INFLAMMATION OF THE PAROTID, ETC. 4.55 



it is chiefly or so.ely caused by serous exudation. Although we have 

 said above that the affection probably proceeds from a catairh of the 

 gland-duct, still there is no doubt that the swelling chiefly affects the 

 interstitial substance and the connective tissue about the gland. The 

 swelling usually extends far beyond the borders of the gland The 

 development of oedema about the inflamed gland-ducts is not at all 

 strange ; it corresponds exactly with observations made in analogous 

 conditions. Infiltration, with firm fibiinous exudations and suppura 

 tion, rarely occur in parotitis. We do not know whether the suppura- 

 tion proceeds from the gland itself or the interstitial substance ; but it 

 is most probable that there is just the same state of affairs as in sup 

 purating symptomatic parotitis. (See below.) 



Symptomatic parotitis begins, according to the careful observa- 

 tions of Virchow, with decided hyperaemia, which causes the gland 

 and interstitial substance to appear infiltrated and swelled Changes 

 in the gland-ducts scon begin ; a tough, filamentous, whitish, or yellow- 

 ish substance, which soon becomes purulent, collects in them. Even 

 at the second or third day the microscope shows that it contains pus- 

 corpuscles, with numerous salivary corpuscles. If the disease pro- 

 ceeds, the lobules of the gland soften and break down ; this process 

 begins within, so that at one time the lobules represent cavities filled 

 with pus. Finally, the tunica propria is also destroyed, and the inter- 

 stitial tissue begins to suppurate ; this suppuration may extend rap- 

 idly, and become a diffuse phlegmonous inflammation. In this case a 

 large parotid abscess forms ; more frequently the gland-tissue only is 

 destroyed, and as the interstitial tissue remains intact, numerous small 

 abscesses are formed. Occasionally also there are extensive destruc- 

 tion and gangrene of the gland-tissue and interstitial substance ; the 

 inflammation and suppuration may spread from its original seat in vari- 

 ous directions and cause dangerous results. It most frequently attacks 

 the neighboring connective tissue, and the masticatory muscles lying 

 in it, the periosteum of the maxillary, temporal, and sphenoid bones, or 

 even the bones themselves. Where the disease is very severe, it 

 occasionally passes from the bones to the membranes of the brain, and 

 the brain itself or to the internal and middle ear. This propagation 

 of inflammation and suppuration to the cerebral membranes and the 

 internal ear may take place along the blood-vessels and nerve-sheaths*, 

 as well as through the bones. Finally, in some cases parotitis induces 

 phlebitis and thrombus of neighboring veins, especially of the anterioi 

 and posterior facial and external jugular veins ; the disintegration of 

 these thrombi may cause embolism and septicaemia. 



SYMPTOMS A>T> COTJBSE. In idiopathic parotitis, as in other in- 

 flammations, the 'ocal symptoms are often preceded by slight fever 



