DISEASES OF THE PERICARDIUM (a) PERICARDITIS. INFLANIMATION OF THE PERICARDIA:NI Etiology and Occurrence.—Although circumscribed areas of cloudiness anri thickening of the pericardium in the region of the apex and the points of entrance of the venni cavre are frequently found at autopsy in thc hearts of children, pericarditis in childhood is in general less common than in the later years of life, doubtless because of the very much greater rarity of rheumatisitt in childhood. Therefore the recognition of pericarditis in the living child offers greater difficulties than in adults, and frequently enough, especially in infancy, it appears as a surprise at autopsy. According to the statistics of Cnopf and Weill pericarditis is only one half as frequent between the second and fif teent h years as in later periods of life, and is most frequent in childhood from the seventh to the tenth year. Pericarditis is most rare from the second to the seventh year of age, and somewhat more frequent in the first year, on account of the pytemic infections which enter more into the question etiologically at that time of Efe.
Cnopf found pericarditis seven times (5.38 per cent.) out of 130 autopsies performed upon children. The most frequent causes of the occurrence of pericarditis in children are the acute infections, especially the exanthematou.s diseases, scarlet fever, measles, varicella and ery sipelas; it may also result from inflammation of the neighboring organs (lungs, pleura, tried:ant:nal glands, thymus gland, cesophagus and bones of the chest wall). Acute and chronic nephritis are also frequently associated with pericarditis, not to mention articular rheumatism, which enters less etiologically into the question of pericarditis in early childhood, because it occurs more rarely at this period than in later life. So, too, the infection of the inflammatory diseases of the abdominal cavity sometimes spreads directly to the pericardium in children.
Banti found, in two cases of pericarditis associated with pneumonia, Frankel's diplococcus in one and in the other the staphylococcus aureus and albus. In a child operated upon by Korte the pericardial exudate contained staphylocci, streptococci a.nd short bacilli. In another case examined by Banti, pericarditis with nephritis, the exudate was sterile. Pneurnococcus infection was primary in A. CRSC described by Coutts, without pneumonia.
The occurrence of an idiopathic pericarditis is questionable. Un
noticed rheumatism or traumatism play a part in cases in which the etiology is obscure. Naturally tuberculosis is also an etiologic factor in the occurrence of pericarditis in childhood and may spread espe cially easily from diseased mediastinal glands.
It is a peculiarity of childhood that pericarditis in the earliest periods of life depends chiefly upon py:Prnic infection; in middle child flood, mainly upon the spread of inflammatory processes; and in later childhood, generally upon rheumatic, and also choreic foundation. Cor responding to this, the exudate in early life is usually purulent, in middle childhood generally serofibrinous, and in later childhood almost always purely fibrinous.
An especial peculiarity of childhood is the exceptionally frequent combination of pericarditis with endocarditis, which occurs when the condition is due to rheumatism and chorea. Weill and Ilenoch lay stress upon the possibility, in childhood especially, of the appearance of ail endopericarditis before the general symptoms of rheumatism. Not rarely to a condition which at the beginning only affected the endo cardium, pericarditis may later be added, with equal frequency whether the cardiac disease was at first acquired or congenital.
Pathologic there aro only slight diff erences between pericarditis in children and adults. Perhaps purulent exudates are relatively more frequent in young children than later. Pericarditis at an early age more frequently leads to obliteration of the pericardium. More rarely does the process go on to deep-seated disease of the cardiac muscle, such as purulent infiltration and progressive fatty degeneration. The very intense injection of the blood vessels and the rapid appearance of abundant liquid effusion are characteristic of acute pericarditis in childhood. Purulent pericardial effusions are as a rule metastatic processes, the result of puerperal sepsis or osteo myelitis, or they occur from the spread of purulent inflammation of the lungs, pleura or mediastinal glands. I-hemorrhagic effusions are found in childhood in \Verlhors disease, infantile scurvy (Seidlitz and Kyber) and in tuberculosis. Besides, as in adults, acute and chronic, dry and exudative pericarditis must be differentiated. Dry pericarditis is com monly found as an accessory condition with endocarditis in children.