Chronic inflammatory skin diseases (i.e., atopic dermatitis) are known to increase the expression of Th2 cytokines (i.e., IL-4, IL-5, and IL-13) in peripheral blood.[15] As such, Th1/Th2 immune balance can be a very important indicator for itching, and we aim to analyze the changes in cytokines associated with Th1/Th2 immune responses to investigate the mechanism of action of Sopoongsan on chronic itching. Here, IL4 is linked to atopic eczema.