When AD occurs, scratching of the skin due to itching causes severe damage to the epidermal barrier of the skin followed by dysregulation of immunoregulatory proteins, such as interleukin (IL)-1, IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), in skin epithelial cells (3, 4). This evidence concerns the gene TSLP and Alzheimer disease.