Atopic dermatitis (AD) is the most common inflammatory skin disorder in the general population worldwide, and the majority of patients are colonized with Staphylococcus aureus. Eczema herpeticum is a disseminated herpes simplex virus infection that occurs in a small subset of patients.

The goal was to conduct proteomic profiling of patients with AD based on S aureus colonization status and history of eczema herpeticum. We hoped to identify new biomarkers for improved diagnosis and prediction of eczema herpeticum and S aureus susceptibility and to generate new hypotheses regarding disease pathogenesis.

Skin taping was performed on nonlesional skin of nonatopic control subjects and on lesional and nonlesional skin of patients with AD. Subjects were classified according to the history of eczema herpeticum and S aureus colonization. Proteins were analyzed by using mass spectrometry; diagnostic groups were compared for statistically significant differences in protein expression.

Proteins related to the skin barrier (filaggrin-2, corneodesmosin, desmoglein-1, desmocollin-1, and transglutaminase-3) and generation of natural moisturizing factor (arginase-1, caspase-14, and gamma-glutamyl cyclotransferase) were expressed at significantly lower levels in lesional versus nonlesional sites of patients with AD with and without history of eczema herpeticum; epidermal fatty acid–binding protein was expressed at significantly higher levels in patients with methicillin-resistant S aureus.

This noninvasive, semiquantitative profiling method has revealed novel proteins likely involved in the pathogenesis of AD. The lower expression of skin barrier proteins and enzymes involved in the generation of the natural moisturizing factor could further exacerbate barrier defects and perpetuate water loss from the skin. The greater expression of epidermal fatty acid–binding protein, especially in patients colonized with methicillin-resistant S aureus, might perpetuate the inflammatory response through eicosanoid signaling.