When tuberculosis follows empyema the temperature, if it had subsided, rises to between and or higher every evening, falling again to between 99° and 100° in the morning. The child loses flesh, colour, and strength more rapidly than the condition of his chest is sufficient to ex plain. His face is haggard and careworn ; his skin harsh and dry ; often diarrhoea comes on ; sometimes he vomits ; his belly swells; and an attack of basic meningitis usually brings the illness rapidly to a close.
Complications.—Besides tuberculosis and amyloid disease of organs (which have been already alluded to), there are other complications which may be present in cases of pleurisy. Pericarditis is not uncommon as an accompaniment of the pleural inflammation. This subject is referred to elsewhere (see page 158). Moreover, serous inflammation in the chest some times spreads upwards from the peritoneum. More often, however, it pen etrates downwards through the diaphragm to the abdominal cavity. It is then usually fatal (see page 685).
Diagnosis.—Ou account of the resemblance of its physical signs to those of pneumonia, pleurisy is often mistaken for that disease. The difficulty in making the distinction is due principally to the absence of vocal frernitus in the child ; to the occasional loud breathing tubular breathin which is often heard over the seat of dulness ; and to the crackling character of the friction, which suggests rather an intra-pulmonary crepitation than a pleural rub. In order, to distinguish between the two diseases we must take into account the mode of invasion, the nature of the symptoms, and the character of the physical signs ; for in all these points great differences are to be observed.
The occurrence of pain in the side and fever, followed after an interval by cough, is characteristic of pleurisy. In pneumonia cough is usually present from the beginning, and pain in the side, unless pleurisy accom pany the inflammation of the lung, is moderate or absent. The after symptoms also are different. In pleurisy the cough is dry and painful ; the pulse-respiration ratio is unaltered ; the face is pale or congested at first, afterwards straw yellow ; and there is little loss of muscular strength. In pneumonia the cough occurs in short hacks, accompanied in the older children by the expectoration of rusty sputum ; the pulse-respiration ratio is perverted ; the face has a bright flush on the cheeks ; and muscular prostration is a marked feature. The physical signs also are distinctive.
In pleurisy the chest, even if not enlarged to the measuring tape, is square in outline ; the heart's apex is displaced ; the dulness is complete, the note being perfectly flat, and the sense of resistance to the finger extreme ; the respiratory sounds, although they may be as tubular as in a case of typical pulmonary inflammation, are always less loud at the base than above ; and the crackling. friction has not the "puffy " character of pneumonic crepita tion. The chief difference, however, consists in the fact that in an ordinary case of pleurisy the abnormal physical signs are found both at the back and front of the affected side. In pneumonia there is no displacement of the heart's apex ; the dulness is not complete ; the sense of resistance, although greater than natural, is only moderately increased ; the resonance of the voice at the angle of the scapula is never regophonic ; and the physical signs, unless the inflammation occupy the apex of the lung, are limited to the anterior or posterior aspect of the chest, and are only in very extreme cases found over the whole of the affected side.
Between an ordinary case of pleuritic effusion and an ordinary case of lobar inflammation of the lung the differences are so great, that there is little difficulty in making the distinction. But to decide between a local ised pleurisy and a case of lobar pneumonia is not so easy. Still, even here, by attention to the mode of invasion and the character of the symp toms, and by remarking that, although limited to oue aspect or one region of the chest, the percussion-note is completely toneless, the sense of re sistance is extreme, and the weak breath-sound is not accompanied by cre pitation at the borders of the dull area (for, in localised pleurisy friction is rarely to be heard), we can usually come to a satisfactory conclusion. The very fact of these physical signs continuing for a considerable time un changed is in itself a strong argument in favour of the pleuritic nature of the complaint. Dr. Wilks, indeed, lays it down as a rule that local dul ness with distant tubular breathing, or absence of breath-sound, persist ing after an inflammatory attack in the chest, indicates the presence of a lo cal empyema ; and if no adventitious sounds accompany the respiration, we may, no doubt, commit ourselves to this diagnosis without hesitation.