Eczema is an inflammatory skin disease with a pronounced tendency to exude caused by a variety of internal and external factors, accompanied by pronounced itching and prone to recurrence, which seriously affects the quality of life of patients. The etiology of eczema is not yet clear. Endogenous causes include abnormal immune function (e.g., immune imbalance, immunodeficiency, etc.) and systemic diseases (e.g., endocrine diseases, nutritional disorders, chronic infections, tumors, etc.) as well as hereditary or acquired skin barrier dysfunction. External factors such as environmental or food allergens, irritants, microorganisms, changes in ambient temperature or humidity, and sun exposure can trigger or aggravate eczema. Psychosocial factors such as stress and anxiety can also trigger or aggravate the disease. The pathogenesis of this disease is not clear. At present, it is mostly believed to be the result of a combination of internal and external factors based on internal factors such as abnormal immune function and skin barrier dysfunction. Both immune mechanisms such as allergic reactions and non-immune mechanisms such as skin irritation are involved in the pathogenesis. Microorganisms can trigger or exacerbate eczema through direct invasion, superantigenic action or induction of an immune response.