INFLAMMATION OF THE PLEURA. 269 



they be situated upon the costal pleura and penetrate deeply, external 

 perforation of the empyema may take place, and in fortunate cases, 

 especially if the lung remain capable of redistention, recovery may be 

 the result. In similar manner, a penetration of the empyema into the 

 lung and its discharge by way of the bronchi sometimes happen, but a 

 recovery in such instances is rare. 



SYMPTOMS AND COURSE. Dry pleurisy has no symptoms, or, at 

 least, if it have symptoms, they cannot be distinguished from those of 

 the disease which it accompanies. We sometimes find adhesion of the 

 entire pleural surface in the bodies of persons who never have been 

 seriously ill. Extensive and rigid adhesions of the pulmonary and costal 

 pleurae hinder the two surfaces from sliding upon one another, and 

 thus prevent a uniform expansion of the lung during inspiration (see 

 vicarious emphysema). The consequence often is a slight dyspnoea, 

 which is only felt when unusual bodily exertion or other cause excites 

 a demand for an increased supply of oxygen. 



Pleurisy icith scanty fibrinous exudation is accompanied by 

 severe piercing pain when a breath is drawn ; the suffering produced 

 by the limited and slow movement of the pleura, during ordinary 

 breathing, is far greater than that arising from the strong and rapid 

 motion of forced respiration. Coughing and sneezing are especially 

 painful to the patient, as these acts compress the inflamed pleura from 

 within. In like manner a pressure upon the ribs and intercostal mus- 

 cles affects the pleura immediately, and greatly increases the pain. 

 The respiration of the patient is shallow and cautious. The body is 

 generally bent toward the affected side, as this attitude lessens the 

 tension of the intercostal muscles and its inflamed covering. Besides 

 the pain, some patients have a distinct sensation of friction, or of 

 scratching at some point of the thorax. There is also cough, as a rule ; 

 although cases now and then are observed where there is absolutely 

 no cough, and it has not as yet been determined satisfactorily whether 

 the cough is a result of reflex action from the inflammatory irritation 

 of the pleura, similar to that arising from irritation of the bronchial 

 mucous membrane, or whether it is due to a complication of pneu- 

 monia or bronchitis with the pleurisy. The pleurisy with scanty 

 fibrinous exudation, unless accompanied by extensive and severe 

 inflammation of the lung, is usually unattended by fever, or other 

 serious derangement of the health. Many patients never even keep 

 their room, and often go on foot to the clinic, or to the office of their 

 physician, for medical aid. 



We have already stated that the pleuritic stitch, which is one of 

 the most painful symptoms of croupous pneumonia, and which indubi- 

 tably owes its origin to the almost constant complication of the latter 



