RHEUMATISM (from the Gr. rheuma, a flux) is a blood-disease in which inflamma tion of the fibrous tissues is the most marked characteristic, It occurs either as an acute or as a chronic affection; there is, however, no distinct line of demarkation between the two, and the latter is often a consequence of the former.
Acute rheumatism is indicated by general febrile symptoms, redness, heat, swelling, and usually very intense pain, in and around oue or more (generally'several, either sim ultaneously or in succession) of the larger joints, and the disease shows a tendency to shift from joint to joint or to certain internal fibrous membranes, and especially the per icardium; rheumatism being the most common origin of pericarditis, ashes been already shown in the article on that disease. The pulse is strong and full, there is headache, hut seldom delirium, unless the heart is affected; the tongue is covered with a creamy thick fur, the tip and edges being red; the urine is turbid, and abnormally acid; and the skin is bathed in a copious perspiration, with so characteristic a smell (resembling that of sour milk), that the physician can often recognize the disease almost before he sees the patient. The joints are extremely painful, and the pain is much increased by pres sure, and consequently by movement which gives rise to internal pressure. Hence the patient lies fixed in one position, from which he dares not stir. There are two varieties of acute rheumatism. In one, the inflammation commences not in the joint, but near It, and attacks the tendons, fasch, ligaments, and possibly the muscles themselves. This format is termed fibrous or diffused rheumatism. In the other variety, the synovial mem brane in the joint becomes affected, and an excess of fluid is poured into the joint, dis tending the membrane, and making it bulge out between the spaces intervening between the various tendons, ligaments, etc., round the joint. It is the knee-joint which is most commonly affected in this way, and fluctuation may readily be perceived on apply ing the hands to the two sides of the knee. In this form, which is called synodal rheu matism, the swelling and redness come on sooner, and are more marked than in the for mer variety. The fibrous is by far the most severe form, and it is to it that the previous sketch of the most marked symptoms chiefly applies. In the, synovial form, the fever
is less intense, the tongue less foul, the perspiration far less profuse, and the membranes of the heart are much less liable to be attacked. It is to this form that the term rheu matic gout is often applied, and it is by no means inappropriate, because synovial rheu matism forms (as Dr. Watson has observed) a connecting link between gout and rheu matism, and partakes of the characters of both.
The only known exciting cause of acute rheumatism is exposure to cold, and espe oially to cold combined with moisture, and hence the greater prevalence of this disease among tile poor and ill-clad. Sleeping in damp sheets or upon the damp ground, the wearing of wet clothes, and sitting in a cold damp room, especially if the sitter was previously warm from exercise, are examples of the kind of exposure which is apt to be by this disease. The excreting power of the skin being checked by the action of cold, certain effete matters which should be eliminated in the form of perspiration, are retained, and accumulate in the blood, which thus becomes poisoned. This blood poisoning is not., however, a universal sequence to exposure to the cold. It only occurs when there is a special predisposition to this disease, or, as it is termed, a rheumatic -diathesis or constitution, and the diathesis may be so strongly developed as to occasion an attack of acute rheumatism, independently of exposure to any apparent exciting cause. Men are more subject to the disease than women, but this probably arises from their greater exposure to atmospheric changes from the nature of their occupations. The predisposition is certainly affected by age; children under ten years, and adults over 60, being seldom attacked, while the disease is most prevalent between the age of 15 and 40. Persons once affected become more liable to the complaint than they previously were. Dr. Fuller believes, from his observations made in St. George's hospital, that the disease is sometimes hereditary; whether this be the case or not, there can be no i)ossible doubt that the predisposition is very apt to exist in members of the same family. The exact nature of the poison is unknown. The late Dr. Trout regarded lactic acid as the actual materies morbi, and certain experiments recently made by Dr. Richardson tend to confirm this view.