The basic lesions of syphilis are: (1) endovasculitis, with swelling and hyperplasia of endothelial cells; (2) perivasculitis, with massive lymphocytic and plasma cell infiltration. In addition to the above changes, there are also epithelioid cells and giant cell granulomatous infiltration, sometimes with necrosis. I. Sclerosing chancre: A perivascular infiltrative lesion is seen, mainly with lymphocytes, including CD8+ and CD4+ cells, plasma cells and histiocytes, accompanied by proliferation of capillary endothelium and subsequent occlusion of small vessels. In addition, syphilis spirochetes are seen in the interstitial epithelial cells in the chancre, in the capillaries, and in the perilymphatic vessels and local lymph nodes. The first of these is the syphilis papule, which is characterized by hyperkeratosis of the epidermis, invasion of neutrophilic polymorphonuclear leukocytes into the dermal papillae, and infiltration of monocytes, plasma cells and lymphocytes around the deep dermal vessels. There are obvious plasma cell infiltration around the blood vessels, cuff-like arrangement, capillary hyperplasia, with epidermal cells inside and outside edema. The syphilis spirochetes were found in about 1/3 of the cases of flat warts by silver staining, mainly located within the epidermis and a few around the superficial vessels. The main reason for this is that it is not a good idea to have a good idea of the size of the skin. Fifth, the difference between nodular syphilis rash and dendritic swelling is the extensiveness and location of the lesion. Nodular syphilis rash granuloma is limited to the dermis, caseous necrosis is slight or absent, and large blood vessels are not involved; dendritic swelling has extensive lesions that can involve the subcutis, caseous necrosis is obvious, and large blood vessels are often involved.