CROUPOUS (FIBRINOUS) PNEUMONIA Croupous pneumonia constitutes a typical cyclic disease, well known to every layman by the term "inflammation of the lungs." On account of the regular participation of the pleura it is also called pleura pneumonia, and on account of the nature of its appearance primary, genuine pneumonia. Less properly, the disease is designated as lobar pneumonia since bronchopneumonia also appears in a lobar form in addition to a number of other acute pulmonic inflammations having a different etiology (partly streptocoeci and staphyloc.oeci), and which also often deviate in their clinical course by typhoid symptoms, by angina, prolonged eourse, termination by lysis, tendency to abscesses, and gangrene. It is justly desirable to separate these forms of pneu monia as atypical pneuntonias from the eroupous variety (Aufrecht), and in the future we will certainly also learn to differentiate them more readily clinically.
Etiology.—Croupous pneumonia is an infectious disease, a fact which has been made absolutely certain by the researches of Frankel and Weichselbaurn. Its cause is the Frankcl-Weichselbanin diplococcus pnennionitc (often merely called pneumococeus), which in the majority of eases of typical croupous pneumonia is found in great numbers in the lungs, often in pure culture, frequently also with strepto-, staphylo coeci, Friedlander's and colon bacilli. The pneunmeoccus is also regularly found in the complicating diseases of croupous pneumonia, in pleurisy, pericarditis, peritonitis, meningitis, otitis, arthritis, and osteomyelitis. Moreover, all these affections may also be called forth apparently pri marily by the pneumococcus. Often it may also be demonstrated by proper methods in the blood of patients suffering from pneumonia, (23 per cent. of CaSe,,, SellOttlellier). In pneumonia, the pneumococcus is frequently found in the peritoneal cavity without peritoneal symp toms (Stooss). Besides the pneumococcus, but much more rarely-, the Friedlander pneumonia bacillus may also produce the picture of a croupous pneumonia, perhaps also the streptococeus mucosus.
The Frankel pneumococcus, a slender, oval, often lance-shaped, pointed coccus, appears mostly as a diploeoccus, at times arranged in rows of 4-6, and is surrounded by- a capsule (without it in the culture).
It is found in large numbers in the affected portions of the lungs, as well as in the sputum of pneumonia patients; less numerous but very fre quently in the nose, pharynx, and bronchi of healthy individuals. It stains readily with aniline colors, according to Gram. It grows only at the temperature of the blood in the culture (agar-agar, blood serum). For authentication, rabbits are inocculated, which rapidly- die from sepsis.
While at the present time croupous pneumonia is generally re garded as a bacterial infectious disease, nevertheless it is certain that in the developing of the same, the predisposing causes, which formerly were solely held responsible, play a very- important part. Duerek has shown by experiment on animals, that for the development of pneu monia. a definite traumatism is necessary; inhalation of dust, or more particularly a cold. In children we also not infrequently see a pneu monia develop in the course of a severe cold. under the influence of which the domiciled pneumococei may develop undisturbed. Duerck found pneumococci twelve times in thirteen healthy children. For the development of pneumonia, therefore, no new infection is at all required.
This relationship also explains without any trouble the development of pneumonia as the result of an injury (blow on the chest), which has been observed from time to time (also by myself), and in which the period of incubation is only of a few hours' duration.
The seasons of the year exert a marked influence on the frequency. Everywhere in Middle Europe the maximum number of cases is found in the spring, the minimum in the fall (see Fig. 81). Besides the injurious changes of temperature during the spring, the lasting impairment of the respiratory organs during the winter is principally responsible. During the spring of the year, there is an accumulation of cases, appearing al most epidemically as the result of grippe. Epidemic and endemic occur rence is also seen at other times. Jiirgensen straightway designates pneutnonia as a "house-disease." Pneumonia very frequently occurs secondarily in grippe; less fre quently in measles, typhoid, and other infectious diseases.