chosen by dermatology Dermatology is the science of studying skin and its related diseases. Its content not only includes the structure and function of normal skin and appendages, but also covers the etiology, pathogenesis, clinical manifestations, diagnosis, treatment and prevention of various skin and appendage related diseases. Development history Before the middle of the 18th century, the diagnosis and treatment of dermatology were generally undertaken by surgeons, and the knowledge about dermatology was also included in the textbooks of surgery; At the end of the 18th century, many physicians began to pay attention to observing and recording skin diseases. This trend continued until the 19th century, which gradually developed dermatology into a branch of internal medicine; At the end of the 19th century, the study of Treponema pallidum and Mycobacterium tuberculosis infection became a relatively independent category in internal medicine; In the early 20th century, some physic...