THE MIASMATIC THEORY OF RHEUMATISM.
In rejecting the neurotic theory of rheumatism we reject the view that the disease is due to disturbance originating independently of a special poison.
Iu rejecting the lactic-acid theory we reject the view that the rheumatic poison is generated within the system.
The only alternative view is that this poison enters the system from without.
Of such poisons there are two kinds—the contagia and the mias mata. What knowledge we possess regarding the nature and mode of action of these poisons has been got less from a study of the poi sons themselves than from a study of the phenomena to which they give rise.
The essential properties of the fevers to which the contagia give rise are as follows: 1. They are communicable from the sick to the healthy.
2. They have a fixed and definite period of duration.
3. One attack, as a rule, confers immunity from a second.
But rheumatic fever is not communicable from the sick to the healthy; it has no fixed period of duration; and one attack confers no immunity against a second. As rheumatic fever bears no analogy to the contagious fevers its poison cannot be regarded as a contagium.
In studying malarial fevers the facts which force themselves most prominently on our attention are as follows : 1. They are most apt to occur in low-lying, damp localities, in certain climates, and at certain seasons of the year.
2. Some people are more liable to be attacked than others.
3. They have no definite period of duration.
4. They are not communicable from the sick to the healthy.
Now we cannot fail to see that these are quite the attributes of acute rheumatism. It is most common in temperate climates, at cer tain seasons, and in damp, low-lying localities ; it has no fixed period of duration; it is not communicable from the sick to the healthy ; some people are more liable to suffer than others ; and its poison, we have seen reason to believe, enters the system from without. But the analogy between rheumatic fever and the common malarial fevers does not end here. A still further analogy may be traced in their clinical histories.
1. Malarial fever is irregular in type, and characterized by varia tions in its course. So is rheumatic fever.
2. Profuse perspirations characterize the course of malarial fevers ; so they do that of rheumatic fever.
3. During the course of malarial fevers the urine is loaded with prates; so it is in rheumatic fever.
4. One attack of malarial fever seems to render the system more liable to its recurrence; the same is true of rheumatic fever.
5. Malarial fevers often leave an impress on the system which renders the sufferer liable to disturbance and the recurrence of some of their symptoms from slight causes. Rheumatic fever often has the same effect.
6. Unless arrested by treatment malarial fevers are apt to have a protracted and uncertain course; so is rheumatic fever.
7. The course of malarial fever is speedily arrested by large doses of the cinchona compounds. The course of rheumatic fever is as speedily checked by large doses of the salicyl compounds.
It is evident that the rheumatic poison, both in its history and in its effects on the system, bears a closer analogy to the poison of malarial fevers than to any other morbific agency.
The poison which gives rise to malarial fever, and that which gives rise to rheumatic fever, are distinct and separate agencies ; but the analogies noted in the natural history and course of the ailments which they respectively produce are sufficiently close to indicate the probability of their being allied in nature and in mode of action.
The existence of some points of analogy between intermittent and rheumatic fever did not escape the notice of some of the older ob servers. Haygarth "thought that there were several analogies be tween an ague and a rheumatic fever. In both diseases the urine lets. fall a similar lateritious sediment. In intermittent as well as rheu matic fever the blood when let is covered with an inflammatory crust.
The pain and fever of rheumatism have certain periodical, though not quite regular, paroxysms and intermissions." Acute rheumatism is generally regarded as a continued fever; but except its prolonged duration, it possesses none of the characteristics of such a fever. The continued fevers have a regular and continuous course, a typical and characteristic range of temperature, and a defi nite period of duration; often they terminate by a distinct crisis. Rheumatic fever has none of these characteristics; its course is irreg ular; it has no definite period of duration, and no typical range of temperature; it never terminates by a distinct crisis, and it is im possible to say how long a case may last if left to pursue its natural course. Seeing a man suffering from one of the continued fevers one can foretell with tolerable certainty the future course and duration of the malady. In rheumatic fever this cannot be done; to-day the temperature may be and the joints acutely inflamed; a. couple of days later the temperature may be 100° and the joints much better; a few days afterward the acute symptoms may have again returned, and the fever be as high as ever; and so it may rise and fall, and rise and fall every few days for several weeks in succession, or the disease may come to a termination at the end of eight or ten days. Irregu larity is the prominent feature of both the course and the duration of acute rheumatism. "Irregular pyrexia is joined with irregular perspirations" (Scadamore). It is evident that this fluctuating course is more like that of remittent and intermittent, than that of the con tinued fevers.
There are reasonable grounds, it will be seen, for regarding rheu matism as malarial in nature, and its poison as a miasm which enters the system from without. The further prosecution of our inquiry necessitates a preliminary investigation into the nature of malarial poisons generally.