Possible causes of red marks on the face include congenital nevus, rosacea, systemic lupus erythematosus, etc., which can be helped to subside by photodynamic therapy and medication. 1. Congenital nevus: If the red marks on the face exist since birth, they may be caused by congenital nevus such as nevus of bright red spot, strawberry hemangioma, etc. Such patients need to be treated with laser therapy, photodynamic therapy and other photoelectric treatments to help subside the red marks, and they often need multiple treatments to have better results. 2. Rosacea: If the red marks mainly occur in the middle of the face, and accompanied by capillary dilatation, rosacea, cheek pinpoint to green bean size pimples and other symptoms, may be suffering from rosacea, such as topical fusidic acid cream, tacrolimus ointment and other ointments applied locally, and oral doxycycline, minocycline and other drugs for serious cases, effective treatment of rosacea. 3. Systemic lupus erythematosus: If the red marks are in the form of butterfly-shaped erythema on the face, accompanied by joint swelling and pain, internal organs and multiple systemic damage and other related symptoms, it may be suffering from systemic lupus erythematosus, such patients can be taken orally through the glucocorticosteroids, immunosuppressants (cyclophosphamide, azathioprine, etc.) and other drugs to help regulate the immune system, which can help to subside the face of the red marks. It should be noted that, when abnormal erythema occurs on the face, it is necessary to go to a regular medical institution in a timely manner, after clarifying the cause of the disease, under the guidance of a physician to carry out systematic treatment, to avoid the occurrence of adverse reactions.