Children with rotten corners of the mouth may be physiological factors, but also may be the manifestation of certain diseases, such as stomatitis, lack of trace elements, etc., should be timely consultation to find out the cause of the disease. 1. Physiological factors: if children like to bite their lips, sucking fingers, resulting in drooling, it may cause the corners of the mouth rotten. 2. Pathologic factors: (1) keratitis: children with low immunity do not pay attention to oral hygiene, there may be bacterial and viral infections, and there will be ulceration of the skin at the corners of the mouth, causing increased secretion or pain. (2) lack of micronutrients: children in the growth and development of the period of high nutritional needs, in the lack of micronutrients may occur after the immune system is low, but also the corners of the mouth ulcers. If you find that the corners of your child’s mouth are rotting, it is recommended that parents should consult a doctor in a timely manner to clarify the cause of the disease and give targeted treatment.