The common causes of repeated flakiness at the corners of the mouth are divided into the following cases: 1, the corners of the mouth always flakiness is a manifestation of stomatitis, the most common reason that lack of B vitamins; 2, bad habits, often licking the lips, licking the corners of the mouth or drooling, because children will be drooling in bed at night, dripping drool will impregnate the skin here; 3, weaker patients, such as the elderly or children, when infected with Candida can suffer 4, allergies, often try lipstick or eat spicy, stimulating things, if the skin is broken, it will form allergies, repeated contact, will lead to the phenomenon of corneal erosion; 5, unilateral corner of the mouth when blistering, herpes simplex is more likely, if repeatedly grow in the same place, the patient should be alert to herpes simplex infection.