IL13 and Alzheimer disease: Recent studies have shown that eosinophils and mast cells are the most important effector cells in AD, releasing inflammatory mediators, such as histamine, leukotrienes, and cytokines (IL-3, IL-4, IL-5, and IL-13), which ultimately leads to itching and skin lesions, which are characteristic of AD (Raap et al., 2006; Lam, 2010).