Red knot rises on the body more scratch more itch is bigger how to return a responsibility

The more red lumps on the body, the more itchy it is, the more likely it is to suffer from urticaria. Urticaria is a reaction to localized skin edema due to the reactive expansion of small blood vessels in the skin mucosa, resulting in increased permeability of blood vessels. The main manifestation is that the skin currently shows red or pale itchy skin lesions with clear boundaries, called wheals. The causes of urticaria are more complex. The following are several common causes: First, food, many people may induce urticaria after eating fish, shrimp, crab or some high-protein foods. Second, drugs, there are many drugs that can cause allergic reactions in the body and cause urticaria, such as penicillin, vaccine, sulfa, etc. Third, infectious factors, such as upper respiratory tract infection or hepatitis virus, chronic infections such as sinusitis, tonsillitis can induce urticaria. In addition, there are some rare causes, such as physical factors, mental factors, and some patients will combine visceral and systemic diseases.