Multipolarity of cytokine axes in the pathogenesis of atopic dermatitis in terms of age, race, species, disease stage and biomarkers.

Atopic dermatitis (AD) is a common T-cell-mediated inflammatory disease of the skin. Signatures of AD are characterized by an impaired skin barrier, aberrant Th2-type cytokine production and intensive pruritus. Transcriptomic analysis, however, has revealed a heterogeneous pathogenesis and the co-existence of multiple cytokine axes of Th17, Th22 and Th1 types, especially in intrinsic (a subtype of AD without skin barrier impairment), pediatric and Asian types of AD. Furthermore, the therapeutic effect of anti-IL-4 receptor α against AD was not as high as that of IL-17 blockage against psoriasis, which implies a modification of the disease spectrum by non-Th2-type cytokine axes in AD. These lines of evidence indicate a need for personalized or precision medicine appropriate for each subtype of AD.