Cetirizine for children is usually taken for about 1 week to half a month, and the maximum number of days varies depending on individual conditions. Cetirizine is an anti-allergy drug that can effectively treat and relieve allergy symptoms, and is commonly used for seasonal or perennial allergic rhinitis, dermatitis, conjunctivitis, asthma, urticaria and itchy skin. It is usually taken once a day for about 2-3 days after the allergy symptoms disappear, and the specific duration of the medication should be decided by the doctor according to the patient’s condition. Secondly, once the allergic symptoms appear, patients should first try to avoid contact with allergens, and it is recommended to go to the hospital for examination and diagnosis in a timely manner, and follow the doctor’s instructions to treat the drug on time and in accordance with the dosage, not to take the drug blindly. In addition, cetirizine should not be taken in large quantities for a long time to avoid headache, dry mouth, nausea and drowsiness. Also, patients should avoid spicy and oily food during the medication period.