Children with Atopic Dermatitis Appear Less Likely to Be Infected with Community Acquired Methicillin-Resistant Staphylococcus aureus: The San Diego Experience

Given the increasing rate of community-acquired methicillin resistant Staphylococcus aureus skin infections in the population, such infections might be concurrently increasing in patients with atopic dermatitis. This study assessed current and prior rates of community-acquired methicillin resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus skin and soft tissue infections in children with atopic dermatitis compared to the general pediatric population. Other antibiotic sensitivity and resistance patterns, including clindamycin-inducible resistance, were also identified. Retrospective study of all skin and soft tissue isolates were positive for Staphylococcus aureus during two distinct 1-year periods, obtained by the outpatient services and the emergency department at Rady Children's Hospital, the major regional pediatric health center in San Diego, California. Of the Staphylococcus aureus isolates obtained from January to December 2000, none from atopic dermatitis patients were methicillin resistant Staphylococcus aureus, while 4.2% of those obtained from the general outpatient pediatric population showed methicillin resistance. In the period from June 2007 to May 2008, 11 of 78 isolates (14.1%) from children with atopic dermatitis were methicillin resistant Staphylococcus aureus. This was significantly lower than the rate of increase noted in the general pediatric population (658 of 1482, or 44.4%, in 2007/2008, p < 0.05). Clindamycin-inducible resistance was noted in 1.9% of the isolates in the general population; all six tested isolates from atopic patients lacked clindamycin-inducible resistance. In this study, children with atopic dermatitis had a much lower rate of community-acquired methicillin resistant Staphylococcus aureus infection compared to the general outpatient pediatric population. Clindamycin-inducible resistance was very low in both groups.