Allergic skin inflammation and S. aureus skin colonization are mutually reinforcing.

Atopic dermatitis (AD) lesional skin is often colonized with S. aureus, and the load of S. aureus correlates with disease severity. However, a causative and mechanistic link between S. aureus skin colonization and severity of AD is not well established. We made use of well-established mouse model of AD elicited by epicutaneous sensitization of tape stripped skin with ovalbumin to investigate the relationship between allergic skin inflammation and cutaneous S. aureus colonization. Topical application of S aureus exacerbated allergic skin inflammation induced by epicutaneous sensitization with ovalbumin, whereas allergic skin inflammation generated a permissive environment for S. aureus persistence. Our results establish a mutually reinforcing role of allergic skin inflammation and S. aureus skin colonization.