1. As mentioned under etiology, serolibrinous pleurisy rather infre quently attacks children under five years of age, but is also seen during the nursing period Occurring primarily, it is often ushered in as rap idly and violently as has been described. However, it often also appears secondarily, most frequently after croupous and bronchopneumonia, or acute rheumatism, and then after acute infectious diseases (measles, scarlet fever). It frequently begins inconspicuously and stealthily with out any material local symptoms. The physician is consulted because the child is becoming pale, thin, tired, and is without appetite, or because recovery does not seem to take place after an acute disease. Exami nation then usually reveals a considerable effusion. In general, the course is rapid and mostly terminates after 3-4 weeks, or at least after 2-3 months. Even in cases where the initial symptoms were severe and associated with high fever, the pain, temperature, and effusion, subside as early as weeks,. though not as rapidly as in croupous pneumonia. Acute plcuritis seems to be unusual, and sudden cleaths are very rare occurrences. Quite frequently the effusion is hannorrhagic in small children without being tuberculous, as in influenza, acute rheumatism, hacmorrhag,ie diathesis. The so-called rheumatic pleurisy is frequent in children of from 10-15 years of age. It often originates from an unknown cause, rarely after taking cold, more frequently after angina and acute articular rheumatism in which it is prone to appear bilaterally. The effusion is frequently free from bacteria.
Tuberculous pleurisy is much rarer in children than in adults. It often develops slowly and stealthily. The mononuclear lymphocytes are supposed to predominate (see tuberculosis).
During the first days, the temperature in serofibrinous pleurisy is usually pretty high, 39-40° C. (102-104° F.), and then during about the 2nd-3rd week, with an effusion remaining stationary, is apt to as sume a remittent, descending, type, and to disappear very gradually during absorption.
The pulse is very much accelerated during the febrile period. With displacement and compression of the heart and large trunks of vessels, it becomes small and weak, sometimes irregular. In more extensive effusions it may also be accelerated without fever, and bounds rapidly in height especially after slight exertion or motion.
Complications cvhich are not caused by some other underlying affec tion are rarely observed. Simultaneous peritonitis or pericardAis mostly depend on a common cause (tuberculosis, acute rheumatism).
Recovery in acute cases is usually complete, often, however, leaving adhesions of the pleural folds, which may produce diminished mobility of the lungs lasting for years or remaining permanent. Absorption fre quently takes place rapidly within 2-3 weeks and is accompanied by increased diuresis, though it often lasts very much longer. If the effu
sion becomes very large and is not removed in time, it may cause death from mechanical pressure on the heart and large vessels afflict cyanosis and pulmonary oedema, or by cardiac thrombosis and embolism of a pulmonary artery. If the effusion is absorbed slowly, a thickening of the connective tissue of the pleura (pleuritic thickening) often remains for many years, and this usually continues to produce dulness and dimin ished breathing below posteriorly. In prolonged and chronic cases, especially, where a large effusion has been permitted to undergo absorp tion for a long time without the aid of medical skill, the lung which is bound down for months by the thickened and shrinking pleura never becomes fully expanded. A diminution of the respective half of the chest results tretrecissement), with a narrowing of the intercostal spaces, scoliosis, and approximation of the scapula to the vertebral column. At the same time the heart and the liver are drawn towards the contracting pleural cavity. The sound lung presents vicarious emphysema. Even after many years' duration, retrogression of the retrecissement, pleuritic thickening, and expansion of the lung, are still possible in children under favorable conditions. Otherwise, a chronic interstitial pneumonia with bronchiectasis frequently develops.
2. Pur ulent pleuriny (empyema) plays a much more important role in practice among children than serous pleurisy. The two forms are scarcely to be distinguished by physical examination, since the (edema of the thoracic wall which i.s often mentioned as point of differentiation is also usually absent in empyema. On the other hand, the origin (Ind course of the disease frequently places us in a position to recognize with great certainty the purulent nature of the plettrisy. Very often the effusion is purulent from the beginning, as in pytemia, gangrene of the lungs, scarlet fever, and croupous pneumonia occurring, during the nursling age. The transition of a serous effusion to an empyema may take place within a few days, and the large bacterial and lymphocyte content in a recent effusion (for instance, during a croupous pneumonia) mill often permit us to foresee this transition. A purulent pleurisy usu ally presents more violent symptoms than the .serous variety. The effusion increases rapidly and may soon involve one side entirely. The discomforts are greater; palpation and percussion are often inore pain ful. The general condition is much more disturbed. Within a short time, there is a loss of strength and loss of appetite, pallor and anannia and emaciation. Sweats appear. Bilateral empyema is not altogether rare. Absorption of the effusion may fail to take place even within 4-6 weeks. In long continuance, enlargement of the liver and spleen sometimes occurs.