There are many reasons why the edge of the lips itch, common lipitis, contact dermatitis, angioedema and so on. 1. Lipitis: local chronic irritation, as well as allergic factors, physical stimuli can cause an inflammatory reaction of the lips, potentially leading to itchy lip edges. 2. Contact dermatitis: contact with certain allergens may cause allergic reactions, causing itchy lips, accompanied by redness and swelling of the skin, erythema, oozing and other changes in appearance. 3. Angioedema: related to drugs, food, dust, inhalants and other induced allergies, can cause limited edema of the lip area, accompanied by mild itching symptoms. Itchy lips edge, there may be other reasons, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for treatment.