Nasal Colonization by Staphylococcus aureus in Children with Atopic Dermatitis

Abstract

Background: The cutaneous and nasal microbiota, especially Staphylococcus aureus (S. aureus), plays a key role in atopic dermatitis (AD). Although this association is well known, it is difficult to establish whether colonization by these bacteria is a cause or a consequence of the disease. Objectives: The primary objectives of our study are to determine the prevalence of nasal colonization by S. aureus and its relationship with disease severity in children with AD, as well as to describe the magnitude of the association between the two. Methods: This was an analytical case-control study in children with and without AD. Participants were recruited consecutively upon presenting to the Department of Pediatric Dermatology at the General University Hospital until reaching the estimated sample size of 157 cases and 314 controls (N=471; ratio 1:2). Results: The prevalence of S. aureus nasal colonization was significantly higher in children with AD than in those without (32.5% vs. 23.9%; odds ratio (OR) 1.5, 95% CI 1.0, 2.3; p=0.047). Prevalence of colonization was not higher in the children with severe AD than in those with less severe AD. In multivariable analysis, an independent association (borderline significant) between nasal colonization by S. aureus and AD persisted after adjusting for all other study variables (OR 1.5; 95% CI 0.9, 2.6; p=0.11). Conclusions: Our paper provides further evidence of an association between atopy and nasal colonization by S. aureus, though not between nasal colonization and AD severity. The role of nasal S. aureus and the microbiota in people with AD is a controversial but crucial area of study. Greater knowledge of this topic could be clinically applicable in AD patients.