Individual clusters of allergic urticaria usually last no more than 24 hours, and the overall time it takes to clear up depends on the specific type. Acute spontaneous urticaria usually clears up in 1 to 2 weeks. Chronic urticaria may take 3~4 months or even years to subside, and active treatment can promote recovery. 1. Allergic urticaria can make the patient suddenly itchy skin, and soon appear red or pale-white lumps of different sizes and shapes, so that the skin surface is uneven, with an orange peel-like appearance. The duration of a single mass is usually less than 24 hours, but new masses will continue to rise, one after another, and how long it takes for the whole to subside is related to the specific type. 2. Acute spontaneous urticaria, if caused by viral or bacterial infections, after the cause of the disease is clear and symptomatic treatment, usually 1~2 weeks can completely subside. Chronic urticaria, the onset of which lasts more than 6 weeks, may take 3 to 4 months or even years to subside. Patients need to take oral antihistamine and anti-allergy drugs as prescribed by the doctor to promote the recovery of the condition. When allergic urticaria occurs, it is recommended to go to the hospital in time and standardize the treatment under the guidance of the doctor, so as not to delay the condition.