inflammation of the fibrous tissues is a common affliction in early life. In childhood, indeed, there appears to be a peculiar tendency to rheumatism ; and in young people the disease may assume very special characters. The joints are ,generally affected, but other fibrous structures suffer as well. 'More often than in the adult the articular inflammation is absent, and not infrequently it is very partial and takes an insignificant share in the illness.
The great importance of rheumatism in children is due to the inflam mation in and around the heart, of which it is so frequently the cause: The large majority of cases of heart disease are the consequence of rheu matic occurring in early life. But besides the heart other fibrous structures may be attacked. The pleura may be affected ; the meninges of the brain and spinal cord may suffer ; and sometimes fibrous tissues in other situations may be implicated, as will be afterwards de scribed.
Acute rheumatism is said to be tmcommon under five years of age ; but the accuracy of this assertion is open to question. Infants and young children may not suffer from much articular swelling and pain, but it is a common experience to detect a cardiac murmur at the mitral orifice in a young child, and to discover, on inquiry, that the patient had some weeks or months previously been feverish, with a little stiffness and tenderness of one or more joints, symptoms amply sufficient to establish the rheumatic origin of the cardiac disease.
principal cause of rheumatism is exposure to cold, or to cold and damp. In young children and infants a very slight impression of cold may suffice to set up the disease. Thus, I have known a young child exposed to draught from the nursery door, while being dried, after a bath, before the fire, suffer shortly afterwards from stiffness and pain in the knees and endocarditis. Sudden changes of temperature are favourable to the production of rheumatism. In England the disease is much more rife during the spring and the autumn, when the evenings suddenly turn chilly and damp, than in the winter months when the temperature is more uni form.
Many influences favour the action of cold and moisture in producing rheumatism. Family tendency will do this. A large proportion of rheu matic children come of rheumatic parents. Again, previous illness of the same kind predisposes to fresh attacks. When a child has once suffered from rheumatism, he is very likely to suffer from it a second time. The state of the health at the time of the exposure exerts some influence. The existence of catarrh of any mucous membrane renders the patient very sensible to chills, and makes exposure very dangerous to a child of rheu matic tendencies. Lastly, scarlatina predisposes with peculiar force to rheumatism or to a disease indistinguishable from it.
Norbzd Anatomy. — When a joint becomes the seat of rheumatic in flammation, there is reddening of the synovial membrane lining the joint, the synovial fluid is increased in quantity and often milky, and there is some effUsion of fluid into the surrounding tissues. Suppuration in the joint is very rare.
In pericarditis the pericardium is reddened and softened, exudation of lymph occurs on the serous surface, and fluid is effused into the cavity. The serous fluid and the more solid lymph vary greatly in amount, and either may be in excess. The quantity of fluid thrown out is sometimes enormous. It may be clear or opalescent, or tinted red from blood. Sometimes, as in pleurisy, although far less frequently than in that disease, the fluid is purulent. The layer of lymph, also, may reach a great thick ness. It may be smooth, or pitted with holes like a honeycomb, or ribbed like the sea-sand. Sometimes the visceral and parietal layers are united by soft thick bands of lymph. If the inflammatory process iu the pericar dium is severe, the heart substance towards the surface is generally sof tened to a certain extent and weakened. If much lymph has been thrown out, more or less complete adhesion is likely to take place, after absorp tion of the fluid, between the opposed surfaces of the serous membrane.