Skin Disease

Internal cause: 

As the body's first physiological defense line and the largest organ, the skin is always involved in the functional activities of the body, maintaining the unity of the body and the natural environment. Any abnormality of the body can also be reflected on the surface of the skin. 

For example: psoriasis, psoriasis, vitiligo, allergic pruritus, lupus erythematosus, visceral cancer, skin manifestations, etc., are not only with cell division abnormalities, pathogenic microbial infections and their production of toxins, metabolic disorders, and even with the spirit, The pathological changes in the nervous system have an indirectly or directly.

External factors: 

mechanical: such as sputum, rubbing erythema, trauma and so on. Physical: such as frostbite, burns, sunburn, radiation dermatitis, etc. 

Chemical: Most contact dermatitis is caused by exposure to chemicals such as dyes and chemical raw materials.