Small blisters around the child’s mouth may be caused by herpes simplex virus on the lips. Usually it is caused by poor body resistance, or mental stress, lack of sleep, partial food leading to malnutrition and immunity decline, so the child needs to go to the hospital in time if there are uncomfortable symptoms. It is generally recommended to use antiviral drugs, such as Four Seasons Antiviral Oral Liquid, acyclovir ointment, viral azole granules and other drugs. It is also recommended to supplement vitamin C, vitamin E.