Urticaria, commonly known as rubella, is a limited edema of the skin mucosa due to a temporary increase in vascular permeability. Recurrent episodes of spontaneous rash and angioedema for more than 6 weeks and at least twice a week are called chronic urticaria. Most patients with chronic urticaria cannot find the exact cause, and common causes include food, infection, drugs, and physical factors. Foods such as fish, shrimp, crab, eggs, etc. are common. Infections such as coxsackie virus, hepatitis virus), fungi and parasites. Drugs can cause the disease, such as penicillin antibiotics, serum preparations, various vaccines, etc. There are other factors, such as cold, heat, sunlight, friction and stress factors. Common manifestations: Localized itching or tingling sensation on the skin and rapid appearance of rash before the appearance of rubella masses. Some patients develop systemic symptoms, such as lack of appetite, general malaise, headache or fever, within a few hours or one to two days of the appearance of rubella masses. Many patients have a rash that occurs daily, or recurs or worsens, remits or disappears intermittently for months or years, called chronic urticaria. The cause of chronic urticaria is complex, the pathogenesis is not clear, treatment is more difficult and the course of treatment is long, it is recommended to systematically standardize treatment.