Syphilis Symptoms And Clinical Stages
Syphilis, caused by the spirochaete Treponema pallidum is one of the most important venereal disease. It is a worldwide disease, which is transmitted almost exclusively by sexual contact (acquired syphilis). The infection is also spread from an infected mother to her fetus (congenital syphilis). Blood transfusions, direct inoculation and nonsexual contact are only rare causes of syphilis. The course of acquired syphilis is classically divided into 3 stages: primary, secondary, and tertiary syphilis.
Primary syphilis. The classic lesion of primary syphilis is the chancre, a characteristic ulcer located at the site of Treponema pallidum inoculation. The chancre appears usually on the external genitals (gland penis, vulva), one week to 3 months after exposure, with an average incubation period of 3 weeks. In approximately 10% of cases the chancre may be extra-genital: lips, fingers, oropharynx, anus, rectum, or some other site. In about 50% of females and 30% of males, primary lesions either never develop, or are not detected.
The chancre begins as a solitary, slowly growing, hard, pale brownish – red, usually painless nodule, that varies in size up to several centimeters in diameter. Then it superficially erodes to create a clean-based, shallow ulceration on the surface of the slightly elevated papule.
The contagious induration characteristically creates a button like mass directly subjacent to the eroded skin or mucosa, providing the basis of the designation hard chancre. When the lesion is on a mucous surface and the part is not kept clean, there may be more extensive ulceration and suppurative exudation.
The ulcer persists for 3-12 weeks, during which the inguinal lymph nodes, usually on both sides, become somewhat enlarged and hard, with nonspecific acute or chronic lymphadenitis (inguinal lymphadenopathy). The chancre heals without scaring.
Histologically, the chancre is characterized by a intense mononuclear leukocytic infiltration, chiefly of plasma cells with scattered, macrophages and lymphocytes, which are mainly responsible for the hardness and swelling. Obliterative endarteritis is present within this inflammatory reaction.
Secondary syphilis. The most common presentation of secondary syphilis is a rash, which appears 2 weeks to 6 months after the chancre heals, with multiple symmetrical lesions of the skin and squamous mucous membranes. The rash is erythematous (discrete red-brown lesions) and maculopapular, involving the trunk and extremities and often including the palms and soles. Reddened mucous matches may appear in the mouth or vagina; they are called mucous patches and are teem with bacteria, being highly infectious.
Papular lesions in the region of the penis or vulva may become large, elevated, broad plaques. These flat red-brown elevations (up to 2-3 cm in diameter) are designated conylomata lata (wart like lesions on the genitals). The overlying epithelium is intact and hyperplastic.
General slight enlargement of lymph nodes is also common. Characteristic changes include a thickened capsule, follicular hyperplasia, increased numbers of plasma cells and macrophages, luetic vasculitis.
The secondary lesions are usually accompanied by fever, anemia and general malaise. After some months all these features disappear spontaneously and the disease becomes latent.
Histologically, in the secondary lesions in the skin and mucous membranes, the main changes are vascular enlargement and infiltration, mainly of plasma cells, but also lymphocytes, and macrophages. When the rash is distinctly papular it is usually accompanied by thickening of the epithelium.
Tertiary syphilis. After the lesions of secondary syphilis have subsided, an asymptomatic period lasts for years or decades. However, during this latent period, spirochetes continue to multiply, and the deep-seated lesions of tertiary syphilis gradually develop and expand. Only a third of untreated patients with syphilis develop tertiary lesions.
Tertiary lesions appear irregularly, especially in the internal organs, skin and mucous membranes; they are few but usually much larger than the primary and secondary lesions, and lead to serious and permanent damage.
Gumma is a characteristic lesions of tertiary syphilis, which may form in any organ or tissue. It is a granulomatous lesion composed of a central area of coagulative necrosis, epithelioid histiocytes, occasional giant cells and peripheral fibrous tissue. Gummas are most commonly found in the skin, bone and joints, although the lesion may occur in any body site. They cause extensive destruction like in the nasal bones with loss of the bridge of the nose and perforation of the palate, ulceration and destruction of the larynx, creeping ulcers in the skin.
Of special importance are the cardiovascular lesions. Cardiovascular syphilis principally involving the aorta, may become manifest after several years from the initial infection. It causes inflammatory scarring of the tunica media (mesaortitis) with weakening and dilatation (aneurysm formation) and narrowing the corronary ostia (may cause myocardial infarction).
Neruosyphilis is another late manifestation. The slowly progressive infection damages the meninges, cerebral cortex, spinal cord, cranial nerves, or eyes. Tertiary syphilis involving the central nervous system is sub-classified according to predominant tissue affected. Thus, there are references to meningovascular syphilis (meninges), tabes dorsalis (spinal cord), and general paresis (cerebral cortex).