The role of bacterial skin infections in atopic dermatitis: expert statement and review from the International Eczema Council Skin Infection Group

Abstract

Patients with atopic dermatitis (AD) have an increased risk of bacterial skin infections, which cause significant morbidity and, if untreated, may become systemic. Staphylococcus aureus colonizes the skin of most patients with AD and is the most common organism to cause infections. Overt bacterial infection is easily recognized by the appearance of weeping lesions, honey-coloured crusts and pustules. However, the wide variability in clinical presentation of bacterial infection in AD and the inherent features of ADcutaneous erythema and warmth, oozing associated with oedema, and regional lymphadenopathyoverlap with those of infection, making clinical diagnosis challenging. Furthermore, some features may be masked because of anatomical site-and skin-type-specific features, and the high frequency of S. aureus colonization in AD makes positive skin swab culture of suspected infection unreliable as a diagnostic tool. The host mechanisms and microbial virulence factors that underlie S. aureus colonization and infection in AD are incompletely understood. The aim of this article is to present the latest evidence from animal and human studies, including recent microbiome research, to define the clinical features of bacterial infections in AD, and to summarize our current understanding of the host and bacterial factors that influence microbial colonization and virulence. The role of bacterial skin infections in atopic dermatitis, H. Alexander et al. 1335 Fig 6. Hypothetical damage-response framework for Staphylococcus aureus in atopic dermatitis (AD). 82 Different host-S. aureus interactions result in different damage-response relationships. Curves A and B represent the damage-response relationships of S. aureus with two different hosts or those of a single host with two different S. aureus strains. The outcome for the host depends on the strength of the host response to S. aureus or the virulence of S. aureus. During intermediate host responses neither interaction (A or B) causes clinical evidence of infection, as the amount of damage incurred by the host is insufficient (1). However, in the setting of weak or strong responses both interactions cause an AD flare (2) and interaction B causes overtly infected AD (3). The position of the curve is determined by multiple host and S. aureus factors.

Simultaneous profiling and cultivation of the skin microbiome of healthy young adult skin for the development of therapeutic agents

“…Age and sex also plays important role in variability of skin microbiota compositions, as described in skin microbiota survey on Chinese, Finnish, and Brazilian populations [38,39,40]. Diseased skin in particular, e.g atopic dermatitis (AD), leprosy, and hidradenitis suppurativa (HS) conditions are characterized by apparent changes in skin microbiota composition, such as underrepresentation of Firmicutes and increase in Proteobacteria for leprosy patients and appearance of genus Porphyromonas and Peptoniphilus in HS patients [39,41,42]. Unique microbial activities and communities on different populations may serve valuable information to target diseases based on predictive models, or utilized beneficial health purposes [43,44].…”

The infectious complications of atopic dermatitis

“… 28 However, apart from the outcome of AD severity, there may be a subset of patients with severe AD exacerbation who may benefit from antibiotics in terms of infections or the prevention of infectious complications. 4 , 28 , 29 It has been proposed that these patients may be differentiated by a higher density of S aureus and the amount of tissue damage caused by S aureus –host interaction. 29 Children with severe AD exacerbation were found to have elevated C-reactive protein and erythrocyte sedimentation rate, although these levels were significantly less than that of patients with infectious complications.…”

“… 4 , 28 , 29 It has been proposed that these patients may be differentiated by a higher density of S aureus and the amount of tissue damage caused by S aureus –host interaction. 29 Children with severe AD exacerbation were found to have elevated C-reactive protein and erythrocyte sedimentation rate, although these levels were significantly less than that of patients with infectious complications. 4 There may be a potential use in these inflammatory markers in identifying patients with AD who are at risk for severe infectious complications.…”

Bacteriological Quality of Borehole and Sachet Water from a Community in Southeastern Nigeria

“…The bacterium is a major environmental contaminant of food and water, and the human skin and nose are known to be major sources of the organism. Nasal colonization [67,68] and atopic dermatitis of the skin [69,70] are considered risk factors. Environmental contamination may be the source of contamination in borehole water analyzed in this study, whereas humans or personnel involved in sachet water production are likely to be contributors to contamination.…”