Adult eczema is an allergic disease caused by a variety of internal and external factors, in the clinical causes of adult eczema is not completely clear, may be related to internal factors as well as external factors, as follows: a. Internal factors: common chronic infections, such as chronic cholecystitis, tonsillitis, or have intestinal parasites and so on, as well as endocrine, metabolic changes. Some patients may be menstrual disorders, pregnancy may induce eczema. Some patients are related to blood circulation disorders, for example, many eczema in the calf area is related to varicose veins in the calf. There are also some patients with anxiety, mental stress, etc. have a relationship. The most common external factors are food allergies and allergies caused by inhalants in the air, so you can go to the hospital dermatology department to check the allergens.