2. Nephritis due to other Infections and Intoxications, and the so-called Primary Nephritis The number of ettses of nephritis front the above causes is not as large as those due to gastro-intestinal diseases. It is unusual to meet with scarlatinal nephritis in early infancy, because children of this age are comparatively inimune to searlet fever. We find this affection more often in connection with other exanthemata, such as varicella, and as a complication of pneumonia. Inflammations of the kidneys are also seen resulting from meningitis, erysipelas, angina, pyamia, tetanus neonatorum, impetigo eontagiosa, aphthous stomatitis, and general ized eczema (one of the most severe eases of nephritis which has come under my observation in an infant appeared in connection with a strer.
tococcus catarrh). fleubner dwells upon the frequency of nephritis in infantile scurvy. The nephritis is usually Inemorrhagic in character, and its cure is effected along with the casual condition by suitable dietetic treatment. Infants are more easily attacked by nephritis than are adults in consequence of the external use of toxic substances, such as iodine, tar, styrax, etc., and such application ought therefore to be made only when the condition of the urine can be watched, and the presence of albumin and casts promptly dctected.
Besides the forms of nephritis whose etiology is pretty definite, in spite of the fact that neither their clinical nor their pathological history has been perfectly studied, there are others which appear without any definite preceding cause. These are called acute "primary" nephritis. The treatment of these cases corresponds to that which has been ad vised in the other forms which have already been discussed.
3. Nephritis dtte to Congenital Syphilis It has long been known that syphilis in adults at any stage may lead to the development of the large white kidney, with cederna and abundant excretion of albumin, and under certain conditions also to the contracted kidney.
The nephritis of hereditary syphilis in infancy has been studied carefully only in the last ten years so as to complete our previous knowl edge by accurate clinical observations. Among the writers who have earned special recognition by their work in this connection we may mention Cassel, Hecker, Hochsinger, Karvonen, v. Strobe, and St8rk.
Cassel examined 31 babies with hereditary syphilis between two weeks and seven months of age, and in six of these he found albumin and casts in the urine. Hecker in twelve cases found the urine free from
albumin in but two of the children. In all the others he established from the uranalysis the diagnosis of distinct alteration in the kidneys. There were six cases with marked parenchymatous nephritis, charac terized by abundant albumin and casts while in four there were traces of albumin. Karvonen found a pathological change in the urine but once in six syphilitic infants, of whom two were premature. We have not as yet sufficient material to draw any far-reaching conclusions, but at any rate it is striking that the majority of examiners found clinical evidences of nephritis in only a small percentage of their cases, while they all lay stress upon the pathological histological alterations the kidneys of both mature and premature syphilitic infants.
The pathological changes in the excretory apparatus of the kidneys consist in more or less serious parenchymatous degeneration. The epithelium of the tubuli contorti as well as of the glomeruli may become affected. Cystic degeneration of the glomcruli and the urinary ducts is often found. The damage done by the syphilitic virus is character ized by pathological alterations in the connective tissue and the vas cular apparatus, especially peri-adventitial deposits. To this there may be added deficient development of the glonwruli and of the tubuli uriniferi, so that their number may be considerably less than in the normal kidneys.
The nephritis of hereditary syphilis bears no relation to the severity of the fundamental disease, and the diagnosis is therefore correspond ingly difficult, because, on the one hand the uranalysis may be abso lutely negative, notwithstanding the fact that the pathological altera tions in the kidneys may be well marked, and, on the other hand, when the urinary reaction is positive, it is by no means easy to exclude other etiological factors, especially the influence of mercury in cases which have received specific treatment. Conspicuously large quantities of albumin such as are seen in the syphilitic nephritis of adults, do not. appear to be the rule in that of infants; renal hawnorrhage and oedema have been but seldom observed (Finkelstein); and lira:tiff(' symptoms in this affection have not been observed.