Acute urticaria is not necessarily a result of poor immunocompetence, but immunocompromise is a cause of acute urticaria. Acute urticaria is a vasovagal allergic reactive disease with a complex pathogenesis, which is categorized into endogenous and exogenous factors depending on the source. Endogenous factors mainly include infections (viral, bacterial or fungal, parasitic infections), mental overstress, depression, low immunity, and underlying diseases. Exogenous factors include food, drugs, implants, inhalants, and physical factors such as heat and cold, sunlight, and friction. Due to the many factors involved in the development of urticaria, the specific cause needs to be analyzed in conjunction with the rest of the medical history, and for those who are immunocompromised, immune modulation can be performed under the guidance of a doctor.