Neurodermatitis is a chronic skin inflammation caused by neurological dysfunction, which is characterized by paroxysmal severe phlegm itching and skin covering. Because its skin surface is rough, its texture is deepened, its shape is like moss, and it is as hard as cow neck skin, so it is called psoriasis. There is no exudation in the medical history and it is easy to relapse.

According to the range of incidence, the disease can be divided into two types: localized and systemic. At the beginning of the disease, the skin itches. After scratching or rubbing, a patch papule of millet to mung bean size appears, and the top is flat and polygonal, which can form a typical patch with reddish, yellowish brown or normal skin color and covered with scales. Consciously paroxysmal severe phlegm itching, especially at night, the course of disease is slow, and it is easy to recur after many years. The rash is mostly confined to the back of the neck, elbow fossa, popliteal fossa and functional tail, which is called localized neurodermatitis. If it spreads all over the body and is widely distributed, it is called generalized neurodermatitis.