IL4 and Alzheimer disease: The prevalence of atopic dermatitis (AD) is increasing worldwide.1 AD can be caused by numerous etiological factors,2,3 and typically characterized by the T helper (Th)2-dominated immune response.4 For example, IL-4, a key cytokine involved in atopic inflammation, is secreted from mast cells and drives the differentiation of T helper cells into Th2 cells.