Papular urticaria is a common papulopapular skin disease in children and adolescents. It is mostly due to the bite of certain arthropods such as mosquitoes, fleas, mites, midges, bedbugs, etc. In addition, allergic constitution and gastrointestinal disorders may also be the cause of the disease. The disease occurs in the warm insect active season. It mostly occurs in children. The lesion is a 1 to 2 cm large reddish papule, slightly fusiform, with a small blister in the center, which can sometimes develop into a large blister. It often occurs in batches on the abdomen, lower back, buttocks and both lower legs, and is more clustered and less fused. If it occurs in the distal extremities, large blisters can be formed. Children have severe itching, especially at night, and often scratching leads to septic skin diseases such as impetigo, but usually no systemic symptoms. The rash gradually fades after 7-10 days, leaving pigmentation, but it can continue to occur and gradually heal after a few weeks. Patients usually have no systemic symptoms, but itching is unbearable and can easily develop secondary infectious diseases such as impetigo. Generally older (7-8 years old) can reduce symptoms and stop occurring. Prevention and treatment: Improve environmental, room and personal hygiene, dry bedding regularly, and avoid contact with animals such as dogs and cats to eliminate the breeding of insects that cause this disease. Insecticides can be sprayed indoors and outdoors to eliminate bedbugs, fleas, mosquitoes and other harmful arthropods. If the rash is large, go to the hospital promptly.