Lupus erythematosus is a general term for the skin and mucous membrane lesions of SLE. More than 80% of lupus patients can develop skin and mucous membrane lesions, which are generally seen on the skin and mucous membranes throughout the body. Among them, facial pteroidal erythema is the most characteristic and common skin mucosal lesion in SLE. The butterfly erythema is usually located on the bridge of the nose and the cheeks of both cheekbones, and is symmetrically distributed, so named because it resembles a pair of wings of a butterfly. When the disease is active, butterfly erythema is more obvious, and after treatment, the color of the erythema turns lighter, the area is reduced, and even fades away gradually. In addition, the skin and mucous membrane lesions of SLE include photosensitivity, peripalpebral erythema, discoid erythema, erythema nodosum, lipofuscinosis, reticular cyanosis, Raynaud’s phenomenon, oral or nasal mucosal ulcers, etc. They can be found on the face, limbs, fingers, toes, chest, abdomen, back, oral and nasal cavities, etc. Since skin mucosal lesions have a high incidence in SLE and most of them have skin mucosal lesions as the first manifestation, women of childbearing age, especially those with a family history of lupus, should consult a doctor promptly once they develop skin mucosal lesions that are difficult to be explained by conventional diseases to investigate the possibility of lupus.