Sudden rash on face may be caused by eczema, folliculitis, contact dermatitis and other diseases, which can be improved by general treatment and medication. 1. Eczema: Eczema may cause sudden rash on the face, patients should keep the local clean, avoid excessive cleaning, scratching the affected area. Topical glucocorticoid drugs can be used as prescribed by the doctor to play the role of anti-inflammatory and anti-allergic, common drugs are hydrocortisone, halometasone and so on. Oral desensitization drugs can be taken in severe cases. 2. Folliculitis: sudden rash on the face may also be caused by folliculitis, patients should avoid close contact with others to avoid infection. Facial folliculitis is usually mainly bacterial infection, you can follow the doctor’s instructions for topical antibiotic drugs, such as erythromycin, clindamycin and so on. 3. Contact dermatitis: If contact dermatitis causes a sudden rash on the face, the patient should avoid re-exposure to irritants. You can follow the doctor’s instructions to use topical glucocorticosteroids, such as trimethoprim and mometasone furoate. In severe cases, oral desensitizing drugs can be taken. Sudden rash on the face has more causes, it is recommended to go to the hospital, with the doctor standardized treatment.