If children have red blisters on their lips, it is mainly due to the following conditions: 1. Lip infections caused by viral infections in children. If children have low immunity, such as fatigue or too much exercise, they often suffer from viral infections, and viral infections can cause lip infections in children. In this case, the child has red blisters on the lips and sometimes herpes inside the child’s mouth, and the child often has a low fever as well as anorexia and a relatively poor appetite. In this case, you can apply ganciclovir ointment to children for external application, or give children with the application of Pudilan anti-inflammatory oral solution and other treatment. 2, due to allergies, if children belong to allergic body, after eating fish, shrimp and other seafood will also appear red blisters on the lips, and very itchy. For this situation, children can be treated with loratadine.