The diagnosis of pneumonia is usually- easily made in older children, since nearly all symptoms with the exception of the sputum are typical, —the same as in adults, VIZ: diminished and bronchial breathing, bron chophony, dulness, and increased vocal fremitus. On the other hand, the diagnosis in young infants presents many difficulties where chill, cough, and pain in the side are absent, herpes labialis occurring less frequently than in adults. Instead of these, abdominal pains and symp toms frotn other organs may preclotninate. It may readily be under stood that beginners usually do not think of pneumonia at all, and rather assume anything else (gastric fever, meningitis, etc.). This is quite pardonable, since the objective symptoms often are not present until from the third to the sixth day. This is particularly the case in apical pneumonia, which also in many other respects presents the most diffi culties for diagnosis, as is sufficiently shown by the above description of the t.lisease.
In bronchopneumonia the question usually hinges on whether only a bronchitis is present, or in addition thereto a pulmonary- consolidation; in other words, whether a bronchopneumonia is present or not. In croupous pneumonia the difficulty is mostly as to whether a pulmonary affection is present or not.
In cases where there is a sudden elevation and a continuous tem perature the possibility- of a croupous pneumonia must be constantly born in mind, even when no symptoms point directly to the respiratory apparatus. Indeed, pain and cough are frequently absent, and one is prone to attribute the accelerated respiration to the temperature. 'Usually, however, the characteristic grunting expiration is present, and also a somewhat clysmiceic (labored) respiration which directs our atten tion to the lungs. One must make it a rule to make daily examinations of the lungs in all eases of high temperature. By doing so, unimpor tant symptoms, whieh were not previously- present, will be promptly and correctly interpreted, thus avoiding delay in diagnosis of a croupous pneumonia, a suspicion of which is only sometimes aroused by the sud den decline of the temperature on the fifth to the seventh day-, when it is usually- easily established. Whoever does not make it a rule to search for croupous pneumonia (especially also over the scapulm), will at times overlook this disease, and perhaps only later will be able to properly estimate the previous condition by the occurrence of a purulent pleu risy; furthermore, systematic taking of the temperature is valuable for diagnosis, inasmuch as a high and continuous temperature is seldom_ seen under ant- other circumstances.
Bronchial breathing and bronchophony over a circumscribed area, where they were previously absent and which disappear again after a few days, are frequently the only pulmonary physical signs in central (especially in apical) pneun-mnia, and are sufficient to establish the diag nosis which often can be made with considerable certainty many days previous to the late manifestations of pulmonary consolidation, namely, by the sudden onset with high continuous temperature, and by the accelerated and somewhat elyspmeic breathing with grunting expira tion. The absence of bronchophony and bronchial breathing in pneu nionia is frequently due only to the fact that the infant breathes super ficially. Crying and coughing with the resulting deep inspirations will then cause these symptoms to become plainly manifest.
One should always remember that in percussing a crying infant, and especially if it is pressing down, that a slight dulness may be present over the lower and posterior portions of the lungs under normal condi tions. But this disappears again on inspiration, and therefore may be easily distinguished from a dulness resulting from a pathological condi tion. Furthermore, there is frequently found at the pulmonohepatic border behind and on the right side greater dulness than in the left. This is caused by the large size of the liver. Those who are inexperienced are apt to regard this relationship as dulness within the thoracic cavity-. The normal vesicular breathing readily shows, however, that no patho logical condition is present, and confirms the view that this dulness has its seat within the range of the liver. In small children the spinous pro cesses are counted with difficulty. It is more practical under these circumstances to determine the lower border of the lungs behind, accord ing to the ribs. It is normally found at the tenth rib in the posterior scapular line, and is easily determined by counting from the twelfth rib.
Owing to insufficient pulmonic findings, a differential diagnosis. must be made in many febrile infectious diseases in their beginning. When cerebral symptoms are present one readily thinks of meningitis. But tuberculous meningitis, which on account of its great frequency is likely to be thought of first, develops slowly; and, moreover, convulsions and stupor are not present in the beginning as in cerebral pneumonia, but come on later in the course of the disease. The temperature in tuber culous meningitis is mostly moderate and varying in character. The meningeal symptoms in croupous pneumonia are incomplete; irregular and retarded pulse, dilatation of the pupils, and paralysis, are almost always absent.