Redness on both sides of the face may be related to solar dermatitis, rosacea, lupus erythematosus and so on. 1. Solar dermatitis: If the sides of the face are red after sun exposure, it may be acute sunburn caused by sunlight, and the patient will experience symptoms such as itching and flushing. 2. Rosacea: may have this disease itself, when affected by environmental temperature changes, due to the expansion of capillaries will also appear on the cheeks of the red phenomenon. 3. Lupus erythematosus: It is caused by autoimmune abnormalities and other causes of skin damage, lesions manifested as butterfly-shaped erythema on the cheeks, and generally can also involve the neck, forehead and other parts. Redness on both sides of the face can also be seen in other causes, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions to carry out relevant examinations, with the help of the doctor to clarify the causes, and targeted treatment or treatment.