Children’s lips are swollen and transparent at night, angioedema may be caused by allergy, infection, trauma, mosquito bites and so on. 1. Allergy: Eating allergenic food or lips in contact with allergens can cause angioedema of the lips, which may be accompanied by itching, redness and other symptoms. 2. Infection: dental caries caused by periapical inflammation, infection with herpes simplex virus, labiitis, etc., can appear the symptoms of lip swelling. 3. Mosquito bites: After the lips are bitten by mosquitoes, the local inflammatory reaction can also lead to lip swelling. Children’s lips are swollen and transparent at night, different causes of different treatments, need to actively go to the hospital, clear cause and then do treatment.