This has given us two other data of great importance and value, namely, that while the immediate and greatest peril is over when the membrane has become loosened and the temperature has begun to subside, in both ordinary throat and in laryngeal forms of the disease, the patient is by no means out of danger. While the antitoxins poured out by his body have completely defeated the invading toxins in the open field of the blood, yet almost every tissue of the body is still saturated with these latter and has often been seriously damaged by them before their course was checked. For instance, nearly two-thirds of our diphtheria cases, which are properly examined, will show albumin in the urine, showing that the kidney-cells have been attacked and poisoned by the toxin. This may go on to a fatal attack of uremia; but fortunately, not commonly, far less so than in scarlet fever. The kidneys usually recover completely, but this may take weeks and months. Again, many cases of diphtheria will show a weak and rapid pulse, which will persist for weeks after the patient has apparently recovered; and if the little ones are allowed to sit up too soon, or to indulge in any sudden movements or muscular strains, this weak and rapid pulse will suddenly change into an attack of heart failure and, possibly, fatal collapse. This, again, illustrates the saturation of the poison, as these effects are now known to be due in part to a direct poisoning of the muscle of the heart itself, and later to serious damage done to the nerves controlling the heart, chiefly the pneumo-gastric. Moral: Keep the little patient in bed for at least two weeks or, better, three. He will have to spend a month or more in quarantine, anyway.
Last of all, and by no means least interesting, are the effects which are produced upon the nervous system. One day, while the child is recovering, and is possibly beginning to sit up in bed, a glass of milk is handed to him. The little one drinks it eagerly and attempts to swallow, but suddenly it chokes, half strangles, and back comes the milk, pouring out through the nostrils. Paralysis of the soft palate has occurred from poisoning of the nerves controlling it, caused by direct penetration of the toxin. Sometimes the muscles of the eye become paralyzed and the little one squints, or can no longer see to read.
Fortunately, most of these alarming results go only to a certain degree, and then gradually fade away and disappear; but this may take months or even longer. In a certain number, however, the nerves of respiration, or those controlling the heart-beat, become affected, and the patient dies suddenly from heart failure.
This strange after-effect upon the nervous system, which was first clearly noticed in diphtheria and syphilis, has now been found to occur in lesser degree in a large number of our infectious diseases, so that many of our most serious paralyses and other diseases of the nervous system are now traceable to such causes.
These effects of the diphtheria toxin are also of interest for a somewhat unexpected reason, since it has been claimed that they are effects of the antitoxin, by those who are opposed to its use. Every one of them was well recognized as a possible result of diphtheria long before the antitoxin was discovered, and every one of them can be readily produced by injections of diphtheria bacilli or their toxin into animals.
It is quite possibly true that there are more cases of nerve-poisoning (neuritis) and of paralysis following diphtheria than there were before the use of antitoxin, but that is for the simple and sufficient reason that there are more children left alive to display them! And between a child with a temporary squint and a dead child few mothers would hesitate long in their choice.
CHAPTER XI
THE HERODS OF OUR DAY: SCARLET FEVER, MEASLES, AND WHOOPING-COUGH
Why is a disease a disease of childhood? First and fundamentally, because that is the earliest period at which a human being can have it. But the problem goes deeper than this. There is no more interesting and important group of diseases in the whole realm of pathology than those which we calmly dub "the diseases of childhood," and thereby dismiss to the limbo of unavoidable accidents and discomforts, like flies, mosquitoes, and stubbed toes, which are best treated with a shrug of the shoulders and such stoic philosophy as we can muster. They are interesting, because the moment we begin to study them intelligently we stumble upon some of the profoundest and most far-reaching problems of resistance to disease; important, because, trifling as we regard them, and indeed largely just because we so regard them, they kill, or handicap for life, more children in civilized communities than the most deadly pestilence. Measles, for instance, according to the last United States census, causes yearly nearly thirteen thousand deaths, while smallpox causes so few that it is not listed among the important causes of death. Scarlet fever causes sixty-three hundred and thirty-three deaths, as compared with barely five thousand from appendicitis and the same number from rheumatism. Whooping-cough causes ninety-nine hundred and fifty-eight deaths, more than double the mortality from diabetes and nearly equal to that of malarial fever.