Molecular characterization of the skin bacterial communities associated with childhood eczema

Pediatric atopic dermatitis or eczema is a dermatologic condition that is increasing in prevalence in the Western world. The role played by microorganisms, specifically bacteria, in the initiation and exacerbation of this condition is not fully understood. Recent improvements in DNA sequencing technology and computational methods have made it possible to more fully characterize and analyze the composition of complex microbial communities such as those found on the human skin. We utilized DNA fingerprinting and pyrosequencing to compare the bacterial communities found at sites of eczema lesions and on uninvolved skin of infants and young children with eczema. Such analysis involving newly diagnosed patients with mild to moderate disease has the potential to identify the bacterial community dynamics associated with the early development of eczema, at a time when intervention to rescue a healthy flora may still be possible. Our results showed a decrease in community diversity at eczema flare sites as compared to healthy sites. This diversity appeared to increase in response to treatment for the eczema flare. Additionally, we found that the composition of the skin bacterial community changed with age in eczema patients as had been shown for healthy children. Finally we identified several organisms atypical of human skin that dominated the skin of these eczema patients. This data will serve as an early observational report of the variation of the human skin bacterial community associated with the early stages of eczema. The role played in eczema by these and other organisms will be better understood upon further study which should examine the functional capacities of these skin bacterial communities.