The corners of a child’s mouth rot consider thrush, herpes stomatitis and other diseases caused. 1. Thrush: a disease in which Candida albicans infection forms a white film on the surface of the oral mucosa. Most common in newborns and infants, can appear in the corners of the mouth rotten performance. Can also be manifested in the oral mucosal surface covered with white milk clot dots or small flakes, can gradually merge into a large area, not easy to wipe away, no inflammatory reaction around, no pain, no salivation. 2. Herpetic stomatitis: a disease caused by herpes simplex virus type I infection. It often occurs in the buccal mucosa, gums, tongue, lips, lips red and neighboring perioral skin. At the onset of fever, single or clusters of small herpes appear in the above areas, surrounded by a red halo. Due to the severe pain, the child may show refusal to eat, salivation, irritability, often found by refusing to cry. There are many reasons for the rotting of the corners of a child’s mouth, such as vitamin B deficiency, etc. It is recommended that the family take the child to the hospital for a relevant examination and a clear diagnosis. The child should pay attention to local cleanliness and develop good hygiene habits. Diet to light, eat more fresh fruits and vegetables and lean meat.