Hand eczema and temporal variation of Staphylococcus aureus clonal complexes: A prospective observational study.

BACKGROUND: Hand eczema (HE) is frequently associated with Staphylococcus aureus; however, its role in the pathogenesis of HE is poorly understood. OBJECTIVE: To investigate the temporal variation in S aureus subtypes, ie, clonal complex (CC) types, on the hands and relate it to S aureus colonization in the nose and severity in a cohort of HE patients. METHODS: S aureus from the hands and nose of 50 adult HE patients and 50 controls was prospectively identified at 5 visits over 3 weeks. RESULTS: S aureus was identified on the hands of 23 (46%) patients at 2 or more visits and on the hands of 1 control once. Of the HE patients with S aureus colonization, 78% had the same S aureus CC type over time. Twenty-one patients had the same S aureus CC type on the hands and in the nose. Persistent colonization was strongly related to an increased disease severity. LIMITATIONS: A relatively small S aureus culture-positive population. CONCLUSION: The temporal stability of S aureus CC type and high occurrence of the identical subtypes on the hands and in the nose imply that S aureus colonization in patients with HE is of a more permanent nature. Taken together with the finding that persistent colonization and HE severity are clearly related, our results indicate that S aureus may contribute to the perpetuating course of HE.

Colonization with Staphylococcus aureus in patients with hand eczema: Prevalence and association with severity, atopic dermatitis, subtype and nasal colonization.

BACKGROUND: While Staphylococcus aureus (S. aureus) colonization has been thoroughly studied in atopic dermatitis (AD), where S. aureus is related to flares and considered a trigger factor, S. aureus colonization in hand eczema (HE) has only been sparsely studied. OBJECTIVES: To examine the 1-week prevalence of S. aureus colonization in HE patients, and its association with severity, HE subtype, AD, and nasal S. aureus colonization compared with healthy controls. METHODS: In a case-control study of 50 adult HE patients and 50 healthy controls, bacterial swabs from lesional skin (patients only), non-lesional skin (dorsal hand), and the nasal cavity were sampled for culturing of S. aureus on days 1, 3, 5 and 8. Participants were characterized by demographics, AD, HE subtype, filaggrin gene mutation status, and HE severity. RESULTS: Twenty-seven HE patients (54%) were colonized with S. aureus on the hand compared to one control (2%) (P < .01). Nasal S. aureus colonization was found in 72% of patients and 22% of controls (P < .01). For patients, S. aureus colonization on the hands was associated with an atopic HE subtype and HE severity (P = .01 and P < .01, respectively). CONCLUSIONS: Both hand and nasal S. aureus colonization were highly prevalent among HE-patients and may have an impact on the persistence of HE.

Skin Microbiome in Atopic Dermatitis.

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.

Association of Disease Severity With Skin Microbiome and Filaggrin Gene Mutations in Adult Atopic Dermatitis.

Importance: Skin microbiome correlates with disease severity for lesional and nonlesional skin, indicating a global influence of atopic dermatitis (AD). A relation between skin microbiome and filaggrin gene (FLG) mutations proposes a possible association between skin microbiome and host genetics. Objectives: To assess skin and nasal microbiome diversity and composition in patients with AD and compare with healthy controls, and to investigate the microbiome in relation to disease severity and FLG mutations in patients with AD. Design, Setting, and Participants: An observational case-control study of 45 adult healthy controls and 56 adult patients with AD was carried out from January 2015 to June 2015 in a tertiary referral center, Department of Dermatology, Bispebjerg Hospital, Denmark. Exposures: Bacterial swabs were taken from patients with AD (lesional skin, nonlesional skin, and anterior nares) and from healthy controls (nonlesional skin and anterior nares). Eczema severity was assessed and FLG mutations noted. Bacterial DNA was extracted from swabs, and V3-V4 16S rDNA regions amplified with PCR. Samples were analyzed at Statens Serum Institut September 2015 to September 2016. Bioinformatics analyses of the microbiome were analyzed using R statistical software (version 3.3.1, R Foundation Inc). Main Outcomes and Measures: Skin microbiomes were investigated using next-generation sequencing targeting 16S ribosomal RNA. Results: Microbiome alpha diversity was lower in patients with AD compared with healthy controls in nonlesional skin (effect size, 0.710; 95% CI, 0.27-1.15; P = .002), lesional skin (effect size, 0.728; 95% CI, 0.35-1.33; P = .001), and nose (effect size, 1.111; 95% CI, 0.48-0.94; P < .001). Alpha diversity was inversely correlated with disease severity for lesional (effect size, 0.530; 95% CI, 0.23-1.64; P = .02) and nonlesional skin (effect size, 0.451; 95% CI, 0.04-2.44; P = .04) in patients with AD. Microbiome composition in AD nonlesional skin was linked to FLG mutations. Conclusions and Relevance: An altered microbiome composition in patients with AD in nonlesional skin, lesional skin, as well as nose, suggests a global influence of AD. Microbiome composition in AD nonlesional skin is associated with FLG mutations, proposing a possible association between the skin microbiome and host genetics.