Nephritis does not appear to have any special predilection for the cases which are severe from the beginning. lleubner, out of his rieh experience, confirms the fact that the abortive eases, with slig,ht constitu tional disturbance, and in which the exanthem was almost overlooked, are at least as often followed by the renal disease as are the severe types, and we are as little able to avoid the complication by any therapeutic measures, as we are able to infer the probable future kidney complica tion by any symptom occurring in the beginning of the disease. The influence of cold, frequently assigned as an indirect cause, may be denied, since nephritis scarlatinosa probably affects those whose nurs ing was above criticism as it does patients who go through the scarla tina' attack under the most unfavorable hygienic conditions, with deficient nutrition, and without any proper regulation of the diet. We may consider that the statement made by some writers has been re futed, that in eases in which nephritis appears the disorder was present from the beginning, but was unrecognized because its symptoms were masked by those of the general disease. On the contrary, the exami nations of Thomas and Heubner have certainly proved that after the stage of albuminuria the urine will return for a time to the normal before a nephritis scarlatinosa suddenly appears. Furthermore the altera tions in the kidneys are minimal in persons who (lie in the first week of scarlet fever. The observations of Rosenstein and Lenz, to the effect that scarlatina] nephritis occurs most frequently during the stage of desquamation at the end of the third week, have been confirmed. Among 36 eases which Heubner followed from the onset, the nephritis began 17 times between the twelfth and fifteenth days; 10 thnes between the seventeenth and nineteenth days. The renal inflammation appears therefore at a time when the rest of the disease seems to be over. In the widest sense of the word it is a late effect of the infection. Rookie'. says that perhaps a special organic suseeptibility or lack of resistance, influences the appearance of the renal inflammation. The new experi ments in etiology have suffieiently demonstrated.the occurrence of such a relation between quite isolated cell groups and certain poisons, espe cially poisons of the group of parasitic toxins or products of dissolution. The family disposition to scarlatina' nephritis which has often been observed, is of interest. It is certainly impossible to determine whether the conception of the kidneys as the point of least resistence is well founded.
Symptomatology.—The appearance of nephritis is often shown by no other symptom than alterations in the urine, which are generally characteristic, and which should therefore be promptly investigated.
The first albumin may be shown in a light, almost clear urine (Burger). The sediment in these cases is scanty, and consists only of isolated casts, red and white blood corpuscles, and epithelium. The corollary of this onset is the form in which casts are secreted without albumin, whieh shows the importance of both chemical and microscopic examination at the time when we fear the appearanee of a renal compli cation. Gradually after some days the urine may take on its character istic appearance and then the attention of even the layman may be attracted to it. This may be present from the beginning. The urine is
dark, turbid, and of varying shades of reddish brown. The quantity diminishes in proportion to the depth of the color, and the specific gravity is at first increased (1.025-1.040), but later on it falls to 1.015 and lower. The albumin which is always present at this stage may be so plentiful that the urine when boiled coagulates in the tube in a solid mass (1 per cent. and more). The coagulated albumin is colored a dirty brown by the adherent blood-pigment. Above all the sediment is char acterized by tlw conspicuously large number of red blood corpuscles, which are a sign of the hannorrhagic character of the scarlatinal neph ritis. Besides luemoglobin containing blood corpuscles, extraordinarily small ones arc to be seen in addition to the normal sized ones. The presence in thc sediment in the form of a brown detritus, of fragments of blood coloring matter, is an indication of the dissolution of the red corpuscles, which may take place in the kidneys themselves. Casts may be present in great num bers—hyaline of every size and form. blood casts. and epithe lial casts. Renal epithelium, leucocytes and fatty cells are all far lcs.s numerous than the red blood corpuscles.
The daily examination of the urine for albumin and formed elements is as impor tant for the diagnosis of the be ginning of the renal disease as is the continual estimation of the daily quantity. For neither the daily quantity of urine, nor the percentage of albumin nor the quality of the sediment, inform us of the approaching danger. The less the quantity, the greater, as a rule, the danger of the development of urtemic symptoms.
V. Pirquet considers that the weight curve is of diagnostic value in the beginning of acute nephritis, because the retention of water occurs in most eases earlier than the albuminuria. According to him, the renal inflammation generally goes along with an increase in the weight which results from a retention of water, and this increase shows a typical curve on the weight chart.. He believes this increase in weight of greater prognostic importance than the detection of albumin.
As to the other clinical symptoms the onset may be quite different. In some cases there may be scarcely any systemic disturbance; in others there may be present a distinct feeling of sickncs.s, with restless sleep, headache, vomiting, and anorexia. The pulse and temperature may be elevated, the latter as high as 40-41° C. (104-105.8' F.), with chill and subsequent sweating, ancl the fever may continue for days or even for weeks. Slow pulse bas been observed by Heuhner despite the temper ature. Pallor and swelling of the face are in most cases a conspicuous initial symptom. The pallor is the result of an abnormal distribu tion of the blood, and perhaps also to the decrease in the percentage of lunmoglobin at the beginning and during the course of the nephritis, which has been studied more exactly by Widowitz. According to Heubner an attentive examination at the beginning will almost, always reveal mdematous swelling of the cutaneous tissue over the sternum and the anterior surface of the tibia.* A painful swelling of thc bronchial lymph-nodes appearing simultaneously with the onset of the nephritis, is often conspicuous.