Stomatitis (angularcheilitis) is an acute or chronic inflammation of the skin and adjacent mucous membranes in the area of the corners of the mouth caused by different factors. It is prevalent mainly among children and is associated with septicococcal or Candida albicans infections or vitamin B2 and vitamin P deficiency. Accompanying symptoms include dryness of the mouth and lips, oozing from the mouth and lips, and radioactive wrinkles in the corners of the mouth outward. Etiology: 1, mechanical factors: inappropriate tooth position, resulting in the upper lip overlapping the lower lip, the corner of the mouth wrinkles, the mucosa there is often in the impregnation. 2, nutritional deficiencies: riboflavin deficiency, which can be accompanied by strawberry-like tongue and scrotal itching, etc. Excessive labor, excessive physical exertion or physical weakness, malnutrition, iron, protein supply deficiency and multivitamin deficiency: such as niacin, vitamin B6, etc. can cause the disease. 3, infection: the pathogenic bacteria are mostly low virulence septicococcus or Candida albicans, mostly seen in children. Certain skin diseases, such as: atopic dermatitis, seborrheic dermatitis abnormal combined with orofacial dermatitis. Salivary disease infiltrating the corners of the mouth can cause this disease; biting fingers, biting pen sticks, etc. can also cause this disease. Diagnosis: 1. Initially, dry lips, erythema, edema, oozing and crusting at the corners of the mouth. When it becomes chronic, the local mucous membrane skin is moist, cracked, rough and flaky, and the radioactive wrinkles occur outward from the corners of the mouth. 2, caused by malnutrition, anemia, riboflavin deficiency can be accompanied by oral, tongue and pubic mucosal damage, such as glossy tongue, scrotal skin redness and corresponding systemic symptoms. 3, more symmetrical on both sides, but also unilateral onset. Conscious burning sensation. 4.In malnourished children, pustules may appear in and around the corners of the mouth, mostly related to septicococcal infection.