What are the common causes of skin diseases?

The common causes of skin diseases are diverse and mainly include: 1. Infectious factors: such as infections by microorganisms including viruses, bacteria, fungi, and parasites. These pathogens can cause different types of skin diseases, such as herpes, scabies, and athlete's foot. 2. Physical and chemical factors: including pressure, friction, temperature changes, radiation, chemicals. For example, long-term exposure to irritating chemicals or allergens may lead to contact dermatitis, while excessive exposure to sunlight may trigger solar dermatitis. 3. Genetic factors: some skin diseases are hereditary, such as ichthyosis and albinism. The occurrence of these diseases is closely related to the individual's genetic characteristics. 4. Immunological factors: when the body's immune system reacts abnormally, it may trigger autoimmune skin diseases, such as lupus erythematosus and dermatomyositis. These diseases can cause tissue damage and physiological dysfunction. 5. Other factors: age, gender, occupation, season, personal hygiene status, and psychological factors may also influence the development of skin diseases. For example, the weakened skin barrier function in the elderly makes them more susceptible to skin diseases, while excessive mental stress may trigger or exacerbate certain skin conditions.