IL4 and inflammatory skin disease: AD is a highly heterogeneous inflammatory skin disease with complex pathophysiological mechanisms, the core of its immunological mechanism lying in the imbalance of Th1/Th2 cells, which triggers a series of complex inflammatory responses.[6,34] Langerhans cells and inflammatory dendritic cells in the skin recognize and present allergens, activating Th2 cells to secrete cytokines such as IL-4, IL-5, and IL-13.[35,36] These factors further stimulate inflammatory cells, leading to localized skin inflammation.