(c) Tuberculous empyema is quite rare. It usually develops slowly and chronically without any material discomfort, and often occurs as a sequel to a serous effusion. It may lead to pyopneumothorax and to pulsating empyema in left-sided cases. The diagnosis is based on the existence of tuberculosis in one of the lungs or elsewhere. The effusion is often seropurulent, sometimes fetid from the beginning, or becomes fetid after operation. The pus may also become thick and greenish in color, from the pneuniococcic content. It is often difficult to distin guish the empyema of tuberculosis patients from tuberculous ernpyema (compare with the chapter on tuberculosis).
(d) Fetid empyema depends upon a previous or on an existing com munication of the pleural cavity with the external air which has af forded entrance to septic germs (pulmonary gang,rene, etc.). The pic ture of pyopneumothorax is produced by the formation of gas in the pus, which aids in diagnosis in so far as a tuberculosis pneumothorax can be excluded. The evil sometimes develops after typhoid fever, measles, or chronic otitis. As treatment, thoracotomy or resection of the ribs with irrigation are to be employed.
The diagnosis of pleurisy often presents difficulties in the child which are absent in the adult. Dry pleurisy is easily recognized as soon as pleuritic friction sounds are to be heard; these are, however, more frequently absent than in the adult. Soft friction sounds may present similarity to crepitant rfiles. Crepitant rales are heard only on inspira tion with one breath, are uniform, and often change after coughing. The isolated friction sounds are more apt to be less uniform, and are also heard on expiration, and have a tendency to appear over a circumscribed area. Pleurisy with effusion in older children is as easily diagnosed as in adults. The latency of pleurisy is not based on the nature of the dis ease but on the carelessness of physicians (Henoch). The great resistance of the dulness, the tliminished or abolished fremitus, the bronchial breath ing heard only softly, the accelerated, superficial, and in the beginning painful breathing, the expansion, and the very much impeded move ments of the affected half of the thorax, or the displacement of the neighboring organs, render the diagnosis easy.
The recognition of the disease in young children is often very diffi cult. Here, the existence, for instance, of a moderate dulness will often cause us for a long time to be uncertain whether a pleuritic effusion or Pulmonic consolidation is present. Shoulcl the child not favor us by
coughing or crying, it is often impossible in the youngest subjects to test the fremitus, the constant diminution of which constitutes one of the most important signs of an effusion. Furthermore, in children distinct bronchial breathing and bronchophony are often heard over ft recent effusion even of considerable degree. Finally, beside the pleurisy, bron chitic sounds, at times even amphoric breathing, are heard with rela tive frequency. In these difficult cases with indistinct fremitus and bronchial breathing the peculiar resistance of the pleuritic dulness can alone apart from an exploratory puncture render the diagnosis possible at the beginning in small effusions. Otherwise, we must take into con sideration the remaining symptoms against those diseases in question. In this respect croupous pneumonia, the broncho- and tuberculous pneumonia are the most important. The differential diagnosis of these has been considered in the respective chapters. Later on, the diagnosis is much facilitated by the observation of the course and the typical physical signs, and also by the manner of the increase and diminution of the dulness, and by the obliteration of the intercostal spaces, tbe pars vertebral dulness, the deficient displacement of the pulmonary borders, and the total filling up of the complimental spaces. I'or diagnosis, radioscopy nifty also be utilized which will show the displacement of the neighboring organs particularly- well.
Hydrothorax always develops in conjunction with other transuda tions, almost always bilaterally, and is afebrile, without pain and with out cough. Its level is changed by change of position. The rare echino coccus cysts and tumors of the pleura and lungs are very difficult to diagnose.
If the diagnosis of a pleuritic effusion seems to be established, the important question to be decided is whether a serous or purulent effu sion is present. In the above description of the disease those points in favor of a purulent or non-purulent nature of the effusion are suffi ciently brought out. To the great detriment of the patient empyema is often unrecognized when it runs an afebrile or subfebrile course and bronchial breathing is present over the effusion, both kind of cases occurring very frequently.