The causes of anal eczema are complex, and the causes are as follows: (1) Anal diseases: such as hemorrhoids, anal fistula, anal fissure, anal incontinence, epithelial defects of the anal canal, etc. (2) Physical factors: It is believed that poor quality has an important relationship with this disease. (3) Dietary factors: fish, shrimp, crab, beef and mutton, eggs, onion, garlic, wine, etc. (4) Drug influence: sulfonamides, certain antibiotics and strong acids, strong bases and other chemicals. (5) mental factors: mental tension, fatigue, depression, insomnia can also cause. (6) Allergens: such as pollen, dust, wool, artificial fiber, balsam, dyes, soap, etc. (7) Disease factors: such as endocrine disorders, liver and kidney dysfunction, intestinal parasitic diseases, digestive disorders, leucorrhea in women, enchanting disease, etc., can cause or aggravate the condition. (8) Other: heat, humidity, cold, sunlight and other climatic influences are also causative factors.