II. Symptomatic or Metastatic Parotitis

Symptomatic, metastatic, malignant, or suppurative parotitis, as the condition is variously designated, is an inflammation of the parotid gland which occurs during the course of different grave acute diseases, is usually unilateral, and terminates in suppuration, or much more rarely in gangrene, of the gland involved.

ETIOLOGY.—It may occur in association with typhus, typhoid, relapsing, puerperal, and scarlet fevers, or with the plague, measles, dysentery, cholera, and pyæmia, springing into notice at different periods of the course of these affections, which may be regarded as predisposing causes. The exciting cause is perhaps mechanical in nature—namely, the excessive dryness of the mucous membrane of the mouth so common in the severe fevers. This dryness may lead to an occlusion of the orifice of the parotid duct, with retention of the saliva, which fluid, undergoing decomposition, may act as an irritant, producing inflammation, and finally suppuration, of the glandular tissue. This is a likely enough explanation of the causation in some cases, but dryness of the mouth is such a uniform symptom in fever, and suppurative parotitis such a comparatively rare complication, that it cannot be a very active or common cause. Nevertheless, it is impossible to fix upon any other direct cause, though the altered condition of the blood in the conditions mentioned must not be lost sight of as an important etiological factor.

ANATOMICAL APPEARANCES.—The character of the pathological lesions have been well established, owing to the frequent opportunities that arise of examining the diseased gland at different stages of the inflammatory process. When the inflammation has lasted a short time, a day or two, the tubes and acini of the gland are seen on section to be swollen and reddened, and the connective tissue infiltrated with serum and yellowish-red in color; a fluid, either viscid, ropy, grayish in color, or more purulent in character, fills the duct, and may be forced out into the mouth by stroking it in the direction of the orifice. If of several days' longer duration, purulent softening will be noticed in the centre of the acini; this gradually extends until each acinus is converted into a little sac of pus. Then the inter-acinous connective tissue breaks down, and the multiple, minute, purulent collections become converted into a single large abscess or into two or more smaller ones. Next, the pus seeks an outlet. The position of pointing may be on the cheek or in the external auditory meatus—a very common location; again, the abscess may break into the mouth, the pharynx, the oesophagus, or into the anterior mediastinum, the pus burrowing its way along the sheath of the sterno-cleido-mastoid muscle.

While the parotid abscess is forming, suppurative inflammation is apt to be set up in the masseter, pterygoid, and temporal muscles, and from these positions the pus forces its way upward to the temporal or zygomatic fossæ. The periosteum of the neighboring bones, and even the bones themselves, may become involved, and sometimes the cranial bones are partially destroyed, and there is an extension of the inflammation to the brain or its membranes. The middle ear may participate in the general destruction, and the patient is left permanently deaf, if indeed he escape with his life.

The lymphatics, veins, and nerves traversing the parotid are affected by the suppuration in the gland. Irritation of the lymph-vessels results in swelling, tenderness, and suppuration of the lymph-glands. Thrombi form in the jugular vein and its branches, and by breaking down lead to septicæmia and ichorization of the sinuses of the dura mater. The nerves resist for a long time, but seem to act as paths of conduction of the inflammation, the facial nerve leading it to the ear, and the branches of the trifacial to the brain. When gangrene of the gland takes place, the traversing nerves as well as the gland elements are rapidly destroyed.

SYMPTOMS.—Symptomatic parotitis, occurring during the course of any of the diseases already named, produces no change in the general symptoms; if, on the other hand, it occurs during convalescence, the onset is marked by a moderate elevation of temperature and increase in the frequency of the pulse, by thirst, loss of appetite, and sluggish bowels. The tumor, which occupies the same position and thrusts outward the ear-lobe as in mumps, is hard, dense, well defined, and the seat of considerable pain until suppuration takes place, when the latter subsides greatly. The skin over it is red, hot, and tense, and there is much tenderness and little or no pitting on pressure. After the abscess has formed there is well-defined fluctuation on palpation, and at the position of pointing the skin becomes very thin and assumes a bluish-red hue. Gangrene of the gland is manifested by the cadaverous odor, blackening of the skin, the formation of a cavity, and the discharge of ichor and shreds of tissue. The alteration in the expression, the pain in the ear, the difficulty in moving the jaw and in swallowing, are as constantly present here as in idiopathic mumps. It must not be forgotten, though, that when the disease arises during the course of any of the severe infectious diseases, the brain may be so overcome that the subjective symptoms are frequently not complained of.

The course is usually rapid, the abscess pointing on the fourth or fifth day after the appearance of the parotid tumor; occasionally, however, the inflammatory process is much slower, extending over a period of several weeks. The course is also much protracted when secondary abscesses form in other parts of the gland or in the surrounding tissues, when the abscess is transformed into an ichorous cavity, and when gangrene sets in. Ordinarily, where the pus is evacuated by spontaneous rupture or by incision the abscess heals quickly by granulation, leaving the gland enlarged and indurated for some time.

THE PROGNOSIS depends upon the gravity of the original disease, the period of the disease at which the complication occurs, and whether or no mortification sets in. When the vital processes are greatly impaired by the primary disease, the onset of the parotitis, trifling in itself, may prove sufficient to determine a fatal result. The danger of such a result is much increased, too, if the inflammation begins in the earlier stages or during the height of the disease which it complicates, while if it commences during convalescence by far the most frequent result is recovery. Gangrene of the gland involves great risk of life—a risk which increases in proportion to the early date of its onset in the course of the original disease. Even when the gangrenous process ends in recovery, the face is much distorted, the hearing is lost in the ear, and the facial muscles are paralyzed on the affected side. Bilateral symptomatic parotitis has naturally a graver prognosis than the unilateral form.

DIAGNOSIS.—The disease is readily distinguished from idiopathic mumps by the history, the less marked degree of the enlargement and surrounding oedema, the greater degree of pain and tenderness, the hardness of the tumor, the red discoloration of the skin covering it, and the termination in suppuration. Further, it never displays an epidemic tendency.

TREATMENT.—The general treatment of this form does not differ from that of the disease it complicates, though the employment of stimulants in increased quantities may be indicated.

Before the first appearance of tumefaction of the parotid the introduction of a probe or canula into the duct of Steno, associated with pressure on the gland from the outside, may, by forcing from the duct a collection of mucus or muco-pus, abort the inflammation. If this is unsuccessful, a poultice should be applied over the gland to encourage suppuration and pointing externally. As soon as the abscess points the pus must be evacuated by an incision, and, as this has a tendency to close again, a piece of lint must be kept between the lips of the wound.

The enlargement and induration left after the healing of the abscess require the application of tincture of iodine or of compound iodine ointment to the surface.

When gangrene occurs it demands the same treatment, both local and general, as when it is seated elsewhere.