Synonyms:—Pertussis; tussis convulsiva.
Definition:—A specific highly contagious disease, characterized by a cough which is distinctly paroxysmal, the paroxysms beginning abruptly with a rapid succession of short hacks until the breath is entirely exhausted. The forcible inspiration which then occurs is accompanied by a conspicuous, prolonged crowing or whooping sound, from which the disease derives its name.
Etiology:—The disease is caused by a micro-organism, the exact character of which is as yet unknown. The presence of this, results in catarrhal inflammation of the respiratory tract and an irritation of the pneumogastric nerve. Bartholow, quoting Rosenthal, claimed that the micro-organism irritates the filaments of the superior laryngeal nerves. The disease occurs at any age but is most frequent before the seventh year, and is thought to occur more frequently in females than in males. It is more prevalent in winter and in early spring, but will occur at any time of the year and is not uncommon in the late summer or early fall. The period of incubation is about eight days, although it varies from four to fourteen.
The disease is transmitted by direct contact with a patient while he is coughing. It is questionable if the infectious principle is conveyed in any other manner. It is thrown through the air and transmitted by the sputum directly into the face and air passages of an unaffected individual, although it is not impossible that it may be carried on the clothes. An attack of the disease usually renders the patient immune to future attacks, as it is only in rare instances that an individual will have the disease twice. The disease is probably contagious from the time the cough begins until it ceases, whether its marked characteristics are present or not, but it is more readily conveyed while the disease is at its height and during the whooping period. A child seems to be more susceptible after an attack of measles, from which fact efforts have been made to establish a relationship between the two diseases. It is probably true that the diseased membranes after measles afford a soil in which the germ of whooping cough can more readily take root.
Symptomatology:—At first there are evidences of an ordinary nasal catarrh, with a mild bronchial cough, but the fact that the cough occurs in paroxysms is not sufficiently conspicuous to attract attention. After two or three days, if the temperature be registered, it will be found that it is slowly increasing each day, though not always with perfect regularity or present at all hours of the day. The temperature will not exceed 100.5° F. or 101° F., and after from three to seven or ten days the temperature may abate. At this time, the second stage, the distinctly paroxysmal stage develops. The first stage described is called the catarrhal stage, which may last from five to ten days. The second stage may last from one to three weeks, and is then followed by the stage of decline. As the paroxysmal stage approaches the cough increases, and will be found to be out of proportion to the other evidences of disease, which are determined by physical examination. The cough is worse at night, disturbing the sleep. Vomiting occurs from the cough and as a result of the loss of its food, the child becomes weakened, is disinclined to play and is fretful and irritable. As the whooping or distinctly paroxysmal stage approaches, the cough becomes more violent, inducing extreme redness of the face, distorted countenance and protuding eyes. If the child is lying down, upon the occurrence of the paroxysm, he will cry out as if in fear, will rise to a sitting posture and cling to any one near as if imploring help. If he is at play, he will run to his mother or nurse, being warned in time by certain premonitory sensations which are not described. The paroxysm at first is composed of a few hacks, as the lungs are probably nearly emptied of air; these are followed by a distinct whooping inspiration which is not long, but which more fully fills the lungs with air. There is then a long succession of rapid hacks until the breath is entirely exhausted, followed by a long, harsh, resonant whoop, which is followed by a cry of distress or apparent alarm and perhaps an effort at vomiting. There will be two or three such periods in a single paroxysm, during the last of which the child may cough up a quantity of glairy tenacious mucus which is with difficulty dislodged. As the paroxysms increase in severity, during the progress of the disease, the redness of the face increases until there is more or less cyanosis, with extreme fulness of the capillaries of the face and head, resulting often in epistaxis or hemorrhage from the ears, eyes and rarely from the bronchial tubes. The features are puffed, swollen and dusky in color, the eyelids swollen with extravasations of blood in the conjunctivae and occasionally in the retina. The action of the heart is greatly increased and the pulse becomes rapid, weak and easily compressible, especially in the later stages.
These paroxysms may occur only in the night, in the milder forms, or upon the decline of the disease, or there may be thirty or forty during a period of twenty-four hours. Between the paroxysms the child has complete rest, and in mild cases there are but few evidences of disease. The spasmodic stage in severe cases will last two or three weeks. In milder forms and in those modified by treatment, it may last only one week, or there may be but a few nights in which the characteristic whoop occurs. In other materially modified cases there may be an entire absence of the whoop, the diagnosis of the disease depending upon the persistency of the cough and by the presence of an epidemic or the knowledge of previous exposure.
In the stage of decline in uncomplicated cases all the symptoms gradually abate, the whooping ceases, the paroxysms occur with less frequency and the strength of the patient slowly improves.
Among the not unusual complications which appear, an ulcer upon the fraenum linguae occasionally occurs as a result of rubbing of the tongue upon the lower incisors; the heart may be weakened and in rare cases is dilated, the pulse showing corresponding weakness at all times; from failure to retain food, as well as from extreme violence of the muscular exercise, during the paroxysms, and the consequent shock to the nervous system the child becomes very weak and occasionally anemic, and occasionally leukocytosis develops with a mild form of albuminuria.
Diseases of the respiratory organs are among the most frequent complications. Bronchitis is very common in the earlier stages of this disease, and this may be quickly followed with broncho-pneumonia, and this, in a rare case, may be complicated by an attack of pleuritis. Compensatory emphysema is common from the increased respiratory efforts, and this may be followed by rupture of air vesicles and consequent interstitial emphysema. This in rare cases is extreme and becomes a serious complication. So great is the nervous irritation in occasional cases that convulsions occur. These result in cerebral or meningeal complications, and death follows. Cerebral hemorrhage from capillary rupture has frequently occurred, resulting in paralyses which may assume the form of monoplegia, paraplegia or hemiplegia.
Diagnosis:—The pathognomonic phenomenon in diagnosis is the whoop. This, however, is often entirely absent, when the diagnosis must be made by the knowledge of previous exposure; by the presence of an epidemic, or by the intractable character of the cough—its persistence— with no apparent result from the usual methods adopted for the control of severe cough. Another evidence of the disease, is the characteristic swollen appearance of the face and eyes, the puffy edematous condition, and the discoloration of the face. While this condition in whooping cough closely resembles the same condition in measles, there is but little difficulty in distinguishing the former from the latter disease.
Prognosis:—The prognosis depends upon the age of the patient. In children under two years of age it must be classed as a grave if not fatal disease. Its gravity, however, depends largely upon the complications. Foreign statistics show a mortality of twenty-six per cent, under one year of age, and of fourteen per cent between one and two years of age. From two to five years of age the mortality does not exceed three per cent. In England the disease is ranked among the most serious of the infectious diseases, which attack the children of the poor. With care and proper treatment, and with proper hygienic environment, the mortality is greatly reduced, and in uncomplicated cases the mortality should be low.
Treatment:—The influence of remedial measures and medicines in this disease have been universally disappointing, no specifics have as yet been discovered. The use of antiseptic gargles and sprays and the inhalation of antiseptic vapors at the onset of the disease, or during the catarrhal stage, have frequently aborted the disease or modified its character, thus confirming the opinion of its microbic origin. So common is the disease and so frequently devoid of serious complications that its gravity, its real seriousness is not appreciated either by the physician or by most people.
The patient must be confined in a warm room, with a uniform temperature, in which the air is kept constantly moist from boiling water. The course suggested in bronchitis or in croup, for generating large quantities of steam at regular intervals, is available where the room is heated by a furnace. This is done by dropping a hot brick or a piece of red hot iron into a wooden vessel of boiling water. To this a small piece of unslaked lime may be added or an ounce of vinegar, or a few drops of the oils of turpentine or of eucalyptus. This is an important measure and must not be neglected, as it will greatly decrease the paroxysms and conduce to easy and sufficient respiration. In the initial stage of the disease I have used belladonna with better results than any other remedy. The benefits of this agent in this disease have long been recognized. I administer a mixture made by adding ten drops of the official tincture to four ounces of water, in dram doses every hour, to children above five years of age. In younger children it should be given in half-dram doses. Where the secretions are deficient, and especially in older children, it may be given in the syrup of tolu. Where the secretions are excessive, I give it in larger doses every two hours, alternated every hour with one grain of alum dissolved in simple syrup, syrup of tolu or wild cherry. This has given me the most satisfactory results.
In those cases where there is much nervous excitability, with violent paroxysms, the bromids will be serviceable. If there is much heart weakness, the bromid of ammonium may be given, but usually the bromid of sodium will produce the most desirable results. Asafoetida has had an excellent reputation in the past for this class of cases, as it exercises a sedative effect upon the nerve centers. Lobelia has been advised, and there is no doubt that if we were able to distinguish carefully we would find a class of cases in which this remedy was superior to others. It must be given in small doses, frequently repeated, and no nauseating influence must be produced. Castanea vesca has been lauded in the past, but little proof is recorded as to its efficacy. Drosera will control the cough in a few cases, but its influence, however, is more apparent upon the after cough. It terminates the paroxysms and leaves the patient free from cough, materially assisting in the upbuilding of the patient. It has been given during the entire progress of the disease, when the bronchial secretions were deficient, with the result that the paroxysms occurred less often and were materially modified. The camphor monobromate is a remedy of much service where there is nervous irritability with extreme sensitiveness, and where there is nausea and extreme restlessness, with persistent fulness of the cerebral circulation, especially if the extremities are cold, it will give good results. From one to three grains may be given every two or three hours. A remedy that was quite popular among our older physicians was nitric acid. With these patients the mucous membranes are often dark red, and the secretions are deficient; if the tongue has a peculiar deep red or carmine color the agent will act to a better advantage. The acid may be added to syrup, in the proportion of one dram of the officially dilute acid to four ounces of syrup. This may be given in dram doses in a little water every hour or two.
Jamaica dogwood is advised, in doses of from two to five minims, every two hours. I have not had an opportunity to thoroughly test it. If it is possible to administer quinine to patients suffering from this disease, there are cases which seem to be satisfactorily influenced by this remedy. It can not be given to infants with advantage.
The inhalation of antiseptic vapors has accomplished good results in this disease. The vapor of eucalyptus is in common use, and patients have been subjected to the inhalation of ordinary illuminating gas and to an atmosphere which has been previously charged with a small quantity of sulphurous acid gas. The use of carbolic acid or peroxide of hydrogen in the form of a vapor, used with an ordinary vaporizer, are of service.