Various secondary phenomena now oc cur in the different tissues: General en largement of the lymphatic glands,— general adenopathy,—as a result of (1) the proliferation of the cells carried to them by the blood, (2) the proliferation of their own lymphoid and connective tissue elements under the stimulus of the infection brought by the syphilized cells, and (3) an accumulation of in fected germinal material collected by the absorbents from the superficies of the body. Engorgement of the fauces and pharynx follows, due to a localized cell proliferation and accumulation in their rich net-work of lymphatics. Mucous patches are likely to occur, and are sim ply quasipapules upon moist mucous sur faces, due to a circumscribed collection of the characteristic cells,—constituting syphilitic granuloma in whatever lesion it may be found. The same description will apply to the true papule upon the integumentary surfaces. This papule may have an excessive accumulation of cells and become a tubercle, or, from pressure upon and interference with, the nutrition of the normal tissue-elements by the cells in combination with their own tendency to retrograde metamor phosis,—with or without complicating pus-infection,—a pustule, perhaps, forms that may break and result in ulceration. Nodes or peculiar periosteal swellings occurring in syphilis are collections of proliferating syphilitic cells—granulo mata.
The foregoing are the essential points in the pathology of active syphilis, as expounded by Otis, modernized by the addition of the microbial view of the disease. Whether the changes following the initial lesion are due to the trans ference to the system at large of an in fected cell, or to the action of a microbe similarly carried, the pathology of the disease as above set forth seems to be logical. There are many phenomena in the course of syphilis to which the syph ilized cell bears no particular relation.
Such phenomena were dwelt upon with especial emphasis by the opponents of the syphilitic pathology involved in the foregoing, when originally formulated by Otis. An acceptance of the microbial origin of the disease, however, at once harmonizes the apparent inconsistencies in the theory appearing from time to time in the natural history of syphilis, and seems to answer the arguments of the opponents of the theory so far as this particular phase of their opposition is concerned. Such phenomena as are in explicable upon the ground of localized cell-accumulation and tissue-obstruction are at once rationally explained by the action of syphilitic toxins elaborated by the specific micro-organism of the dis ease. The syphilized cell may reason ably be regarded as a carrier of, or as a collaborator with, the specific bacillus of syphilis in the production of toxins.
The danger of permanent injury to the tissues is proportionate to the amount of accumulated cells and the duration of their contact with the normal tissues, with consequent production of secondary changes. A careful study of syphilitic
lesions demonstrates the truth of this ' proposition, whatever theory of the pa thology of the disease is accepted. The proposition advanced by Otis in explana tion of the foregoing is hardly open to dispute. "The natural course of the syphilitic cell is to accumulate in and obstruct various tissues, thereby forming neoplastic masses similar in structure to inflammatory neoplasia, and finally to undergo retrograde metamorphosis and elimination, resulting eventually in spon taneous cure of the disease." As to the tissue-changes at the site of inoculation, the first manifestation of the disease is a peculiar lesion characterized by induration. This lesion is due to a localized accumulation of cells infiltrated in the meshes of the connective tissue and tunica adventitia of the blood-vessels, forming a circumscribed mass. The cells vary somewhat in character, those in the vascular walls being either round, spindle-shaped, or branched; but the bulk of the mass consists of the charac teristic round, multinuclear, granular cell. It is obvious that the mass is com posed of histological elements derived from transformation of the leucocyte or its derivatives. The changes are similar to those of simple dermatitis, save in the absence of exudate, the induration being dry and hard. The absence of fluid is probably dependent on thickening of the walls and contraction of the lumen of the blood-vessels, which render it dif ficult for serum to exude from them. This would also explain the relative anaemia and diminished nutrition of the neoplasm. There is also to be taken into consideration a quality of the syphilitic infection too infrequently considered: i.e., the fact that it has absolutely no irritating properties per se.
The peculiar affinity of the syphilitic process for the lymphatic tissues in gen eral is evidenced throughout the entire course of syphilis. There is a very in timate relation between the small blood vessels throughout the body and the beginnings of the lymphatic system. The small blood-vessels are surrounded by perivascular lymph-spaces. It has been claimed that the tunica adventitia of the smaller vessels is really a part of the lymphatic system. This arrange ment is to be taken into contemplation in considering the well-known facility with which infections of various kinds are taken up by the constant current existing between the blood-vessels and lymphatics via the tissues and conveyed to the general circulation. It also ex plains general lymphatic involvement in infections that primarily enter the gen eral circulation.