When the catarrhal process is of longer duration, the capillaries and small veins become permanently enlarged; round cells are deposited between the epithelium and cellular tissue; the cellular tissue becomes hypertrophied; papillary elevations are formed on the vocal cords. The disintegration of the epithelium and the bursting of the tumefied muciparous glands lead to the formation of erosions and ulcerations; the chronic swelling and hypernutrition of the muciparous follicles to their destruction by cicatrization or simple induration; and to atrophy of the mucous membrane.
Many of the specific causes of inflammation of the larynx exhibit no peculiar alterations of their own. Scarlatina, measles, and exanthematic typhus are complicated with either a catarrhal (in most cases) or a diphtheritic laryngitis. Variola, however, has a peculiar form of its own, with red, pointed, whitish stains or nodules, consisting of a cellular infiltration or of a deposit upon or into the upper layers of the mucous membrane, composed of necrotic epithelia and pus-corpuscles or of coherent membrane. Hemorrhages or abscesses are but rare, and chondritis seldom results from it. Even syphilis has not always changes which are characteristic. The laryngitis accompanying it is often but catarrhal, without anything pathognomonic about it. But whitish papules consisting of granulation-tissue (plaques muqueuses), gummata often changing into sinuous ulcerations, particularly on the epiglottis and posterior wall of the larynx, also perichondritis with loss of cartilage and deep cicatrization, such as are not found in either carcinosis or tuberculosis of the larynx, are frequently met with. Typhoid fever shows different forms of laryngitis, from the catarrhal to the ulcerous. Epithelium is thrown off at an early period of the disease; erosions and ecchymoses follow; rhagades on the margins of the epiglottis, and a deposit on the anterior wall of the larynx and the vocal cords, consisting of epithelium and round cells, are frequent. That they should be mixed with micrococci and bacteria is self-understood. Not so that these bacteria are to be considered as the cause of the disintegration which is taking place, the less so as no specific typhoid bacterium has been demonstrated, and several varieties of them are found both in the mouth and in these ulcerations. These changes are apt to terminate in ulceration of the epiglottis and false vocal cords; these will extend in different directions, and to the deeper tissue down to the cartilage.
In tuberculosis, laryngitis is a frequent occurrence. In most cases it is secondary to the pulmonary affection, and due to the direct influence of the contagious sputum—according to Heinze, however, not to contagion, but to the influence of the infected blood. In other cases it appears to develop spontaneously, before any pulmonary affection is diagnosticated, and may then be due to some poison circulating in either blood or lymph. Tubercular laryngitis, according to Rindfleisch, commences in the excretory ducts of the muciparous glands. That this is so in a great many cases is undoubted. The first changes visible are small cellular subepithelial infiltrations or real subepithelial tubercles, which, while growing, undergo gaseous degenerations and ulcerate. These ulcerations are either flat and small or deeper with an infiltrated edge, and are apt to terminate in secondary nodulated infiltrations and abscesses. Large tumors are not met with, but oedema and phlegmonous inflammations are by no means rare.
ETIOLOGY.—The predisposition varies according to individuals, ages, and seasons. Some mucous membranes appear to be more sensitive than others. The hereditary transmission of peculiarities of structure of all or some tissues or organs is apparent, in the case of laryngitis, in the fact that many children in the same family or the children of parents who were sufferers themselves are affected. Children are more liable than adults, infants more than children: 20 per cent. of all the cases are met with under a year, 25 from the first to the second, 15 from the second to the third. Not many occur after the twelfth year. The narrowness of the infant larynx and the looseness of its mucous membrane afford full play to injurious influences, such as dust, cold and moist air, changing temperatures, hot vapors and beverages. Colds, though their nature and effects can hardly be said to be understood, are certainly amongst the main causes. Perspiring surfaces afford frequent opportunities. One of the principal causes is insufficient clothing—more amongst the well-to-do than amongst the poor. The latter have this blessing in their misfortune, that they are protected uniformly if at all, and have their skins hardened by exposure. The bare necks and chests, the exposed knees, the low stockings and thin shoes of the children of the rich, old and young, are just as many inlets of laryngeal catarrh, inflammatory disease, and phthisis. Persons suffering from nasal catarrh or pharyngeal catarrh are liable to have laryngitis. Thus, not only rachitis, with its influence on lymphatic glands and the neighboring mucous membranes, but also acute infectious diseases, such as whooping cough, measles, influenza, erysipelas, hay fever, tuberculosis, syphilis, typhoid fever, and variola, are as many causes of laryngitis. That over-exertion of the voice should produce laryngitis seems probable, but experience does not teach that those babies who cry most are most subject to laryngeal catarrh.
SYMPTOMS.—Acute laryngitis is a frequent disease, and has always been. Still, in 1769, Millar mistook it for a sensitive neurosis, considering it as identical with spasm of the glottis, and recommended antispasmodic treatment. Guersant understood its nature better. He first (1829) used the names false croup and stridulous laryngitis. Acute laryngitis is attended with but little fever in the adult, but with a high elevation of temperature in the young. In all, it yields a number of symptoms, part of which are uncomfortable only; others are liable to become dangerous.
Seldom without any catarrhal premonitory symptoms of other parts of the respiratory tract, sometimes, however, without any, there is a burning, tickling, irritating sensation in the larynx—a sense of soreness in it and the lower portion of the pharynx. Sometimes these sensations amount to actual pain, to difficulty of deglutition, and to the sensation of the presence of a foreign body. Speaking, coughing, cold air, increase the discomfort and pain. Hoarseness, sometimes increasing into aphonia, follows soon after, is seldom simultaneous with, the first appearance of cough, but lasts longer than the latter, which is, according to the severity of the case or the stage of the disease, changing between loose and dry, hoarse and barking. Inspiration is apt to become impeded, mainly in infants and children. In these it is often sibilant. It is followed by a reflex paroxysm of cough, with interrupted and brief expirations, during which the forcible compression of the thorax may result in cyanosis. The principal attacks are met with at night amongst children. Quite suddenly they wake up with a dry, barking cough, interrupted by considerable dyspnoea, which is great enough sometimes to give rise to much anxiety. They toss about or cling to a solid body, raise themselves on their knees, breathe with great difficulty, exhibit cyanosis in its different hues, perspire very freely, and yield all the symptoms of the strangulating attacks of membranous croup, its over-exertion of the sterno-cleido-mastoid muscles and supraclavicular and diaphragmatic recessions not excepted. These attacks occur but rarely during the day; on the contrary, well-marked remissions are quite common in the morning. Their occurrence during the night is best explained by the facility with which mucus will enter the larynx from above during the reclining posture, the increasing dryness of the pharynx during sleep, perhaps also the nervous influence depending upon the relative diminution of oxygen and increase of carbonic acid in the respiratory centre, leading to spasmodic contractions.
Some of these grave attacks of sudden dyspnoea are explained by the participation of the submucous tissue in the morbid process. When that occurs, adults also, who as a rule do not suffer from dyspnoea in laryngeal catarrh, are badly affected. The symptoms are rigor, high temperature, pain, hoarseness or aphonia, a barking cough, labored expectoration—which is sometimes bloody—dyspnoea, orthopnoea, cyanosis. In some cases, to which the name of laryngitis gravis or acutissima has been given, the symptoms grow urgent to such a degree that tracheotomy alone is capable of saving life.
Otherwise, the severity of the symptoms does not go parallel with the local lesions. Particularly in children, hoarseness, cough, and dyspnoea are liable to be grave, while the local hyperæmia is not intense at all. A pharyngeal catarrh is very apt to increase the suffering. Complications with tracheitis or bronchitis are liable to prolong the course of the disease and to render respiration—which is not accelerated in laryngeal catarrh—more frequent. Otherwise, the disease runs a favorable course. Remissions of the severe attacks which may occur in several successive nights take place in the morning. Expectoration, which in the beginning was either absent or scanty, becomes soon more copious and mucous; the hard, barking, loud cough grows looser with increasing secretion. In most cases the violence of the affection is broken in from three to five days, and the disease runs its full course in a week or two. But hoarseness may remain behind for some time; in rare cases aphonia has become permanent and relapses are frequent. Not infrequently children are presented who are reported to have had croup five or ten or more times. In some families all the children are subject to laryngeal catarrh, and hereditary influence cannot be doubted.
The very worst complication of laryngitis is oedema of the glottis. It affects both the mucous membrane and the submucous tissue of the larynx. It is met with on the inferior (posterior) surface of the epiglottis, in the ary-epiglottic folds, and on the false (inferior) vocal cords, the submucous tissue of which is of a very loose structure normally. Amongst its causes—which may be various (foreign bodies in the larynx, injuries, mechanical and chemical irritants of any kinds; typhoid, tubercular, variolous, syphilitic ulcerations; erysipelas of the neighborhood, inflammations of the parotids or tonsils, suppuration in the pharynx, thyroid body, and cellular tissue of the neck)—both catarrhal and croupous laryngitis are not at all uncommon. This is particularly so when they are complicated with cardiac and renal anomalies, pulmonary emphysema, and compression of the veins of the neck by glandular swellings; also with changes in the structure of the walls of the blood-vessels. The last-named pathological conditions are alone capable of giving rise to chronic oedema of the larynx, which is by no means so fatal, but still dangerous.
In glottic oedema the dyspnoea is both very great and very sudden. First, it is inspiratory only, but soon becomes both inspiratory and expiratory. The swelling is felt distinctly by the examining finger; the laryngoscope is neither required nor advisable.