It is a very common phenomenon that infections are involved in the development of numerous non-infectious diseases, including allergic diseases. The development of urticaria, whether acute or chronic, is more closely related to infection. The factors of infection include viruses, bacteria, fungi, mycoplasma, chlamydia, parasites, etc. The forms of infection include acute infection, chronic infection, local infection and systemic infection. The mechanism of infection-induced urticaria is not very clear, and the value of active anti-infective therapy in relieving the symptoms of urticaria, shortening the course of the disease, and reducing recurrence is still very controversial. This article briefly discusses the relevant issues as follows. 1. Infectious factors involved in the development of urticaria The pathogenesis of urticaria involves both exogenous and endogenous factors. Some physical factors are clearly involved in the development of urticaria, drugs and food are also closely related to the occurrence of urticaria. In contrast to these factors, the role of infection in the development of urticaria is less clear, and infection is usually more insidious, so there is no clinical certainty that there is an inevitable relationship between urticaria attacks and infection. Viral infections are relatively common in children with urticaria, especially coxsackieviruses, echoviruses and other enteroviruses, which are less clinically recognized as important infectious agents, and respiratory syncytial virus and hepatitis virus have also been reported to be involved in the development of urticaria. In western developed countries, intestinal parasitic infections are not the main cause of urticaria, but may play a more important role in some specific parasitic endemic areas, such as intestinal nematodes. 2, the type of infection and the occurrence of urticaria Infection can manifest itself in different types. From the process of infection, there are acute infection, chronic infection, latent infection; from the nature of infection, there are hidden infection, subclinical infection, present infection, parasitic infection, etc. From the site of infection, there are limited infection and systemic infection, the latter includes bacteremia, toxemia, sepsis, septicemia, viremia, etc. The mechanism that triggers the body’s reaction differs from one infection to another, so the correlation with the occurrence of urticaria varies. The mechanism by which infection triggers urticaria is not well understood, and there may be a variety of activated mast cell pathways that lead to the occurrence of urticaria. Overall the mechanism of its occurrence is divided into immune and non-immune mechanisms. In addition H. pylori toxins or components act as superantigens or form antigen-antibody complexes or H. pylori mimic antigens in the body including Lewis antigens, sialylated glycol-conjugates and laminin and its residues that induce or exacerbate the inflammatory process of urticaria. Investigation found that chronic urticaria patients with H. pylori infection rate is not higher than the normal population, in vitro and in vivo studies lack direct evidence that H. pylori triggers chronic urticaria, so it is difficult to affirm the existence of an inevitable link between H. pylori infection and chronic urticaria, may only play a facilitating role in the development of some patients. 4, the clinical management of infection-induced urticaria Infection is closely related to urticaria, but is not the only key factor. The correct evaluation of the role of infection in the development of urticaria will help guide clinical work. Regarding the value of anti-infective therapy in the treatment of urticaria. Usually in patients with acute urticaria, if a viral infection is considered, antiviral therapy can be disregarded because both the viral infection itself and the urticarial process are transient and self-limiting; if it is clear that the acute urticaria is induced by a bacterial infection, especially if a clear foci of infection or positive pathogen isolation are found, antibiotics sensitive to bacteria can be considered to prevent the aggravation or spread of the infection, especially when combined with For chronic urticaria, if antihistamines are effective, even if a clear chronic infection is found to exist, anti-infective treatment can be disregarded first.