Rheumatism.

Definition.—A constitutional disease, of unknown etiology, characterized by inflammation of the locomotor apparatus, accompanied by great pain and tenderness, with tendency to change from one part to another—metastasis.

Rheumatism is divided into acute, subacute, and chronic. Pseudo-rheumatism, into gonorrheal and muscular.

Etiology.—Many theories have been advanced from time to time to prove the specific character of the disease, each with a fair show of positive evidence to confirm the particular view held by the advocate. There are three principal theories to which the medical world has been generally committed, and each of which has had many supporters:

(1) The Chemical Theory.—This for a long time was the generally accepted factor in the production of rheumatism. In the metabolic changes that are constantly taking place, a perversion of the retrograde metamorphosis occurs, giving rise to lactic acid, and possibly other compounds, which so irritate the various tissues of the locomotor apparatus that rheumatism follows. The acid perspiration and urine seemed to confirm this view. This theory, however, is being largely abandoned, as it is now known that some cases of rheumatism show a defect in the acids of the body, and that such patients are benefited by an acid treatment. That, in many cases of this disease, there is an excess of lactic and uric acid, however, is well known.

(2) The Nervous Theory.—It is an established fact in pathology that joint troubles occur as a sequence to lesions of the nerves and nerve centers. Charcot, Brown-Sequard, and others have called the attention of the profession to this point. Dr. J. K. JMitchell, of Philadelphia, as early as 1831, called attention to joint changes following injuries of the spinal cord, and his son, Dr. Weir Mitchell, has written on the same thought.

(3) The Infectious Theory.—The belief that the cause is microbic in origin, therefore infectious, is receiving a large following. Various germs have been found in the blood-serum and synovial fluid of the affected parts, though no constant variety has been uniformly present. Recent experiments, in which cultures from organisms taken from rheumatic nodules reproduced polyarthritis and pericarditis in the rabbit, seem quite significant. The fact that it quite often occurs in epidemic form also tends to confirm the view that it is infectious.

Predisposing Causes.—Sex.—In young children, girls are more frequently affected than boys, while in later life the male sex is more liable, on account of more frequent exposure.

Age.—The most susceptible age is from fifteen to twenty-five years, though no age is exempt.

Season.—The months of February, March, and April, when there are sudden atmospheric changes, predispose to the disease.

Occupation.—All occupations which are attended by exposure to the weather, such as those of drivers, sailors, soldiers, and outdoor laborers, predispose to rheumatism, and those requiring great exertion, followed by rapid cooling of the body, as ironworkers, boiler-makers, foundrymen, yeast-makers, and brewers.

Heredity.—There is a hereditary tendency to the disease, and it is quite common to find several in a family rheumatic.

Sudden Exposure.—The chilling of the surface by sudden exposure in inclement weather is frequently traced as a causal factor in the disease. One attack of rheumatism predisposes to further attacks.

Pathology.—There are no characteristic changes peculiar to rheumatism, unless we except the lesions of the heart, where this organ becomes complicated. Most patients recover without permanent lesions of the joints, notwithstanding the great amount of swelling during the progress of the disease. During an attack, there is hyperemia of the joints and synovial membrane, attended by swelling of the joints and ligamentous tissue. There is often an increase of the synovial fluid, which may become turbid owing to the presence of fibrin flakes and leukocytes, though pus and blood are rarely found. There is marked anemia, the red corpuscles rapidly disappearing, while the hemoglobin may be reduced one-half and leukocytosis is quite common. In quite a large per cent of cases the serous membranes of the heart are involved, giving rise to endocarditis, pericarditis, and myocarditis; the left side is more frequently affected. The pleura and lung may also show changes, the result of complications.

The Eclectic Practice of Medicine, 1907, was written by Rolla L. Thomas, M. S., M. D.