SPIROCHETAL DISEASES Significant in the immunologic life of the host. For the physician it is important to realize that studies in this area are very few, that accepted treatment practices need not be reconsidered in early syphilis, and that in late syphilis special considerations continue to pertain. The early treponema and the resulting metastatic foci are reflected in the diversity of the body organs involved in the pathology of this chronic inflammation. The macroscopic characteristics of skin manifestations are described later.
The histopathology of lesions is basically characterized by endarteritis and peri-arthritis of the small vessels and capillaries, which show infiltration of lymphocytes and plasmatocytes and multiplication of histiocytes. Granu-lomatous inflammation is typical of the late stages of syphilis as of other chronic infections, e.g., tuberculosis. In the early skin lesions in which many treponemes are pr ent_ lymphocytosis and plasmacytosis are particularly marked, although varying in intensity.
Acanthosis usually occurs. Many treponemes are present Lymph nodes in the early disease show adenitis with prominent follicles, plasmacytosis, sometimes focal necrosis, fine fibro-sis, and presence of treponemes. The histologic picture in lesions and lymph nodes is compatible with antibody production by stimulated cells (WHO, 1970). Late nodular and gummatous lesions (usually treponeme-free) show chronic granulomatous tissue with lymphocytes, epithelioid cells, and eventually giant cells in addition to the endovascular changes of early lesions. Coagula-Cian necrosis occurs from obstruction endarteritis, possibly as a result of delayed hypersensitivity. In cardiovascular syphilis, there is endarteritis of the vasa vasorum, particularly in the ascending aorta and arch.
SPIROCHETAL DISEASES layers of the large vessel are involved with the destruction of elastic and muscle tissue, weakening the entire structure and pre-disposing to the aneurysm. The aortic ring may also be weakened with shortening and thickening of valve leaflets leading to regurgitation. Coronary Ostia may become narrowed, resulting in rare ischemic heart disease. Central nervous system syphilis is either meningovascular with inflammation of the pia-arachnoid and its vessels or parenchymatous with the nervous tissue attacked. The leptomeningitis may be acute or chronic. Infiltration of small meningeal vessels may cause thrombosis and local brain damage. The parenchymatous process may engender paresis if the brain is predominantly involved, or tabes dorsalis if the spinal cord is predominantly involved.
Tabes be-gins as extradural leptomeningitis around the dorsal nerve roots, followed by degeneration of axis cylinders and demyelination of posterior columns of the spinal cord. Optic atrophy may occur from basal meningitis or interstitial neuritis in the nerve or chiasma, or central gummatous Lesions may affect the optic nerve directly. Info-movement of afferent vessels to the spinal cord may lead to degeneration of pyramidal tracts and a rare condition known as Erb’s spastic paraplegia. Ophthalmic lesions include uveitis with serofi-fibrinous exudate and synechiae in acquired syphilis and interstitial keratitis with substantial lymphocytic infiltration in congenital syphilis. Rare membranous glomerulonephritis “Nehru-Other forms of visceral syphilis, e.g., interstitial nephritis, may occur.
In prenatal syphilis, the placenta is often voluminous, thickened, and pale with enlarged cotyledons and perivascular fibrosis throughout the villi, such as can also be seen in erythroblastosis (Rh-negative mother). The fibrous proliferation and monocellular infiltrates characterize fetal tissues in congenital syphilis; but in addition to the placenta changes, the most characteristic f i ndings are in the lungs (pneumonia alba) and the bones (osteochondritis and periostitis), the latter changes being diagnosable roentgen-logically.
SPIROCHETAL DISEASES Notwithstanding the diversity of the organs affected and the multiformity of the lesions under-lying the clinical picture, the elementary pathologic changes in all syphilitic processes are of vascular and inflammatory nature. Clinical Manifestations and Diagnosis. Untreated acquired syphilis shows a great variety of clinical manifestations, depending inter alia on the duration of the infection and the immunologic state of the host. The accepted classification of syphilis into early syphilis of fewer than four years’ duration and late syphilis of more than four years’ duration is based on these immunologic grounds, as well as on clinical and epidemiologic considerations rather than on definite “stages” of disease that may sometimes merge or overlap.
In congenital syphilis, in which there is the prenatal hematoge-nous transmission of T. pallidum to the fetus from the syphilitic mother, the disease is usually divided into early congenital syphilis in children less than two years old and late congenital syphilis in those who are older. Early Syphilis. The incubation period, initial lesions, secondary manifestations, and early latent period are comprised by this designation. The Initial Lesion (Primary Chancre). Following incubation of two to six weeks after the original infection, the initial lesion appears at the site of -implantation of T. pallidum: in males usually on the penile shaft, coronal sulcus, glans. or prepuce, and occasionally intraurethral: and in females on the external genitalia and cervix. In 5 to 10 per cent of patients, the initial lesions ax extragenital (lips, tonsils, fingers, within the anus, but also anywhere else).