Erythema on the face without pain or itching may be caused by diseases such as cutaneous lupus erythematosus, erythema multiforme, and trichotillomania. 1. Cutaneous lupus erythematosus: the cause may be related to genetic factors, environmental factors, infections and other reasons. Patients will have edematous erythema on the cheeks and nose, which is bright red or deep red, and usually without itching or pain. 2. Erythema multiforme: It is an acute immune-mediated disease. Localized target-shaped lesions are the hallmark of the disease, and erythema, papules, blisters and other symptoms will also appear, often symmetrically distributed on the extensor side of the extremities, and then spread centripetally, most commonly found on the face, distal limbs and other parts of the face, and often do not have pain, itching. 3. Capillary dilatation: the cause of the disease is not clear, may be related to genetic, environmental, physical and other factors. It is mainly manifested as erythema of the skin, mostly seen on the face, and patients usually do not have self-conscious symptoms. Erythema on the face is painless and itchy for more reasons, it is recommended to go to the regular hospital for consultation and examination, and to clarify the cause of the disease after symptomatic treatment.