Children with blisters inside the lips fever is common in herpes pharyngitis, chickenpox, hand, foot and mouth disease and other diseases, should be taken according to the specific cause of the general treatment, medication and so on. 1. Herpetic pharyngitis: often with high fever, gray-white herpes can be seen in the oral mucosa. Mainly symptomatic treatment, keep the mouth clean, available salt water gargle, can also be used to reduce the pain of pharyngeal tablets. For fever to physical cooling-based, high fever can be given to acetaminophen and other drugs to reduce heat treatment, usually should also pay attention to more rest, drink more water, room ventilation. 2. Chickenpox: it is caused by chickenpox virus, it is a self-limiting disease, symptomatic treatment. Children should be isolated in time, can be given appropriate antipyretic and keep clean in the mouth, to prevent children from scratching with their hands. If necessary, antiviral drugs such as acyclovir can also be used. The prognosis is generally good. 3. Hand, foot and mouth disease: there may be scattered herpes on the feet, mouth, buttocks, should pay attention to isolation to avoid cross-infection, and appropriate rest, light diet, good oral cleaning. Seriously ill children should be closely monitored, control neurological symptoms, keep the airway open. Children with blisters inside the lips fever, there may be other reasons, need to go to the hospital as soon as possible, by the doctor according to the condition of the individualized treatment plan, so as not to delay the condition.