The effect of loratadine is usually seen after 30 minutes of administration and reaches its maximum concentration in 8-12 hours for maximum effectiveness. Loratadine is a second-generation antihistamine and is a commonly used anti-allergy drug with highly effective and long-lasting effects. The dosage is 1 tablet once a day. To avoid adverse reactions such as headache, drowsiness and dry mouth, patients are advised to take it orally in the evening. This drug is indicated for various allergic skin diseases and can also be used for other pruritic skin diseases, and symptoms can be relieved quickly after taking the drug orally. At the same time, patients should avoid re-exposure to allergens during treatment with loratadine, and treatment should be based on symptom control, with use when symptoms are present and discontinuation when symptoms disappear. In addition, patients with severe hepatic insufficiency need to use loratadine under medical supervision; and use with caution in pregnant and breastfeeding women, because antihistamines can reduce the positive rate of skin test, so it is prohibited for those who are allergic to the drug and used with caution in allergic patients.