occlusion, such as from moisturizers, fosters microbial dysbiosis, and increases itch in many patients with dermatitis. Nevertheless, use of moisturizers in dermatitis remains part of dermatologic guidelines. This is a review of the evidence of benefits and adverse effects of moisturizers in dermatitis and a proposal for moderation in their clinical use.

Exploring the skin microbiome in atopic dermatitis pathogenesis and disease modification

Inflammatory skin diseases such as atopic eczema (atopic dermatitis [AD]) affect children and adults globally. In AD, the skin barrier is impaired on multiple levels. Underlying factors include genetic, chemical, immunologic, and microbial components. Increased skin pH in AD is part of the altered microbial microenvironment that promotes overgrowth of the skin microbiome with Staphylococcus aureus. The secretion of virulence factors, such as toxins and proteases, by S aureus further aggravates the skin barrier deficiency and additionally disrupts the balance of an already skewed immune response. Skin commensal bacteria, however, can inhibit the growth and pathogenicity of S aureus through quorum sensing. Therefore, restoring a healthy skin microbiome could contribute to remission induction in AD. This review discusses direct and indirect approaches to targeting the skin microbiome through modulation of the skin pH; UV treatment; and use of prebiotics, probiotics, and postbiotics. Furthermore, exploratory techniques such as skin microbiome transplantation, ozone therapy, and phage therapy are discussed. Finally, we summarize the latest findings on disease and microbiome modification through targeted immunomodulatory systemic treatments and biologics. We believe that targeting the skin microbiome should be considered a crucial component of successful AD treatment in the future.

Comprehensive analysis of phenotypes and transcriptome characteristics reveal the best atopic dermatitis mouse model induced by MC903

BACKGROUND

Although several mouse models of exogenous-agent-induced atopic dermatitis (AD) are currently available, the lack of certainty regarding their similarity with human AD has limited their scientific value. Thus, comprehensive evaluation of the characteristics of mouse models and their similarity with human AD is essential.

OBJECTIVE

To compare six different exogenous-agent-induced AD mouse models and find out the optimum models for study.

METHODS

Female BALB/c mice underwent induction of AD-like dermatitis by MC903 alone or in combination with ovalbumin (OVA), dinitrofluorobenzene (DNFB) alone or in combination with OVA, OVA alone, or Staphylococcus aureus. Gross phenotype, total immunoglobulin E (IgE) level, histopathological manifestations, and skin lesion transcriptome were analyzed, and metagenomic sequencing of the gut microbiome was performed.

RESULTS

The DNFB plus OVA model showed the highest disease severity, while the OVA model showed the lowest severity. The MC903 and MC903 plus OVA models showed high expression of T-helper (Th)2- and Th17-related genes; the DNFB and DNFB plus OVA models showed upregulation of Th1-, Th2-, and Th17-related genes; while the S. aureus inoculation model showed more enhanced Th1 and Th17 immune responses. In contrast to the other models, the OVA-induced model showed the lowest expression levels of inflammation-related genes, while the MC903 model shared the largest overlap with human AD profiles. The intestinal microbiota of all groups showed significant differences after modeling.

CONCLUSION

Each AD mouse model exhibited different characteristics. The MC903 model was the best to recapitulate most features of human AD among these exogenous-agent-induced AD models.

The use of essential oils in atopic dermatitis: a review

Atopic dermatitis (AD) has become a common childhood disease that affects a large number of children worldwide and has become a chronic skin disease that causes huge economical and psychological damage to the whole family. Despite the use of steroids, immunosuppressants, and various topical preparation, the prognosis is still poor. Hence, this review aimed to explore the potential of using essential oils (EO) as an active ingredient in managing AD. The review was completed by using Pubmed, Scopus, and Medline to search for relevant articles that study the pathophysiology of AD, the properties of EO, the use of EO in managing AD, and the suitable advanced formulation to incorporate EO. From the review conducted, it was concluded that EO have huge potential in managing AD and can be used as complimentary therapeutic agents in AD treatment. Scientists and industries should venture into commercializing more topical products with EO to help manage AD more effectively.

Polymorphic markers of several immune regulatory genes modulate the susceptibility for eczema and related phenotypes in children

Background

Eczema is associated with multiple genes regulating epidermal barrier functions and immunological pathways. However, their epistatic interactions are not well studied. This cross-sectional study investigated the relationship between childhood eczema phenotypes and single-nucleotide polymorphisms (SNPs) of immune regulatory genes.

Methods

One thousand three hundred and twenty-nine Chinese eczematous children and 1,179 non-allergic controls were recruited. Nine SNPs of immune regulatory genes signal transducer and activator of transcription 3 (STAT3), interleukin-10 (IL10), transforming growth factor-beta 1 (TGFB1), and IL-6 receptor (IL6R) were genotyped by TaqMan genotyping assays. Logistic regression was used to analyze the associations between SNPs and eczema phenotypes. Generalized multifactor dimensionality reduction (GMDR) was used to examine epistatic interactions among these SNPs as well as those reported by our group [filaggrin (FLG) and 11q13] for eczema phenotypes.

Results

TGFB1_rs1800469 was found to be associated with eczema [odds ratio (OR), 0.82; 95% confidence interval (CI): 0.73-0.92; P=0.001], atopic eczema (OR, 0.83; 95% CI: 0.72-0.95; P=0.009) and allergic rhinitis (OR, 0.84; 95% CI: 0.74-0.95; P=0.005). We also found a trend between IL10_rs1800872 and increased total immunoglobulin E (IgE) levels (P=0.009). Epistatic interaction among IL10_rs3021094, TGFB1_rs1800469, IL6R_rs2228145, and STAT3_rs4796793 were found for total IgE [testing accuracy (TA), 0.551; cross-validation consistency (CVC), 10; P=0.014]. Mean log-transformed total IgE (logIgE) levels in high-risk cases, low-risk cases, high-risk controls, and low-risk controls were 2.75, 2.60, 1.90, and 1.81 respectively (P=0.019 for trend).

Conclusions

Functional TGFB1 polymorphism is associated with both eczema and allergic rhinitis, suggesting the role of TGF-β1 in allergy susceptibility. IL10 may be associated with increased total IgE levels. Interaction among immune regulatory genes modulates total IgE levels.

The mycobiome in atopic diseases: Inducers and triggers

Atopic diseases are characterized by type 2 inflammation, with high levels of allergen-specific TH2 cell immune responses and elevated production of IgE. These common disorders have increased in incidence around the world, which is partly explained by detrimental disturbances to the early-life intestinal microbiome. Although most studies have focused exclusively on bacterial members of the microbiome, intestinal fungi have started to be recognized for their impact on host immune development and atopy pathogenesis. From this perspective, we review recent findings demonstrating the strong interactions between members of the mycobiome and the host immune system early in life, leading to immune tolerance during eubiosis or inducing sensitization and overt TH2 cell responses during dysbiosis. Current evidence places intestinal fungi as central players in the development of allergic diseases and potential targets for atopy prevention and treatments.

Probiotics and Prebiotics Orally Assumed as Disease Modifiers for Stable Mild Atopic Dermatitis: An Italian Real-Life, Multicenter, Retrospective, Observational Study

The role of the skin-gut axis in atopic dermatitis (AD) remains a subject of debate, limiting non-pharmacological interventions such as probiotics and prebiotics. To improve understanding of their potential as a monotherapy for stable mild cases, we conducted a real-life, multicenter, retrospective observational study in Italy. We administered three selected bacteria (Bifidobacterium animalis subsp. lactis BS01, Lactiplantibacillus plantarum LP14, and Lacticaseibacillus rhamnosus LR05) orally to patients with mild atopic dermatitis without a placebo control group, following up for 12 weeks. Clinical assessments using the Scoring Atopic Dermatitis (SCORAD), Eczema Area and Severity Index (EASI), and Three-Item Severity (TIS) score were conducted on 144 enrolled patients (average age: 25.1 ± 17.6 years). Notably, both pruritus and AD-related lesions (erythema, edema/papules, excoriation) exhibited significant clinical and statistical improvement (p < 0.001) after 12 weeks of exclusive probiotic and prebiotic use. These preliminary results suggest a potential link between the skin-gut microbiome and support the rationale for using specific probiotics and prebiotics in mild AD, even for maintenance, to reduce flares and dysbiosis.

Analysis of Adverse Reactions of Cosmetics in Chinese Han Population in Recent Five Years

Background

There are still some gaps in the summary and generalization of cosmetic-related adverse reaction reports.

Objective

The aim of this study is to summarize and analyze the occurrence of cosmetic adverse reactions in Shanghai Han population by using available survey data.

Materials and Methods

Collection, statistics and analysis of patients with cosmetic adverse reactions in Shanghai Huashan Hospital from 2017 to 2021.

Results

Among the 1004 patients, most of them (96.71%) were diagnosed as cosmetic contact dermatitis, which often occurred within 3 days of using cosmetics (51.79%). A total of 260 patients were tested with patch test, but the compliance rate was only 18.08%. Among them, 240 patients underwent additional European standard allergen tests, and positive allergens were detected in 210 cases (87.5%). Univariate analysis revealed that dosage form (emulsion and cream), age (≤25 years) and the allergic ingredients triethanolamine, rose oil, propylene glycol, thiomersal and musk ambrette are associated with the occurrence of cosmetic adverse reactions within seven days. A logit prediction model was also successfully constructed: Logit (P) = 1.710-0.796×1 + 1.185×2 -3.650X3-1.335X4.

Conclusion

This study complements the data reported on cosmetic adverse reactions in the Chinese Han population and suggests that in future clinical diagnosis and data collection, emphasis should be placed on patch testing, combining the patch test with cosmetic protoplast with the European standard allergen test to improve the detection rate.

Fungal dysbiosis and decreased tear mucin at the conjunctiva in patients with conjunctival mucosa-associated lymphoid tissue lymphoma

OBJECTIVE

This study aimed to examine the differences in the fungal microbiome between patients with conjunctival mucosa-associated lymphoid tissue (MALT) and healthy controls using metagenomic analysis.

METHODS AND ANALYSIS

This case-control study was conducted at Osaka University Hospital in Osaka, Japan, from April 2015 to March 2022. Twenty-five consecutive patients with conjunctival MALT lymphoma and 25 healthy volunteers were included. Metagenomic analysis using Internal Transcribed Spacer (ITS)1 deep sequencing and hierarchical clustering was performed to investigate differences in the fungal microbiome. To assess tear environmental change, we measured tear mucin concentrations using ELISA.

RESULTS

Detailed analyses showed fungal dysbiosis and changes in β-diversity within the conjunctiva of patients with conjunctival MALT lymphoma. Hierarchical clustering revealed that the participants could be divided into three clusters according to the Malassezia abundance: cluster I (Malassezia abundance above 70%), cluster II (Malassezia abundance 25%-70%) and cluster II (Malassezia abundance below 25%). Most patients were included in cluster I, whereas most of healthy controls were included in cluster III. The differences were significant. Tear mucin concentrations were significantly lower in patients with MALT compared with healthy controls.

CONCLUSION

The metagenomic analysis using ITS1 deep sequencing was useful for identifying the differences in commensal fungi between patients with MALT lymphoma and healthy individuals. The increased prevalence of the Malassezia genus and the decreased levels of tear mucin can lead to an allergic response of the conjunctiva, resulting in the pathogenesis associated with conjunctival MALT lymphoma. Therefore, it may be beneficial to initiate treatment when a high abundance Malassezia is detected.

Atopic Dermatitis and Ulcerative Colitis Successfully Treated with Upadacitinib

Background and Objectives: JAK inhibitors entered current clinical practice as treatment for several immune-related diseases and, recently, for atopic dermatitis. These drugs target the Janus Kinase intracellular cascade, rendering them suitable for treating both Th1 and Th2 immune-mediated responses. Materials and Methods: We report the case of a 36-year-old male patient presenting an overlap of ulcerative colitis, a Th1-related disease, and atopic dermatitis, a Th2-mediated condition. Treatment with upadacitinib was initiated, and laboratory and instrumental follow-ups were carried out for 8 months. Results: The complete and persistent clinical remission of both conditions was observed at a low dose of 15 mg of upadacitinib, even though ulcerative colitis guidelines usually recommend a dosage of 45 mg. No serious adverse responses to therapy were reported. Conclusions: Upadacitinib may be the most suitable management strategy in subjects with coexisting severe conditions mediated by Th1 inflammation, such as ulcerative colitis, and by Th2 cytokines, such as atopic dermatitis.

The Effectiveness of Allergen Immunotherapy in Adult Patients with Atopic Dermatitis Allergic to House Dust Mites

Background and objectives: Allergen immunotherapy (AIT) is not a first-line therapy in atopic dermatitis (AD) and its effectiveness has been criticised. Objectives: The efficacy and safety of AIT in adult patients with AD and monosensitisation to house dust mites (HDMs) were investigated. Materials and Methods: A total of 37 patients were included in this double-blind, placebo-controlled study. Patients were eligible if they were diagnosed with AD; had moderate-to-severe AD according to the Eczema Area and Severity Index (EASI) with at least 7.1 points, the % BSA (body surface area) scale with at least 16 points, and the IsGA (investigator global assessment) scale with 3 points; had positive skin prick tests (SPTs); and were positive for the specific immunoglobulin E (sIgE) response to D. pteronyssinus and D. farinae extracts, as well as Der p 1 and Der f1. The patients received Purethal mites (20,000 AUeq/mL, HAL Allergy, Leiden, The Netherlands) with the extract allergens D. pteronyssinus and D. farinae (50/50%) or a placebo for 12 months. The primary outcomes included changes in EASI, % BSA, and IsGA due to SCIT between the start and after 12 months of therapy. Results: In the study group, significant improvement was observed in terms of the EASI score from 43 ± 8.2 to 21 ± 5.9 points, % BSA from 72 ± 18 to 28 ± 11 points, and IsGA from 4.5 ± 0.5 to 1.5 ± 0.5 points in comparison with the placebo after 1 year of AIT. Additionally, the proportion of patients who achieved success in the IsGA (IsGA < 2) was significantly better in comparison to the placebo with 13/20 (65%) vs. 4/14 (29%), respectively (p < 0.05). Conclusions: HDM-AIT effectively improved atopic dermatitis in patients that strictly qualified for desensitisation with a confirmed monovalent mite allergy.