Sudden redness and swelling of the face may usually be caused by acute urticaria, contact dermatitis, salpingitis and other diseases. 1. Acute urticaria: the cause of the disease is complex and can be divided into exogenous (such as drugs, food, physical factors, etc.) and endogenous (such as mental factors, immune abnormalities, etc.). The onset of this disease is acute, patients can suddenly feel the face or other parts of the skin itching, and the itchy parts will soon appear red or pale white masses, accompanied by edema. 2. Contact dermatitis: contact dermatitis patients with facial skin in contact with insect hair, plant pollen or chemicals (such as hair dye, etc.), easy to trigger the disease, resulting in patients with facial skin erythema, edema, and can be accompanied by pimples, blisters. 3. Danovirus: mostly caused by type B hemolytic streptococcus infection, pre-morbidity, the patient may have fever and other symptoms, the patient’s face, calves, feet, back and other parts of the progressive expansion of erythema, and will be accompanied by swelling, burning sensation. In addition, there are many other causes of sudden redness and swelling of the face, it is recommended that patients go to the hospital in time to find out the cause of the disease, and then receive treatment as soon as possible.