Prevalence and odds of Staphylococcus aureus carriage in atopic dermatitis: a systematic review and meta-analysis

Background Staphylococcus aureus is increasingly implicated as a possible causal factor in the pathogenesis of atopic dermatitis (AD). However, the reported prevalence rates of skin and nasal colonization in the literature vary widely. Objectives This study evaluates the prevalence and odds of skin and nasal colonization with S. aureus in patients with AD. Methods A systematic literature search was conducted. Odds ratios (ORs) for colonization in patients vs. controls and the prevalence of colonization in patients were pooled using the random-effects model. Results Overall, 95 observational studies were included, of which 30 had a control group. The Newcastle-Ottawa Scale was used to assess study quality, with the majority of studies being of fair to poor quality. Patients with AD were more likely to be colonized with S. aureus than healthy controls [OR 19 +/- 74, 95% confidence interval (CI) 10.88-35.81]. Differences were smaller in nonlesional skin (OR 7.77, 95% CI 3.82-15.82) and in the nose (OR 4.50, 95% CI 3.00-6.75). The pooled prevalence of S. aureus colonization among patients was 70% for lesional skin, 39% for nonlesional skin and 62% for the nose. In lesional skin, meta-regression showed that the prevalence of colonization increased with disease severity. Study heterogeneity should be taken into consideration when interpreting the results. Conclusions These results demonstrate the importance of colonization with S. aureus in AD. Further evaluation of the mechanisms by which S. aureus influences inflammation is required in addition to the development of targeted strategies to decrease skin and nasal S. aureus load.