The duration of acute urticaria in children is usually about 2~4 weeks at the longest. Pediatric urticaria, from the onset of time, is divided into acute urticaria and chronic urticaria, of which acute urticaria mainly refers to the onset of urticaria in about 2~4 weeks. Chronic urticaria usually refers to urticaria with a continuous duration of more than 6 weeks. From the treatment of acute urticaria, after the removal of allergens and then symptomatic treatment, the symptoms can usually be relieved in a few hours to a few days, if the symptoms persist or recur for more than 6 weeks, it can be diagnosed as chronic urticaria. In order to avoid the transformation of acute urticaria to chronic urticaria, children with acute urticaria need to remove the causative factors and medication: 1. Removing the causative factors is mainly to improve the allergen test as soon as possible, and then clarify the cause of allergy, avoid re-exposure, in order to minimize the recurrence of urticaria. 2. Drug treatment is mainly targeted to give antihistamines to relieve the symptoms of urticaria, can be used topically or orally, such as cetirizine hydrochloride syrup, loratadine granules and so on.