The occurrence of eczematous dermatitis is associated with a variety of internal and external factors. 1. Internal factors: (1) Genetic factors: if parents are allergy-prone or are both patients with eczematous dermatitis, the probability of their children developing eczematous dermatitis is higher than that of the general population. (2) endocrine disorders: eczema dermatitis may also be triggered by recent mental stress and long hours of late night. (3) Chronic infectious lesions: chronic cholecystitis, tonsillitis, diabetes, thyroid disease patients may also develop eczematous dermatitis. 2. External causes: (1) Chemical factors: such as artificial coloring, preservatives and other food additives, yeast, alcohol, etc. These substances may irritate the skin and cause eczematous dermatitis to appear or worsen. (2) Physical factors: such as pollen, willow, animal hair and other inhaled substances may induce patients to develop eczematous dermatitis manifestations. (3) Food: such as seafood, eggs, mangoes, etc. These foods have strong antigenic properties or are prone to cause allergic reactions due to increased permeability of the digestive tract, thus causing eczematous dermatitis. There are many causes of eczematous dermatitis, it is recommended that patients do a good job of prevention on a daily basis, and if you suffer from eczematous dermatitis, you need to go to the hospital and cooperate with the doctor for standardized treatment.