Psoriasis, also known as , is a common chronic recurrent inflammatory skin disease. What factors are associated with the occurrence and development of psoriasis then? In fact, so far, a lot of research has been done at home and abroad on the causes or triggers of psoriasis, but so far it is not very clear, it may be related to the following: 1, genetic factors: some patients have a family gathering phenomenon, some families have a clear genetic tendency, the prevalence of identical twins is 63%, these show that genetic factors are very important in the etiology of the disease. It is generally believed that those with a family history account for about 20-30%; of course, most patients have no family history, so why do they suffer from psoriasis? Because psoriasis is due to a combination of genetic factors and environmental factors and other factors; 2, abnormal immune function: a large number of studies show that psoriasis is an immune-mediated inflammatory skin disease, and its pathogenesis is related to inflammatory cell infiltration and inflammatory factors, and the current application of biological agents for the treatment of psoriasis is effective, which also shows that inflammatory factors and other factors are involved in the development of psoriasis. 3, infection: infection (including bacterial infection, viral infection, fungal infection) has been considered the main factor that promotes or aggravates psoriasis; for example, there is often a history of acute streptococcal infection of the pharynx before the onset of punctate psoriasis, and the condition often improves after antibiotic treatment is given; infection can transform common psoriasis to pustular psoriasis and erythrodermic psoriasis and aggravate the condition; 4, environmental factors and living habits: cold 5, drug factors: such as β1 receptor blockers (such as metoprolol, atenolol, etc.), non-steroidal anti-inflammatory drugs (such as indomethacin, ibuprofen, meloxicam, etc.), calcium channel blockers (nifedipine, etc.), lithium salts, antimalarial drugs, tetracycline, metformin, etc. 6, psychoneurological factors: mental tension, anxiety may affect the nervous, endocrine, immune system, and aggravate the disease. 7, endocrine factors: such as pregnancy, childbirth, etc. During pregnancy, psoriasis often has the tendency to improve, while after delivery, there is a tendency to aggravate.