Papular urticaria, also known as acute simple itchy rash, is a common papular skin condition that occurs in children and adolescents and is associated with intense pruritus. The main causes include arthropod bites such as mosquitoes, fleas, mites, etc.; food allergies, gastrointestinal disorders, and teething-related. The disease mainly occurs in the warm season, and is more common in spring, summer and autumn. Children and adolescents are prone to the disease, but it can also occur in middle-aged and elderly people. They often appear as intensely itchy, slightly fusiform bright red papules with small central blisters or blisters, occurring in groups, mostly on the waist, abdomen, back, buttocks and both lower legs, in clusters or stripes. When the erythema and edema have subsided, a hard papule remains. The duration of the disease is about 7-10 days, and pigmentation may remain after healing. When there is secondary infection, there may be fever and swollen lymph nodes. In general, it is not difficult to diagnose the disease based on the typical papules that occur on the back and extremities of children, with small blisters on the top, intense itching, and mostly no systemic symptoms. However, care should also be taken to differentiate it from urticaria and chickenpox, for example, chickenpox, which also has blisters, but the blisters are umbilical fossa-shaped. Therefore, if there is discomfort, it is also necessary to seek medical attention for a clear diagnosis.