Staphylococcus aureus colonization in atopic dermatitis and its therapeutic implications.

Skin colonization with Staphylococcus aureus is a characteristic feature of atopic dermatitis with more than 90% of patients being colonized. Extracellular matrix proteins are important for the adherence of S. aureus to human keratinocytes. The bacterium interferes in the inflammatory process of atopic dermatitis in various ways, among which the ability to release superantigens in a high percentage of clinical isolates is of great importance. As the colonization correlates significantly with the severity of eczema, anti-staphylococcal treatment measurements are widely used. In cases of atopic dermatitis exacerbation with wide-spread weeping lesions, a systemic antibiotic treatment is warranted, with erythromycin no longer being recommended due to an increased resistance rate. In localized superinfected lesions the topical application of an antibiotic-glucocorticoid preparation may offer advantages to the mere steroid application. Based on efficacy and resistance data, fusidic acid is the antibiotic of choice. There is evidence that phototherapy in atopic dermatitis may be even more effective when combined with anti-staphylococcal measurements. In the future new therapeutical options may be available.