Methicillin-resistant Staphylococcus aureus (MRSA) colonization in Atopic Dermatitis (AD) patients can contribute to worsening their clinical condition.

A cohort study was carried out to determine the incidence of MRSA acquisition and its risk factors in AD children.

Patients with AD (2 months–14 years old) were followed up for about 1 year at a reference center for AD treatment in Rio de Janeiro, Brazil, from September 2011 to February 2014. Nasal swabs from patients and contacts were collected every 2 months. The SCORAD system assessed the severity of the AD. S. aureus isolates were evaluated to determine the methicillin resistance and the clonal lineages.

Among 117 AD patients, 97 (82.9%) were already colonized with S. aureus and 26 (22.2%) had MRSA at the first evaluation. The incidence of MRSA acquisition in the cohort study was 27.47% (n = 25). The SCORAD assessments were: mild (46.15%), moderate (37.36%) or severe (16.48%). Risk factors were: colonized MRSA contacts (HR = 2.27; 95% CI: 1.16–7.54), use of cyclosporine (HR = 5.84; 95% CI: 1.70–19.98), moderate or severe AD (HR = 3.26; 95% CI: 1.13–9.37). Protective factors were: availability of running water (HR = 0.21; 95% CI: 0.049–0.96) and use of antihistamines (HR = 0.21; 95% IC: 0.64–0.75). MRSA isolates carried the SCCmec type IV and most of them were typed as USA800/ST5.

The high incidence of MRSA acquisition found among AD patients and the risk factors associated show that an effective surveillance of MRSA colonization in these patients is needed.