Psoriasis is a multigene genetic disease in which various factors such as genetic factors and environmental factors interact. Through a common pathway mediated by immune system, it finally causes keratinocytes to proliferate.
1. Main causes
1. Genetic factors: Psoriasis has a genetic tendency and patients have a certain susceptibility. 10% to 23.8% of domestic reports have family history, and about 30% of foreign literature have family history. There are racial differences in this disease. , black people, is rare, and Chinese people are susceptible to psoriasis is related to LCE, IL-12B, HLA-C, etc.
2. Infection factors: including bacterial infection, fungal infection, viral infection, etc. Experts have counted that 6% of patients have a history of throat infection, and among pediatric patients, those with a history of acute tonsillitis, or upper respiratory tract infection, can reach 10% to 20%. The treatment of antibiotics such as penicillin is often better.
3. Immune factors: T cell dermal infiltration is an important histopathological feature of this disease, indicating that the immune system involves the occurrence and development of this disease. It is speculated that the cytokines released by activated T cells in the skin lesions (IL-1, 6, 8 and IFN-γ, etc.) stimulate keratinocyte proliferation, promote and maintain the course of psoriasis, and Langerhans cell plays an important role in the occurrence and development of psoriasis.
4. Endocrine factors: mainly related to pregnancy, childbirth, breastfeeding and menstruation. Among adult female patients, 10% to 20% of people are related to endocrine. Some patients have reduced their condition during pregnancy and their skin lesions disappear. However, some have worsened during pregnancy or menstrual periods. The incidence rate in early childhood is relatively low, which may be related to the underdeveloped thymus in young children, and some are also believed to be related to parathyroid function.
2. Inducing factors
1. Neuropsychiatric factors: Some scholars have counted that 18.6% of patients are caused by neuropsychiatric factors. The study pointed out that neuropeptide (such as SP, CCRP and vasoactive intestinal peptides, etc.) is an important mediator in neurogenic inflammation of psoriasis. Some people speculate that it may be a mediator that psychological factors affect psoriasis.
2. Other factors: environmental factors, trauma, certain physical and chemical factors, drug stimulation and climatic factors, etc., are related to the onset of psoriasis patients. Smoking and humid living environment are the two most worthy of attention.
