Nowadays, medicine has evolved and specialties are getting more and more subdivided, and physicians only care about their own specialties. In the case of dermatology, physicians are only concerned with stopping itching and eliminating rashes, and people rarely care whether the body is accompanied by other diseases in addition to rashes and itching. In fact, the human body is a complete individual, closely connected to each other, and skin lesions are also a signal that the body is diseased. Many diseases have skin manifestations, such as discoid erythema in SLE, butterfly erythema, rheumatic nodules in rheumatic fever, gout nodules in gout disease, and skin lesions in lymphoma. Some skin diseases also combine with visceral damage; common urticaria can have gastrointestinal symptoms and damage, waves of larynx can also suffocate and die, and erythema nodosum can combine with kidney damage. Many infectious diseases enter the body through the skin causing serious lesions and damage, such as leptospirosis, pulmonary schistosomiasis, syphilis, acromegaly and other diseases. Cheng Xiping, Department of Dermatology, The First Hospital of Guangzhou Medical University The skin of a normal person can reflect the state of the organism, young people, the color of the skin is white and red, 70 or 80 years old woman’s skin is full of folds. Nevertheless, people do not easily make the connection with internal damage for skin diseases. Studies have shown that in patients with skin disease of more than 3 months, routine urine examination is performed and 67% of patients will have urinary occult blood, most of them have abnormal red blood cells in the urine, reflecting damage to the glomeruli of the kidneys. On further examination, indicators of immune disorders such as decreased complement and, in some cases, autoantibodies, will be present. Further clinical studies have found that dermatologic disease can be combined not only with renal damage but also with pulmonary damage, and a simple chest radiograph reveals that interstitial lung changes are present in many patients with dermatologic disease, and that the severity correlates with the severity of the dermatologic disease. This actual presence of visceral damage has certain clinical features; most of the visceral damage is relatively mild and usually has no obvious clinical manifestations. Many internal diseases are called primary diseases and are diagnosed only when there are symptoms. In fact, many of them can be detected at an early stage, and we have found many patients with early nephritis by examining the urine of dermatologic patients, and through treatment we are able to control the further development of nephritis.