Histamine human immunoglobulin also means histamine human immunoglobulin. The itching of the skin after half a month of playing histamine human immunoglobulin may be related to the adverse reaction of the drug or to the factors of the disease itself. 1. Adverse reaction of the drug. Histamine Human Immunoglobulin Injection belongs to a kind of biological products, its main component is histamine human immunoglobulin, and the excipients are sodium thiosulfate and anhydrous glucose. Adverse reactions to the drug are extremely rare, and a very small number of people may experience itching of the skin or even induce an attack of urticaria. 2. Factors of the disease itself. The main effect of histamine human immunoglobulin injection is to stimulate the body to produce anti-histamine antibodies and enhance the body’s immunity, so it is often used in the prevention and treatment of various allergic diseases. Itchy skin is the most frequent symptom of allergic skin diseases, and itchy discomfort may reappear before the disease is cured. Since itchy skin is a subjective feeling, and there are obvious individual differences, the specific situation needs to be analyzed after a doctor’s consultation and in combination with other clinical manifestations.