Urticaria is commonly known as rubella. It is a limited edematous reaction due to dilatation of small blood vessels in the skin and mucous membranes and increased permeability, which usually subsides within 2 to 24 hours, but new rashes occur repeatedly. The course of the disease is prolonged for several days to several months. It is more common in clinical practice. The causes of urticaria a. Food irritation Common irritating foods are fish, shrimp, crab, eggs, etc., and then some meat and some plant foods, such as cocoa, strawberries, garlic or tomatoes, or some other condiments. Some people may get hives after consuming some irritating foods, which can be considered as allergic reactions. However, some unfresh foods will be broken down into peptides, and alkaline peptide substances belong to is histamine releasing substances, which will be absorbed by the body in the form of peptones or peptides before the protein foods are thoroughly digested by the gastrointestinal tract, thus leading to hives. In addition, food additives such as colors, flavors and preservatives are also some of the more common allergic substances, sensitive people consumed, may lead to the onset of urticaria. Second, drug stimulation Some drugs may also trigger urticaria due to the body’s different constitution, many kind drugs also tend to trigger the body’s metabolic reactions, resulting in the development of urticaria, common drugs with stimulating effects are a variety of immobile vaccines, dysentery, penicillin, serum preparations, sulfonamide, etc.. Some of the benevolent drugs such as: morphine, codeine, aspirin, hydrazidazine, etc. belong to histamine release, for people with physical allergies, may also be stimulated, thus leading to the disease. Infection factors Infection factors are also divided into many kinds, including viral infections, fungal infections, bacterial infections and parasitic infections and so on. The most common is the infection factor is the virus that causes upper respiratory tract infections and another kind of Staphylococcus aureus infection, and then there is the hepatitis virus, which is also a relatively common infection virus. Patients with chronic infectious lesions, such as tonsillitis, sinusitis, chronic otitis media, etc., all of these diseases have a superb relationship with the development of urticaria, which is difficult to determine simply and can only be conclusively proven by treatment and experimentation.