So far, scientists do not know the pathogenesis of lupus erythematosus. Its main causative factors are genetics, environmental stimulation, drug influence, estrogen, etc. 1. Genetics: Lupus erythematosus has a certain relationship with genes. If someone in a family has lupus erythematosus, other members of the family are 20 times more likely to have the disease than ordinary people. If a person has a twin family member with lupus, that person is 250 times more likely to have the disease than a normal person. However, most cases do not show heritability. 2. Environment: UV rays can induce skin lesions. About 30% of lupus patients are allergic to UV rays. After sun exposure, the condition of these patients will worsen. Cold can also aggravate the disease in some patients. Some patients’ disease will be aggravated after being irritated. 3.Drugs: After some people take or inject penicillin, gold preparations and other drugs, they can stimulate lupus erythematosus or aggravate the disease in people who are already sick. 4.Estrogen: According to statistics, female patients are significantly higher than men, 9:1 in pre-menopausal stage and 3:1 in children and the elderly. To sum up, SLE is mainly caused by the above reasons, and if you suffer from this disease, you need to treat it as early as possible. With proper treatment, the disease can be effectively controlled.