A considerable number of patients have family history, and some families have obvious genetic tendencies. It is generally believed that people with family history account for about 30%. The incidence varies greatly between different races. Psoriasis is a polygenic genetic disease in which genetic factors and environmental factors interact. The incidence of some HLA antigens in patients with this disease increased significantly. Genetic loci of psoriasis and other diseases such as rheumatoid arthritis and atopic dermatitis. ) may overlap.
2. Influence
Many scholars have confirmed that streptococcal infection is related to the onset and prolonged course of psoriasis from humoral immunity (anti-streptococcal group), cellular immunity (peripheral blood and T cells in lesions), bacterial culture and treatment. Staphylococcus aureus infection in patients with psoriasis can aggravate skin lesions, which is related to the superantigen of Staphylococcus aureus exotoxin. Although the occurrence of this disease is related to the infection of viruses (such as HIV) and fungi (such as Malassezia), its exact mechanism has not been finally confirmed.
3. Immune abnormality
A large number of studies have proved that psoriasis is an immune-mediated inflammatory skin disease, and its pathogenesis is related to inflammatory cell infiltration and inflammatory factors.
4. Endocrine factors
Some female patients' skin lesions relieved or even disappeared after pregnancy, and worsened after delivery.
5. Others
Psychoneurological factors are related to the pathogenesis of psoriasis. Alcohol, smoking, drugs and mental stress can all induce psoriasis.