10 Guy's Hospital Reports, 3d Series, xix. 320.
No type of bodily conformation or temperament can be described that certainly indicates a proclivity to acute articular rheumatism; nor is there any change in the constitution of the tissues or fluids of the body by which the proclivity may be recognized. We infer the existence of the inherited predisposition—the innate bias—when rheumatism is found in the family history; when acute rheumatism or cardiac disease, or chorea not produced by mental causes, occurs in childhood; when the first attack of acute articular rheumatism is succeeded by subsequent attacks; and especially when the intervals between the attacks are short. Goodhardt has recently furnished valuable, but not conclusive, evidence to prove that in children obstinate headaches, night-terrors, severe anæmia, various neuro-muscular derangements, such as torticollis, tetany, muscular tremors, stammering, incontinence of urine, recurring attacks of abdominal pain, with looseness of the bowels quickly succeeding a meal, the cutaneous affection erythema nodosum, are indications of a rheumatic bias or predisposition.11
11 Guy's Hospital Reports, 3d Series, xxv.
There is some basis for the opinion that residence in damp, cold dwellings predisposes somewhat to acute articular rheumatism, although not at all to the same degree that it does to the chronic articular and muscular forms. Chomel and Jaccoud especially have insisted that it will gradually create a predisposition to the disease, even if it has not been inherited. All pathologists agree that cold is the most frequent exciting cause of acute articular rheumatism, and that it is especially effective when applied while the body is perspiring freely or is overheated or fatigued by exercise. There is no necessary ratio between the degree of cold or its duration and the severity of the resulting rheumatism. A slight chilling or a momentary exposure to a current of cold air will in some act as powerfully and as certainly as a prolonged immersion in cold water or a night spent sleeping on the damp grass. This circumstance, together with the fact that cold applied in the same way may also produce a pharyngitis or a bronchitis, a pneumonia or a nephritis, etc., is held to indicate that the cold acts according to individual predisposition; and Jaccoud, Flint, and others maintain that unless a rheumatic proclivity exists cold will not produce an attack of the disease under consideration. I doubt that we are yet in a position to assert that absolutely, although the weight of argument is in its favor. Let it suffice to say, that while a prolonged residence in a cold, damp dwelling may gradually develop a predisposition to rheumatism, a short exposure to cold will be likely to induce an attack of rheumatism if the predisposition exist.
There are other influences which may be regarded as auxiliaries to cold in exciting an attack, as they seem to increase the susceptibility of the patient to its operation: they establish what has been felicitously called a state of morbid opportunity. Such are all influences that reduce the resisting powers of the organs and organism, as bodily fatigue, mental exhaustion, the depressing passions, excessive venery, prolonged lactation, losses of blood, etc. It is probably in such a manner that local injuries (traumatism) sometimes appear to induce an attack of rheumatism. A blow on a finger (Cotain), the extraction of a tooth (Homolle), a hypodermic injection (ibid.), etc., may act powerfully in some persons upon and through the nervous system, and by lessening their resisting power may favor the overt manifestation of the rheumatic predisposition. But doubtless some such cases have been examples of mere coincidence.
There are certain pathological and even physiological conditions during or after which an inflammatory affection of one or several joints closely resembling acute articular rheumatism more or less frequently arises. Thus, during the early desquamating stage of scarlatina a mild inflammation of the joints of the hands and feet, and frequently of the large articulations as well, is very often seen, and it is attended with profuse perspiration, with a condition of urine like that of ordinary acute rheumatism, and occasionally with inflammation of the heart or pleura. During convalescence from dysentery an affection of a single or of several articulations resembling rheumatism has been noticed, and the two affections have even alternated in the same patient. That singular epidemic disease dengue is attended with a polyarticular affection closely resembling acute articular rheumatism, occasionally pursuing a protracted course, and not seldom leaving after it a cardiac lesion. In hæmophilia polyarticular and muscular disorders frequently arise which closely resemble, and appear to be sometimes identical with, ordinary acute articular and muscular rheumatism. Gonorrhoea too is often associated with a febrile polyarthritis, and rarely with an endocarditis at the same time. In the puerperal state an inflammation of one or several articulations is not unfrequently observed (puerperal rheumatism).
Respecting the real nature of these polyarticular inflammations very much has to be made out; and it must suffice at present to say that while many of them are of a pyæmic nature, as some examples of puerperal and scarlatinal arthritis, in which pus forms in or about the joints and in the serous cavities and viscera, some of them are no doubt examples of genuine rheumatism occurring in persons of rheumatic predisposition, which have either been induced by the lowering influence of the disease upon which they have supervened, or by the accidental coincidence of some of the other causes of acute rheumatism. There remains, however, the ordinary form of scarlatinal arthritis, which so closely resembles true acute articular rheumatism in its symptoms, course, visceral complications, and morbid anatomy that it cannot be said that the two affections are distinct and different. And much the same appears to be true of the articular affection of dengue. Yet so frequently does the articular affection accompany scarlatina and dengue respectively that it cannot logically be referred to a coexisting rheumatic predisposition, and must be a consequence of the disturbing influences of the specific poison of those zymotic affections per se.
PATHOLOGY.—The pathology of acute articular rheumatism is a very much debated question, and is not at all satisfactorily known. Hence a mere statement of the most prominent theories now held by different pathologists will be given.12
12 The reader may consult with advantage Dr. Morris Longstreth's fourth chapter in his recent excellent monograph upon Rheumatism, Gout, and some Allied Disorders, New York, 1882.
The latest modification of the lactic-acid theory of Prout is founded upon the modern physiological teaching that during muscular exercise sarcolactic acid and acid phosphate of potassium are formed, and carbon dioxide set free, in the muscular tissue, and that cold, acting on the surface under such circumstances, may check the elimination of these substances and cause their accumulation in the system. This view, it is held, explains why the muscles and their associated organs, the joints and tendons, suffer first and chiefly, because the morbific influence is exerted upon them when exhausted by functional activity; and it further accounts for the visceral manifestations and the apparent excess of acid eliminated during the course of the disease. The circumstance that in three cases of diabetes (Foster,13 Kuelz14) the administration of lactic acid appeared to induce polyarticular rheumatism favors the idea that acid is the materies morbi in rheumatism.