Syphilis that is less than two years old is called early syphilis, and syphilis that is more than two years old is called late syphilis (stage III syphilis). Stage III syphilis can occur in patients with untreated syphilis. At this time, syphilis spirochetes can invade the skin, soft tissues, bones, cartilage, testes and other non-fatal tissues and organs, but also the heart, brain, blood vessels, nervous system and other internal organs, causing serious consequences. The characteristics of late syphilis rash occurring on the skin and mucous membranes are: 1. dendritic infiltration; 2. small number and asymmetric distribution; 3. mild inflammatory phenomena and subjective symptoms; 4. ulcers can be formed, with a tendency to heal in the center and spread around the ulcer, which can be circular, multi-ring, or horseshoe-shaped; 5. large destructive, scar formation after healing, and pigmentation at the edges; 6. faster healing with anti-syphilis treatment. Common types include nodular syphilis rash, dendritic swelling and proximal joint nodules. Late stage bone syphilis is common with osteochondritis, often invading long bones, but with less damage, less pain and a slower course. Advanced osteosyphilis can also occur as dendritic osteitis of bone, commonly in flat bones (e.g., skull), and can result in dead bone and skin ulcers. Advanced syphilis in the eye can result in iridocyclitis, retinitis, and keratitis, which can lead to blindness. Advanced cardiovascular syphilis occurs 10-30 years after infection and can lead to aortitis, aortic valve insufficiency, aortic aneurysm, coronary artery stenosis, and myocardial dendritis. Advanced neurosyphilis can result in meningeal dendritis, cerebrovascular syphilis, cremasteric syphilis, and paralytic dementia due to cerebral parenchymal syphilis. In addition, whistling, digestive and urinary syphilis can also occur. In conclusion, syphilis can affect almost all organs of the body, and a variety of complex signs and symptoms can occur as the disease progresses. Therefore, once you find out you have syphilis, don’t be afraid to seek medical attention, you should go to a regular hospital dermatology department in a timely manner. In order to avoid delaying the disease, resulting in irreparable consequences. The picture shows a gum swelling in the skin of stage III syphilis