Dermatovenerology Faculty – of foreign students Course – 4 Practical classes for distancial education

Latent syphilis is divided into: 
- Early latent syphilis (up to 2 years after infection); 
- Late latent syphilis (disease duration more than 2 years). 
Depending on the reaction of the body to the introduction of the causative 
agent of syphilis, the course of infection can be a classic staged or prolonged 
asymptomatic. 
 
PRIMARY PERIOD OF SYPHILIS (premaria) 
Syphilis infection conditions: 
1. sufficient amount of virulent Treponema palidum (2-3-5); 
2. damage to the skin and mucous membranes - the entrance gate. 
3. presence of contagious period. 
At the end of the incubation period, primary syphilema or chancre ( ulcus 
durum ) develops at the site of introduction of Treponema palidum. Localization of 
solid chancre characterizes the method of infection. During sexual infection, the 
hard chancre is located in the area of the external genitalia, however, it can be 
located on any part of the skin or visible mucous membranes. At the site of 
inoculation of Treponema palidum, first there is limited erythema, which quickly 
turns into a papule. Erosion or an ulcer appears on the surface of the skin. 

---

Ifepidermal cells are rejected, an erosive chancre is formed; if connective tissue is 
also rejected, ulcerative chancre is formed. 
Clinical characteristics of solid chancre 
- Defect up to 0.5-1 cm in diameter. 
- A round or oval shape, depending on the anatomical and physiological 
characteristics of the affected skin. For example, in the corners of the mouth and in 
the folds of the anus the shape of the chancre is oblong, and in the coronary groove 
of the penis and at the nipples of the breast it looks like a crescent moon. 
- Saucer-shaped edges. There are never undercut or sheer edges. This plays a 
certain diagnostic role. 
- The bottom is flat, shiny, as if varnished. The color of the solid chancre is red, 
often compared with the color of fresh meat in the section. Sometimes the chancre 
acquires a gray color, resembling a spoiled fat. 
- The basis of the solid chancre is compaction (induction) - cartilage compaction, 
which is a pathognomonic symptom. 
- The skin around the chancre is usually without signs of inflammation. 
- The solid chancre is painless! This is due to the fact that Treponema palidum 
secretes anesthetics that affect the Schwanian membranes of nerve endings. 

---

- With the usual development of erosive hard chancre, a pigmented spot remains, 
after an ulcerative - a star scar. 
Atypical chancres present great difficulties for the diagnosis of syphilis.