SYPHILITIC DISEASE OF THE LUNG.
BY EDWARD T. BRUEN, M.D.
DEFINITION.—Lesions of the lungs with a syphilitic impress include catarrhal inflammation of the bronchial mucous membranes, chronic inflammatory new formations, which affect especially the connective tissue, producing sclerosis or else gummatous growths.
HISTORY.—From the early part of the eighteenth century attempts have been made to create a word-portraiture representing the peculiar features of syphilitic pulmonary disease as a separate entity. It has been defined histologically and clinically from simple and from fibroid phthisis, or from cases of syphilis in which a damaged state of the general health has fostered the development of phthisis. But the question, Is there a peculiar microscopic and macroscopic anatomy, or a special symptomatology by the aid of which the cause, seat, and dissemination of pulmonary syphilis can be recognized? remains even now but partially removed from the field of debate and conjecture, although unquestionably the syphilitic poison bears intimate relation with various pulmonary processes.
ETIOLOGY.—Predisposing and Exciting Causes.—Syphilis of the lungs is a rare disease as compared with the forms of specific laryngitis, but even here Leman asserts that there is an early simple catarrh of the larynx indistinguishable from the specific catarrhs. Whistler, in recording his observations upon 88 cases of the lesions found in syphilis of the larynx, observes that catarrhal congestions in early laryngeal syphilis simulate the same lesions from ordinary causes. Schnitzler lays particular stress on the association of pulmonary syphilis with affections of the larynx and a specific bronchitis which may occur in the first two months after inoculation. Many other writers on this subject assert that laryngeal and bronchial catarrh attend the period of early skin eruptions, disappearing in consequence of an antisyphilitic treatment.
The rarity of pulmonary syphilis has been further attested by the observations of Greenfield, who states that out of 22 cases of visceral syphilis, only 1 occurred in the lung and 4 in the larynx and trachea: in these cases, while the dura mater and cerebral vessels were extensively diseased, no trace of skin affection could be found. Goodhart has collected from the post-mortem records in Guy's Hospital during twenty-two years 189 cases of visceral syphilis, but in only 38 of these chronic lung disease occurred. Phthisis associated with syphilis is usually a late secondary or tertiary process, which appears from two to five years after the infection; in rare cases ten—even twenty—years have been said to elapse before the supervention of pulmonary trouble. Cases of phthisis associated with syphilis have, however, been described as occurring within the first twelve months after infection. Further investigation may establish these cases of early pulmonary syphilis as attributable to violent systemic infection, or their etiology may be involved in the deterioration of the general health which sometimes occurs. Moreover, one must remember that simple phthisis may more readily be developed in the scrofulous syphilitic, owing to the predisposition of such persons to catarrhal forms of inflammation. In the progress of syphilis there is also a tendency to catarrhal processes through anæmia and damaged general health, which may predispose certain cases to an ordinary type of phthisis. The origin of the new formation in both tubercular and syphilitic phthisis is similar—viz. the arterial, lymphatic, and the peribronchial sheaths, spreading thence to the interlobular connective tissues. It is therefore not surprising that it has been difficult to differentiate the tubercular from the specific forms of phthisis, and Goodhart asserts that there is no histological difference between syphilitic and tubercular phthisis, except that the former is more vascular.
We may assume that true pulmonary tuberculosis may be associated with syphilis, but preserves its own pathological characters; that, although we are ignorant of the exact differential histological changes, there is sufficient evidence to show that there is a distinct association between syphilis and pulmonary disease; and that syphilitic phthisis is commonly interstitial. Whether the relation be one of cause and effect, or whether the process is simply a modification of ordinary tubercular phthisis, it is impossible at present to determine. The final adjustment of the theories concerning the specific etiology of tubercular phthisis may throw further light upon the etiology of syphilitic phthisis. That gummata may be found in the lungs is a well-established fact, and by some authorities is not considered rare.
The discussion of the etiology has already indicated the relation of the predisposing and exciting causes to pulmonary processes in connection with syphilis. In certain cases of syphilis the antecedent of pulmonary changes is a laryngeal or bronchial catarrh. The relation which an active virus in the blood sustains to the process is still subject to debate. Hutchinson writes as follows: "If the infected blood were the cause of the local phenomena, it is almost certain that such phenomena will be symmetrical, because the blood is equally supplied to both sides; such is the case during the secondary stage. If, however, the symptoms result from tissue-conditions, and the blood is at the time of the outbreak free, then there is a considerable probability that local influences may take a large share in evoking them, and they will be asymmetrical—evoked by some local cause."
The existence of gummata, then, does not necessarily show that there is any active virus in the blood, because their formation is sometimes symmetrical, sometimes asymmetrical.