Skin Microbiome in Atopic Dermatitis Edslev, Sofie M; Agner, Tove; Andersen, Paal S
Acta dermato-venereologica,
06/2020, Letnik:
100, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Atopic dermatitis is a common inflammatory skin disease with a complex pathogenesis that includes imbalanced immune system signalling, impaired skin barrier and enhanced Staphylococcus aureus skin ...colonization. The skin bacterial communities are characterized by increasing abundance of S. aureus, leading to reduced diversity compared with the bacterial communities on healthy skin, and increasing disease severity. In contrast, fungal communities are richer and more diverse on the skin of patients with atopic dermatitis, although distribution of the most common species is similar in patients and controls. Filaggrin deficiency in atopic dermatitis skin might be related to the enhanced skin colonization by S. aureus. In addition, S. aureus expressing variant virulence factors have been shown to elicit atopic dermatitis-like phenotypes in mice, indicating that specific S. aureus strains can induce flare-ups. This review aims to provide an overview of the recent literature on the skin microbiome in atopic dermatitis.
Summary
The present guideline summarizes all aspects of patch testing for the diagnosis of contact allergy in patients suspected of suffering, or having been suffering, from allergic contact ...dermatitis or other delayed‐type hypersensitivity skin and mucosal conditions. Sections with brief descriptions and discussions of different pertinent topics are followed by a highlighted short practical recommendation. Topics comprise, after an introduction with important definitions, materials, technique, modifications of epicutaneous testing, individual factors influencing the patch test outcome or necessitating special considerations, children, patients with occupational contact dermatitis and drug eruptions as special groups, patch testing of materials brought in by the patient, adverse effects of patch testing, and the final evaluation and patient counselling based on this judgement. Finally, short reference is made to aspects of (continuing) medical education and to electronic collection of data for epidemiological surveillance.
Tape-stripping is a minimally invasive approach for skin sampling that captures the cutaneous immune/barrier abnormalities in atopic dermatitis (AD). However, tape-strips have not been used to ...evaluate molecular changes with therapeutic targeting. In this study, we sought to characterize the proteomic signature of tape-strips from AD patients, before and after dupilumab therapy. Twenty-six AD patients were treated with every-other-week dupilumab 300 mg for 16 weeks. Tape-strips from lesional and non-lesional skin were collected before and after treatment, and analyzed with the Olink proteomic assay. Using criteria of fold-change>1.5 and FDR < 0.05, 136 proteins significantly decreased after dupilumab treatment, corresponding to an overall mean improvement of 66.2% in the lesional vs. non-lesional AD proteome. Significant decreases after dupilumab were observed in immune markers related to general inflammation (MMP12), Th2 (CCL13/CCL17), Th17/Th22 (IL-12B, CXCL1, S100A12), and innate immunity (IL-6, IL-8, IL-17C), while the Th1 chemokines CXCL9/CXCL10 remained elevated. Proteins related to atherosclerosis/cardiovascular risk (e.g., SELE/E-selectin, IGFBP7, CHIT1/ chitotriosidase-1, AXL) also significantly decreased after treatment. Dupilumab therapy suppressed AD-related immune biomarkers and atherosclerosis/cardiovascular risk proteins. Tape-strip proteomics may be useful for monitoring therapeutic response in real-life settings, clinical trials, and longitudinal studies for AD and beyond.
The aim of this study was to investigate the amount of protein in stratum corneum in atopic dermatitis (AD) patients and healthy controls, using tape stripping technique. Furthermore, to compare two ...different methods for protein assessment. Tape stripping was performed in AD patients and healthy controls to collect stratum corneum samples and subsequently analysed with two different methods: Squame Scan, which gives an estimate of total protein (soluble and insoluble) and Micro BCA protein determination kit which measures soluble protein. Significant differences in cumulative protein content between AD lesional, AD non-lesional and healthy control skin was found using the Squame Scan as well as the Micro BCA protein determination kit. AD patients had significantly lower amount of protein, both total protein and soluble protein compared to healthy controls. Furthermore, soluble protein formed 82% of total protein in AD lesional skin, compared to 17-24% for AD non-lesional skin and healthy control. A decreasing amount of total protein with increasing stratum corneum depth was found for all skin types. Significant differences in stratum corneum protein content between AD lesional, AD non-lesional and healthy control skin were revealed, independent of method used.
Summary
Background
Allergic contact dermatitis (ACD) caused by nail acrylates, also including methacrylates and cyanoacrylates here, is being increasingly reported.
Methods
A retrospective study in ...11 European Environmental Contact Dermatitis Research Group (EECDRG) clinics collected information on cases of ACD caused by nail acrylates diagnosed by aimed testing between 2013 and 2015.
Results
Among 18 228 studied patients, 136 had ACD caused by nail acrylates (0.75%; 95%CI: 0.60–0.90), representing 67.3% (95%CI: 60.4–73.7) of ACD cases caused by acrylates. There were 135 females and 1 male, with a mean age ± standard deviation of 36.7 ± 12.2 years; 59 (43.4%) were exposed as consumers, and 77 (56.6%) were occupationally exposed. Occupational cases were more frequent in southern Europe (83.7%), and were younger (mean age of 33.4 ± 8.9 years); most developed ACD during the first year at work (65.0%), and at least 11.7% had to leave their jobs. Skin lesions involved the hands in 121 patients (88.9%) and the face in 50 (36.8%), with the face being the only affected site in 14 (10.3%). Most patients reacted to two or more acrylates on patch testing, mainly to 2‐hydroxyethyl methacrylate (HEMA) (92.5%), 2‐hydroxypropyl methacrylate (88.6%), ethylene glycol dimethacrylate (69.2%), and ethyl cyanoacrylate (9.9%).
Conclusions
Nail cosmetics were responsible for the majority of ACD cases caused by acrylates, affecting nail beauticians and consumers, and therefore calling for stricter regulation and preventive measures. As HEMA detects most cases, and isolated facial lesions may be overlooked, inclusion of this allergen in the baseline series may be warranted.
Objective Albeit a pivotal risk for the development of hand eczema (HE), the exposure-response relationship between wet work and HE remains to be further investigated. Knowledge on exposure-response ...is important regarding preventive measures, medico-legal regulations and job-counseling. Recently, a job-exposure matrix (JEM) for wet work was developed, providing information on the likelihood of wet work. By combining the JEM with data on HE we aimed to investigate the relationship between extent of wet work and HE. Methods This study is a case-referent study including patients registered in the National Database of Contact Allergy, Denmark, and comprises data on sex, age, atopic dermatitis, HE, face eczema and patch testing results. Patients with HE served as cases and patients with facial eczema served as referents. Information on profession was retrieved from the DOC*X database in accordance with the DISCO-88 classification system. A wet-work-specific JEM provides - for each profession - an estimate for (i) the likelihood of wet work lasting ≥2 hours/day and (ii) the average number of hours of wet work per day. Results After two hours of wet hands and glove wear, the odds ratio (OR) was 3.49 and 3.19, respectively, for females and 2.41 and 1.82, respectively, for males. Females had a higher risk of HE than males with probability of wet hands <75% (OR 2.34, 95% CI 2.12-2.58 compared to males 1.68, 95% CI 1.22-2.31) and regarding glove wear at all exposure levels. Conclusion Our data confirms a close association between wet work and HE. Exposure lasting less than the current definition of wet work (having wet hands for ≥2 hours per day) may be of importance.
Atopic dermatitis (AD) is a common inflammatory skin disease characterized by an epidermal barrier impairment, as well as a Th2/Th22-skewed immune response, both favoring skin colonization with
...Staphylococcus aureus
. Colonization is strongly related to severity of the disease, and a reduction of
S. aureus
has been found to alleviate symptoms. Lactic acid bacteria (LAB) produce antimicrobial compounds such as organic acids and bacteriocins and are widely used as probiotics. The aim of this study was to isolate LAB and screen for antibacterial effect specifically toward
S. aureus
clonal complex type 1. A total of 680 LAB were isolated from fermented vegetables and swab samples from healthy volunteers (vaginal, stool and skin). Screening for antibacterial activity toward
S. aureus
, narrowed the field of isolates down to four LAB strains with high antibacterial activity. The activity varied according to the specific LAB strain and the origin of the strain. The results suggested different modes of action, including co-aggregation, expression of bacteriocins and production of specific organic acids. However, the ability to acidify the surroundings appeared as the main effect behind inhibition of
S. aureus.
Broth microdilution assays showed a significant reduction of
S. aureus
growth when using down to 10% cell free supernatant (CFS). Our results underline the use of specific living LAB or their CFS as potential future treatment strategies to reduce
S. aureus
colonization of AD skin.
Summary
Background
Hairdressers are at risk of developing occupational contact dermatitis because of their intense contact with wet work in combination with chemicals.
Objectives
To perform an ...analysis of a cohort study of hairdressers with occupational contact dermatitis recognized in the period 2006–2011, focusing on individual and environmental factors associated with the disease.
Methods
The study was a descriptive, register‐based survey including all hairdressers with recognized occupational contact dermatitis in Denmark in the period January 2006 to September 2011. Data were obtained from the Danish National Board of Industrial Injuries.
Results
The study comprised 381 patients (373 women and 8 men). The median age was 25 years, 64.8% were apprentices, and 35.2% were fully trained hairdressers. The prevalence of atopic dermatitis was 36.0%, and was significantly higher among apprentices than among fully trained hairdressers (44.9% and 19.4%, respectively) (p < 0.001). Of the patients, 48.3% had their dermatitis recognized as occupational irritant contact dermatitis, 46.7% had their dermatitis recognized as as occupational allergic contact dermatitis or combined allergic and irritant contact dermatitis, and 5.0% were recognized as having occupational contact urticaria.
Conclusion
The low median age, the high percentages of atopic dermatitis in apprentices and the fact that more apprentices than fully trained hairdressers had recognized occupational contact dermatitis underlines the importance of early prevention.
Atopic dermatitis (AD) patients have an altered skin bacterial community, with an abundance of Staphylococcus aureus associated with flares, highlighting that microbial organisms may be important for ...disease exacerbation. Despite strong evidence of association between bacterial skin colonisation and AD, very limited knowledge regarding the eukaryotic microbial community, including fungi and ectoparasites, in AD exists. In this study, we compared the skin and nasal eukaryotic microbial community between adult AD patients (n = 55) and non-AD healthy controls (n = 45) using targeted 18S rRNA amplicon sequencing. Analysis was based on the presence or absence of eukaryotic microorganisms.
The cutaneous composition of the eukaryotic microbial community and the alpha-diversity differed significantly between AD patients and non-AD individuals, with increased species richness on AD skin. Alpha-diversity and beta-diversity were similar on lesional and non-lesional skin of patients. The ectoparasite Demodex folliculorum and the yeast Geotrichum candidum were significantly more prevalent on the skin of AD patients. The prevalence of D. folliculorum on lesional skin was greater among patients recently treated with topical corticosteroid. Malassezia was one of the most frequently detected genera at all sites, with M. globosa and M. restricta being the most prevalent. M. restricta was under represented in the anterior nares of AD patients as compared to the non-AD control population.
Significant differences in the eukaryotic microbial communities were found between AD patients and non-AD individuals, with the most striking finding being the significantly overrepresentation of D. folliculorum on AD skin. Whether D. folliculorum can contribute to skin inflammation in AD needs further investigation.
Abstract
There has been considerable research into the understanding of the healthy skin microbiome. Similarly, there is also a considerable body of research into whether specific microbes contribute ...to skin disorders, with atopic dermatitis (AD) routinely linked to increased
Staphylococcus aureus (S. aureus)
colonisation. In this study, the epidermal surface of participants was sampled using swabs, while serial tape-stripping (35 tapes) was performed to sample through the stratum corneum. Samples were taken from AD patients and healthy controls, and the bacterial communities were profiled by metabarcoding the universal V3-V4 16S rRNA region. Results show that the majority of bacterial richness is located within the outermost layers of the stratum corneum, however there were many taxa that were found almost exclusively at the very outermost layer of the epidermis. We therefore hypothesise that tape-stripping can be performed to investigate the ‘core microbiome’ of participants by removing environmental contaminants. Interestingly, significant community variation between AD patients and healthy controls was only observable at the epidermal surface, yet a number of individual taxa were found to consistently differ with AD status across the entire epidermis (i.e. both the epidermal surface and within the epidermis). Sampling strategy could therefore be tailored dependent on the hypothesis, with sampling for forensic applications best performed using surface swabs and outer tapes, while profiling sub-surface communities may better reflect host genome and immunological status.
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