Skinning and white flakes at the corners of the mouth can be considered as keratitis, lipitis, eczema and other diseases. 1. Keratitis: In addition to the above symptoms, if the patient has chapped and cracked corners of the mouth with inflammation, redness, swelling and pain at the corners of the mouth, keratitis can be considered. According to the different types of keratitis, the specific causes also vary. Infectious keratitis is mostly caused by fungal, bacterial, viral and other pathogens, the most common of which are Candida albicans, Staphylococcus aureus, Streptococcus, herpes viruses and so on. Traumatic keratitis is mostly caused by medical trauma such as the use of rough mouth mirrors, prolonged pulling of the corners of the mouth, inadvertent collisions, and excessive rubbing of tissues. Contact keratitis is triggered by exposure of the lips of allergic patients to allergens (lipstick, face cream, lipstick, etc.). The main causes of malnutrition keratitis are vitamin deficiency (especially vitamin B), insufficient supply of iron, protein and other nutrients. 2. Lipitis: In addition to the above symptoms, if the patient also has symptoms of recurrent dryness, flaking, itching and oozing on the lips, then it can be considered as lipitis; the main causes of this disease include sunlight exposure, climate change, local irritation, and contact with allergens (e.g., cosmetics, medications, etc.). 3. Eczema: patients with chronic eczema will also have scaly skin in the recovery period; this disease is mostly related to abnormal immune function, systemic diseases (endocrine diseases, nutritional disorders, etc.), contact with allergens, long-term nervousness, and so on. It is recommended that patients undergo relevant examinations in a timely manner to clarify the cause of the disease and receive appropriate treatment under the guidance of the doctor.