The cause of eczema is still unclear, it is an inflammatory disease of the superficial dermis and epidermis caused by internal and external factors, and can be divided into internal and external factors. 1. Internal factors: common are chronic infectious diseases, such as chronic cholecystitis, tonsillitis, intestinal parasites; or patients with endocrine disorders, such as menstruation, pregnancy, polycystic ovary syndrome, etc.; or patients with long-term mental tension. At the same time, eczema also has a certain relationship with genetic factors. 2. External factors: common external factors include eating allergens (such as fish, shrimp, beef, lamb, etc.), inhaling allergens (such as pollen, dust, etc.) or contacting allergens (such as animal fur, cosmetics, skin care products, etc.), and may also be related to the external environment of the hot, dry air and other factors. The occurrence of eczema is related to the interaction of various internal and external factors, and it is recommended that patients go to regular hospitals in time for examination and standardized treatment under the guidance of doctors after clarifying the causes of the disease.