Herpes on the baby’s mouth and tongue may be caused by herpetic stomatitis, hand, foot and mouth disease and so on. 1. Herpetic stomatitis: it is caused by viral infection, which can be manifested as herpes on the surface of the tongue, oral mucosa and pharyngeal isthmus. Babies will salivate (drool) and refuse to eat due to oral pain. 2. Hand, foot and mouth disease: caused by enterovirus infection, in addition to the manifestation of the tongue, oral mucosa, pharyngeal isthmus herpes, hands and feet, buttocks can also be seen rash, may also be accompanied by fever. Herpes on the baby’s mouth and tongue may also be caused by inadvertent dental collision bite, or lack of vitamins and other causes, should be under the guidance of a doctor to clarify the cause of the disease, standardized treatment.