1, angioneurotic edema, that is, allergic state, is a temporary, localized and painless subcutaneous or submucosal edema, which is mainly caused by type I allergic reaction caused by a protein and drugs. The swelling develops rapidly, and it is obvious in about ten minutes. The edema stage is bright, flush, painless and edema, and the swelling can subside within a few hours or one to two days. Edema is most common in the upper lip, characterized by hypertrophy and warping of the upper lip, which is limited to the alar area of the upper lip.

2. Odontogenic oral and maxillofacial space infection. Because the apical inflammation has not been treated and treated in time, the abscess and inflammation in the apical part of teeth spread further, leading to oral and maxillofacial space infection.

3. Do not rule out the possibility of mosquito bites. In this case, we should go to stomatology and dermatology in time to make a clear diagnosis and treatment.