Dry weather in winter or when living in an air-conditioned room is prone to dry and cracked corners of the mouth, i.e. corns of the mouth, usually initially dry lips, followed by erythema, edema, oozing, nodules at the corners of the mouth, some people think it is “fire”, in fact, in medicine is called “corns of the mouth”, turning into In chronic cases, the local mucous membrane skin is moist, cracked, rough and flaky with radioactive wrinkles from the corners of the mouth outward. Most of the corns of the mouth are chapped and cracked due to dry weather, and vitamin B deficiency can also occur due to reduced dietary intake of vitamins. Usually, the main focus is on prevention, applying lip balm in cold and dry weather to prevent dry and cracked corners of the mouth. If the symptoms of keratoconjunctivitis have appeared, you should keep the corners of your mouth dry, do not be soaked in saliva, and avoid opening your mouth wide; while applying moisturizer, apply ointment containing antibiotics if more serious symptoms such as infection and pus occur; in addition, pay attention to a balanced diet, eat more fresh green vegetables, etc., and take vitamin B2 orally if necessary; remember not to lick the corners of your mouth with your tongue, as the amylase and lysozyme contained in saliva in The residue in the corners of the mouth can easily destroy the outer protective film of the mouth and lips, while forming a hypertonic environment, leading to more and more local dryness and thus erosion. In addition, it is necessary to pay attention to the rest of the corns of the mouth, stay up late, cold, mental stress, etc. will make the body resistance to decline, the corners of the mouth ulcer is not easy to heal.