Lip round or oval erythematous mucosal lesions preferably occur on the lower lip lip red, round or oval erythematous, slightly depressed in the center, slightly elevated with dark red edges, and white radiating patterns around the lesion. The lip lesions often go beyond the lip red edge and involve the skin, blurring the mucosal skin boundary. There is hyperpigmentation or hypopigmentation around the lesion area. The skin lesions are usually found on the head and face and are characterized by scaling, dilated capillaries, follicular keratin plugs, hyperpigmentation and/or hypopigmentation, and scar formation. The typical manifestation is “butterfly spots” around the nose. Laboratory tests show accelerated sedimentation, increased globulin, positive rheumatoid factor, and positive antinuclear antibodies. There is an increased ratio of helper T cells (CD4)/suppressor T cells (CD8), and tissue biopsy is of great importance. The time to take the lesion group tissue should be chosen about 2 weeks after the healing of the erosion is more appropriate. Immunofluorescence examination is important for diagnosis and differential diagnosis. Discoid lupus erythematosus should be differentiated from the following diseases: 1. Chronic labyrinthitis: Chronic labyrinthitis, especially chronic erosive labyrinthitis, also occurs on the lower lip and is easily confused with discoid lupus erythematosus on the red part of the lip. DLE has skin lesions on the head, face, upper extremities, chest, and neck, with erythema, follicular keratin plugs, scaling, hyperpigmentation or depigmentation, capillary dilatation, and atrophy, whereas labyrinthitis has no skin lesions DLE pathology is characterized by atrophy of the sphenoid layer, liquefied degeneration of the basal layer, and infiltration of inflammatory cells in the deeper layers and around the blood The pathology of DLE is characterized by atrophy of the spinous layer, liquefaction and degeneration of the basal layer, and infiltration of inflammatory cells in the deep layer and around the blood. Immunofluorescence examination of DLE has fluorescent bands in the basal layer. 2, lichen planus: OLP skin lesions are symmetrical, occurring on the extremities or trunk, as light purple polygonal flat papules with dilated follicular pores, covered with scales, and sometimes with keratinous plugs on the ground of scales. In the oral mucosa lesions are round or oval, with a central shrinkage and thinning, surrounded by a white radiating pattern, and the red lip lesions often exceed the red lip margin. Pathological examination is important for differentiation. Pathological changes: discoid lupus erythematosus. Flat moss spiny cell laminae thinning, spiny layer atrophy more significant Spiny layer can be atrophied, predominantly hyperplastic Inflammatory cell distribution. Scattered infiltration Lymphocyte infiltration zone Collagen fibers Degeneration, disintegration and fracture Submucosa, inflammatory cell infiltration around blood vessels – Less inflammatory cell infiltration around blood vessels. 3. Benign lymphoproliferative labyrinthitis: a limited lesion that occurs on the Bian lip, with the typical symptom of paroxysmal intense pruritus. The histopathological manifestation is lymphocytic infiltration in the lamina propria of the mucosa and the formation of lymphoid follicle-like structures.