Children’s mouth redness may be physiological factors, bad habits, allergies and other factors. 1. Physiological factors: children drink too little water every day, and the weather is also relatively dry, will lead to a circle of the mouth red, there are no other clinical symptoms, you should drink more water, and improve the indoor temperature and humidity, can be improved on their own, do not need to carry out other treatments. 2. Bad habits: children have the bad habit of licking lips, long-term use of the tongue to lick the lips, will lead to a circle of the mouth red, serious cases can also lead to infection, inflammation. 3. Allergy: such as consuming some allergic food, resulting in an allergic reaction to the lips, will make the lips red, may also be accompanied by burning sensation, itching and other symptoms. Children with redness in a circle of the mouth, there are other abnormalities, parents are advised to take their children to the doctor for examination and treatment.