Herpes is of such common occurrence in pneumonia as to possess diagnostic im portance. The appearance of this erup tion is especially valuable in cases of cen tral pneumonia and in those instances in which the limitation of the lesion may render the diagnosis doubtful. It occurs early in the disease and is usually dis tributed about the lips and nasal aim.
The nervous system is frequently dis turbed. In mild cases mental dullness, headache, and marked prostration occur. In the severer forms of the disease delir ium may be most marked. In most cases these nervous symptoms are due to the infection and not to any pathological changes in the cerebral meninges. In other instances, however, inflammation of the meninges, as demonstrated at the autopsy, accounts for their occurrence. During life the differentiation between the two classes of cases is attended with much difficulty. Hyperpyrexia is ally associated with those cases in which marked cerebral perturbation occurs. In drunkards an attack of delirium tremens is very apt to characterize the onset of the disease, and as the symptoms of pneu monia may be absent systematic tion of the lungs in such cases is impor tant. In children convulsions may occur at the onset of the disease and may then replace the chill.
Nervous symptoms are perhaps more frequent in pneumonia than in typhoid fever. From the onset the nervous feat ures may so dominate the scene that the local lesion is likely to be overlooked. These cases may be grouped under three headings: I. The cerebral pneumonia of children, in which the disease sets in with a convulsion; there is high fever, headache, delirium, great irritability, muscular tremor, and perhaps retraction of the head and neck. The diagnosis of meningitis is almost invariably made and the local affection may be over looked. 2. Cases in which the disease sets in with acute mania. Pulmonary features are frequently masked in those of delirium tremens, and error is certain to occur, unless it is made an invariable rule to examine the chest in such cases. 3. Cases with toxic features, resembling those of uremia. Without chill, cough, or pain in the side, the patient may de velop fever, a little shortness of breath, and then gradually grow dull, heavy, and within three days there may be a condition of profound toxremia, with low, muttering delirium. Osier (Maryland Med. Jour., Mar. 12, 'fiS).
Fever is almost always present and is more or less typical. Its onset is abrupt, quickly following the chill, and its fas tigium is rapidly attained. Its range is high, reaching 104° or 105° F. or higher, and is subcontinuous except when its course is interrupted by the distinct and marked remissions known as pseudo crises. These remissions are so decided as to lead to the hope that the actual crisis is about to take place; exacerbation of the fever follows, however, and the dis 'ease pursues its course, interrupted, per 'haps, by one or more pseudocrises. The
'duration of the fever varies and in un 'complicated cases usually terminates in from five to nine days. It may, how ever, cease earlier, more frequently later. Defervescence is usually critical; occa sionally, however, it is prolonged and may take place by lysis. In one of the series of cases at the Philadelphia Hos pital convalescence did not begin until the nineteenth day, although no com plication accounting for the sustained febrile temperature could be detected. Frequently there is a decided rise in the temperature immediately before the crisis; this is the so-called "precritical rise." In cases terminating fatally a so called preagonistic rise in the tempera ture may occur, which at times reaches 108 degrees or higher. This preagonistic rise was noted in 9 of the Philadelphia Hospital cases.
Physical Signs. — INSPECTION. - The patient usually lies upon the infected side: a decubitus very likely to be as sumed in those instances in which pain is a common symptom. By assuming this attitude the respiratory excursis upon the affected side is limited and the rubbing together of the inflamed pleural surfaces reduced to a minimum. Evidences of dyspncea are frequently to be observed and the degree of cyanosis and dilatation of the nasal aim, with the play of the auxiliary muscles of respiration, may constitute an important evidence of the extent to which the air-space is limited. In severe cases cyanosis of the cheeks and lips may be most marked. It is not un common for one cheek alone to show cyanosis, and this usually corresponds with the side of the lesion. No alteration in the contour of the chest is to be de tected, but increased frequency of respi ration is to be noted and limitation of the respiratory movement upon the affected side is often most marked. In the early stages of the disease this limitation is to be ascribed to the involuntary fixation of the chest-wall on account of the intense pleuritic pain. Later, when consolida tion has supervened, this lack of expan sion is due to inability to expand that portion of the lung. At the onset but little alteration in the vocal fremitus is to be detected. In proportion as con solidation develops, however, vocal fre mitus is increased. Early in the disease a pleuritic fremitus is not uncommonly detected. Absence of vocal fremitus must not lead to a rash conclusion of the non-existence of pulmonary consolida tion, or that the latter is associated with a pleural effusion, as the voice-vibrations are sometimes temporarily prevented from being transmitted to the lesion by the occlusion of a large bronchial tube with a mass of mucus.