Part 128

DEFINITION AND DESCRIPTION.--Whooping cough has been {837} characterized as an acute contagious affection, occurring usually in childhood, though it may occur at any age, and lasting several weeks. It is manifested usually by malaise, catarrh of the respiratory tract, and subsequently by a convulsive cough occurring in paroxysms, the peculiarity of which consists of a series of forcible expirations, followed by a sonorous inspiration or whoop, which may be repeated several times.

At the beginning of these paroxysms of coughing, there are evidences of slight laryngeal irritation, attended by an effort at suppressing the cough; then follow gradually increasing and more audible inspirations, which become more and more difficult. The child is agitated, the face becomes pale, and the countenance has a mingled expression of supplication and fear. If it is old enough it will seize the nearest object for support. As the spell advances, the eyes become suffused and prominent and the loose tissue surrounding the orbits appears puffy and congested. Finally, the paroxysm reaches its height; the child, with a livid countenance, with veins standing out like cords, gives a succession of violent expiratory efforts, followed by a long inspiratory whoop. The same is repeated several times, until finally almost complete cyanosis takes place; the spasm relaxes, a glairy, tenacious mucus runs from the mouth, the contents of the stomach are vomited, and the child falls back exhausted. The lividity of the countenance is succeeded by a deathly pallor; the face still appears swollen and puffy beneath the eyes; the tears course down the cheeks, and frequently hemorrhage occurs from the eyes, nose, ears, or throat, owing to the terrific strain upon the circulation. As soon as the child has recovered from the fatigue of the paroxysm all is apparently over, and were it not for the characteristic expression of the eye, which is pathognomonic in a well-advanced case, nothing would be noticed to even suggest the disease when uncomplicated. The voice is clear; there is little or no elevation of temperature.

The paroxysms which have given the name to this disease can only be likened to an epileptic convulsion, which by gradually increasing cyanosis is self-curable, the carbonized blood finally bringing about an anæsthetic effect. The severity of the paroxysms is by no means in proportion to the local catarrh, which latter may be superficial and slight, not to be detected during life by the most careful laryngeal examinations, and only after death by the aid of the microscope. The frequency and intensity of the paroxysms are dependent in a measure upon the degree of excitability of the nervous system, which of course differs in individuals. It is evident that the success of treatment must be powerfully influenced by this circumstance, and it is partly owing to it that there are so many opinions as to the value of remedies in this disease.

The complications are usually dependent upon outside causes, and have nothing to do with the poison proper of whooping cough, as far as we can tell. There are some which depend on an inflammation of the mucous membrane, which may be limited to any portion of the respiratory tract or may extend throughout it. Complications may arise from mechanical obstruction to inspiration by the swollen mucous membrane or from plugs of tenacious mucus, which may cause pulmonary collapse and favor the development of catarrhal pneumonia, and later even of phthisis; or from impediments to free and easy expiration, whether from spasm of the bronchioles, from forcible compression of the thorax through reflex {838} nervous irritation, or from other obstructions, all of which tend to produce emphysema. Disturbances of the circulation, in the brain or elsewhere, may proceed from thrombi or emboli and give rise to complications which will render fatal an otherwise mild form of the disease. The invariable disturbance of nutrition which accompanies every disease affecting the nervous system is apt to show itself in the breaking down of products which are simply inflammatory. Vomiting may be a most serious complication, both from its immediate and remote effects. It may be due to gastric catarrh, or more frequently to irritation of the pneumogastric nerve.

ETIOLOGY.--Very numerous theories have been advanced as to the nature of this interesting disease. Hufeland, Lebenstein, Pinel, Jahn, Todd, Cullen and a host of others have regarded it as essentially a neurosis. By many others it has been supposed to be due to a lesion of the brain or of its membranes, but careful investigation has established the fact that there is no lesion in whooping cough at all constant or characteristic. By still others, and especially by Gueneau de Mussy, it has been regarded as essentially an affection of the tracheo-bronchial glands, a bronchial adenopathy, causing irritation of the pneumogastrics and of their bronchial branches by pressure of the enlarged glands. We have, however, seen many post-mortem examinations of the bodies of children who have died of measles, where marked enlargement of these glands was constantly found, but where no symptoms of whooping cough had been present. There are indeed many features of the disease which seem inexplicable on any other theory than that the essential cause of whooping cough is a specific poison, and such is the view now generally adopted. This poison is capable of being carried by fomites, though as it is highly infectious it is often communicated through the atmosphere, and is most frequently conveyed from individual to individual. Dolan, who has recently published a very interesting and valuable monograph on this affection, quotes Linnæus, who ascribed it to the irritation of insects, as the author of the modern view that whooping cough is due to the presence of a peculiar microbe, though it must be conceded that as yet it has not been discovered. Most observers hold that the contagium is not in the blood, but that it resides in the secretions of the respiratory passages, and is most virulent during that stage of the disease when the secretion is abundant. Letzerich states that he has {839} succeeded in producing whooping cough in rabbits by inoculating the trachea with the sputa of the human subject. Dolan obtained similar results by injecting the nasal secretions, and also by compelling rabbits to inhale air impregnated with decomposing sputa and vomit of patients suffering with the disease.

The following brief statement of his conclusions may be quoted as presenting the most important facts concerning the pathology of the disease:

1st. Pertussis depends on a specific poison or contagion; this is universally admitted.

2d. This contagion is active and highly infectious; this is also granted.

3d. The contagion is analogous to the contagia which produce splenic fever, measles, scarlatina, variola, etc.

4th. It has a peculiar determination to the lungs.

5th. Like all other contagia, it has its period of activity and decline.

6th. The period of greatest activity is in the first and second stages.

7th. Pertussis runs a regular course like measles, scarlatina, variola, etc., and rarely attacks a person but once.

8th. It may thus be classed among zymotic diseases.

9th. The fact that there is no primary pathognomonic morbid change supports this view.

10th. There are various secondary lesions which are characteristic, as ulcerations of the frænum linguæ.

11th. The mode of death harmonizes with this view.]

I do not, however, feel entirely satisfied in adopting the view that the contagium of whooping cough resides alone in the mucous membranes of the air-passages. Children have been known to be born with the disease, the mother having suffered from it some time previous to confinement. The following case occurred under my own observation: Mrs. F----, the mother of two children, was in her eighth month of pregnancy; the two children had at the time a very severe attack of whooping cough, which required the constant attendance of the mother. She, though an extremely intelligent woman, belonged to the poorer classes, and had no one to assist her at this trying time. One day she complained that the movements of her child in utero had entirely changed. Suddenly, without any previous motion, the child would become very active; the force of its movements was such as to make hazardous any attempt on her part to walk in the street. The suddenness with which the movement would come on would oblige her to seize the nearest object for support. This continued until the child was born. Shortly after labor my attention was called to the infant, which had a curious attack, it became deeply cyanosed, seemed asphyxiated, as it were, for a moment, had no convulsions, and within a few seconds resumed its normal breathing and the circulation seemed once more established. I saw the child in several of these attacks; its health did not seem to be impaired, and without treatment, within a few weeks they disappeared altogether. The mother insisted upon the fact that the child had whooping cough, and the absence of the characteristic whoop was the only thing that prevented the diagnosis from being positive. This would show--and there are enough cases on record to warrant our basing an opinion upon them--that the contagium of whooping cough is found not alone in the matters expectorated, notwithstanding the statement of Dolan and others that their experiments failed to show its existence in the blood.

It must not be forgotten, in reference to cases which seem to have arisen without any exposure to the specific poison, that the characteristic whoop is not always present, and that consequently the true nature of mild cases of the disease which may infect other individuals may have been overlooked. Childhood probably acts as a predisposing cause, though the disease occurs at all periods of life, and as it usually occurs but once in the same individual, it is clear that the apparent diminution of susceptibility in later years may be largely due to the fact that most persons have had the disease in childhood. More children are attacked from one to five years, and the disease is more prevalent in summer and fall months. Causes which, like exposure to inclement weather, give rise to irritation of the bronchial mucous membrane, or diseases which, as measles, are accompanied with catarrhal symptoms and susceptibility of the bronchial mucous membrane, also may serve as predisposing causes. Sex appears to exert some positive influence. Of 360 cases of pertussis by Dessau, the total number of males were 154, that of females 206. Girls are more {840} frequently attacked than boys, in proportion of 2 to 1.50; this seems true at all ages; this statement is substantiated by Unruh of Dresden, based on an analysis of 1952 cases.

SYMPTOMS.--The disease begins usually with an ordinary catarrh, preceded by malaise and slight laryngeal irritation, which may be overlooked; in fact, during the first stage there is nothing to attract special attention, unless a direct history of exposure be known and suspicion be aroused on that account. Meigs and Pepper state that the earliest period at which they have known the distinctive whoop of the disease was three days, though in a great many instances it was delayed as late as three weeks. The same authors state that the ordinary duration of a paroxysm or kink is from one-fourth to three-fourths of a minute. They mention a case where the paroxysm lasted fifty-five minutes. Ordinarily they number about thirty-five or forty during the twenty-four hours at the height of the disease, differing greatly in individuals. Their number is most frequent in the course of the third or fourth week, after which they remain stationary, and then gradually decline. The paroxysms may occur spontaneously, or they may follow some irritation, either direct or reflex, or they may be induced by nervous excitement. Toward the end of the attack, after the catarrhal irritation has greatly subsided, or in fact has entirely disappeared, the paroxysmal kinks may be provoked by irritation of the fauces, and also by nervous excitement; and there is no question but that at this time they can be controlled by will-power. In many cases a distinct relapse occurs after the disease has been apparently cured.

Dolan believes the phenomena of the cough or kinks to be due, as suggested by Laennec, to a "spasmodic condition of the muscular or contractile fibres of the bronchi and their branches." He remarks that the lungs are supplied from the anterior and posterior pulmonary plexuses, formed chiefly of branches from the sympathetic and pneumogastrics. The filaments from these accompany the bronchial tubes upon which they are lost. Irritation of these nerves is said to have the effect of producing contractions of the bronchial canals sufficient to expel a certain quantity of air. If this theory is true, it helps us in explaining why the large, mediate, and smaller bronchi are closed during the expiratory stage of the paroxysmal cough of pertussis. The general opinion seems to be that the pneumogastric nerve is not inflamed, as has been asserted by some.

The highly sensitive condition of the nervous system, which is probably in a great measure intensified by the anæmia, and by the interference with nutrition due to the disturbance of the circulation by the cough, will show itself in many ways, and even when no secondary nervous affections complicate the attack or follow it. Some time will elapse after the disease has passed away before the child will recover its self-control, or its nutrition will show the influence of a healthy nervous system. The total duration of the affection is said to vary from six weeks to three months in ordinary cases; though probably, if active treatment could be instituted early enough and kept up with thoroughness, there is no specific disease more capable of being shortened in its course than the one under consideration; this remains, however, for future statistics to decide.

During the second stage of the disease the symptoms are sufficiently {841} marked to attract attention and render a diagnosis easy to make. Frequently the catarrh seems to extend to the bronchioles, and gives rise to symptoms that are alarming; and the intensity of the paroxysm will cause the engorgement of the blood-vessels to get relief in profuse hemorrhage; this is the period for caution. Complications may arise, the strength may fail, the secretions may become too abundant, and asphyxia may ensue; emphysema may show itself, or catarrhal pneumonia may gradually supervene.

The period of decline is very gradual; the secretions become less in quantity and more viscid, the paroxysmal cough is less frequent, but may at times be equally severe, the child's strength is usually exhausted, and its nutrition is greatly impaired. The expected paroxysm throws it into a state of intense nervous excitement; it is sleepless--in fact, worn out. Probably at this period of the disease treatment will show the most marked results, and the long lists of sedatives, tonics, etc. which are presented to us by their zealous advocates owe much of their popularity to their value at this stage of the disease. The catarrhal symptoms are the first to subside; the nervous disturbances remain for some time, and gradually fade, and the constitutional symptoms, or those from exhaustion, are the last to leave the patient.

Strange as it may seem, the heart appears to suffer but little in the long run from the great strain upon it; the palpitation and irregularity of its actions are not followed by structural changes as a rule, though we may state that feebleness of the circulation has remained in most of our bad cases for some months after recovery.

As regards the ulceration of the frænum linguæ, which has given rise to so much discussion as to its exact value as a symptom of this disease, our own experience leads us to believe that though it is nearly always present in the severe cases, its almost invariable absence before dentition and in milder cases shows it to be of traumatic origin. Roger's exhaustive report before the French Academy supported this view, and showed how clearly it is caused by the violent rubbing of the frænum on the free border of the incisors. On the other hand, Delthil of Paris and Blake of England believe that it is a pathological feature of the disease. The former reported cases in which it occurred before dentition. The ulcer is not always found on the frænum linguæ, but is found on either side of it. Bouffier noted severe cases of ulceration in children who had no teeth, but he attributed it to the injury produced by the mother in detaching the mucus with the finger.

Examinations of the urine have been carefully made by many observers. The appearance of sugar, about which so much has been said, does not seem to be constant, or even very frequent. Out of 50 cases, Dolan found traces of it in but 13. This coincides with our experience also, for we have frequently tested the urine in seven cases with negative results. Since, as is well known, irritation of the pneumogastric centre may cause glycosuria, it was at one time attempted to show that the paroxysms in whooping cough were due to congestion of the pneumogastric nerves, a condition which is said to have been occasionally found in this disease. Dolan says he has never seen hemorrhage from the kidneys during the course of whooping cough, nor blood in the urine.

MORTALITY.--It is an extremely difficult matter to reach, with any {842} degree of certainty, the true mortality of this affection. Meigs and Pepper say: "Of the 208 cases observed by ourselves, 143 were simple, all of which recovered;" and, again, "Some form of complication occurred in the 65 of the 208 cases observed by ourselves; of these 65, 12 died." The mortality seems greater under five years; thus: Of the 9008 deaths attributed to it in the United States during the census year ending June 1, 1870, the number of persons under one year of age was 4424, and 8396 were under five years. There were 1784 deaths from it recorded in Philadelphia from 1860 to 1876; of this number, 1724 were under five years of age. The census of the United States for 1880 gives a return of 11,102 deaths from this disease.