A population-based cohort study in 1,079 postnatal Dutch infants studied the association between Staphylococcus aureus nasal colonization and atopic dermatitis (AD) development in infancy. Nasal swabs for S. aureus were obtained at 1.5, 6 and 14 months of age. The outcome was development of AD in the first and second year of life. A positive S. aureus culture at 6 months was associated with AD prevalence in the first and second year of life (adjusted odds ratio [aOR]: 2.13 and 2.88, respectively; P < 0.05). It was also correlated with severity of AD (aOR: 3.27). Frequent (2 times or more) colonization in the first year of life held a higher ...