The general disappearance of urticaria in children in a few days depends mainly on the type of urticaria, and the exact time of its disappearance varies from person to person and cannot be generalized. In the case of acute urticaria in children, it is common to see allergic urticaria and infective urticaria. For children with allergic urticaria, the allergen needs to be removed and treated with oral antihistamines, and the rash can usually disappear after 1-2 days. For children with infectious urticaria, if the infection is caused by bacteria, the rash can usually subside in 3-5 days after the application of antibiotics and anti-allergy medication, and then the rash can be cured after 3-5 days of consolidation treatment; if the infection is caused by virus, the rash will disappear in about 1 week; if the infection is caused by parasites, the rash can also improve faster after deworming treatment. In the case of chronic urticaria, it may take at least several months of continuous medication to heal, and may even take more than six months. If hives appear in children, it is recommended to go to the pediatric dermatology department of a regular hospital in a timely manner and undergo targeted treatment after examination to clarify the cause.