Enlargement of the spleen is the second most important clinical symptom of malarial infection. In regard to its frequency, writers are by no means unanimous. While some have scarcely ever missed it (for instance, Laveran), others assert that they have often seen cases without it, for instance, Plehn. Even more those thoroughly grounded students of malaria , Kelsch and Kiener, writet that in simple intermittent fever "aucune tumefaction de la rate ni du foie n'est appreciable." These last further afhrm that they have seldom observed enlargement of the spleen on the first occurrence of a remittent, in contrast to the remittent and adynamic typhoid malaria , in which, from the beginning, a painful tumor of the spleen is usually evident.
Among 132 cases of malaria of different types-cachexias omitted -I have missed only once the tumor of the spleen, and this in a case of severe typhoid malaria with small parasites. Fifteen times the spleen was enlarged to percussion; 116 times it was palpable. It was regarded as enlarged by percussion only when the splenic dulness reached or overstepped the anterior axillary line.
Among my cases there were many primary infections of short duration, as well as numerous relapses. In almost all cases the malaria was verified by the blood examination. This difference in results cannot be fully explained. Omitting errors in diagnosis, which are frequent in malarial as well as non malarial regions, when the diagnosis is made without a blood examination and with careless examinations of the spleen, there is left little else to which we can attribute this astounding variance. Individual circumstances- like thickening of the capsule of the spleen, which prevents enlargement of the organ-are probably no more frequent than we see them here. A difference in the character of the virus only remains, though this assumption, in the light of the similarity of other symptoms, is not very probable.
From my own experience I can only say that the enlargement of the spleen is a constant symptom in all forms of malarial infection, being in the minority of cases-about 12 per cent.-evident only to percussion; in the majority-about 88 per cent.-palpable.
The longer the disease lasts and the more frequent the infection, the larger and harder becomes the tumor. In a case of recent infection the spleen is soft, has a sharp margin, and extends beyond the arch of the ribs on deep inspiration only one to two finger breadths. It is a fact, easily confirmed in recent infections, that the spleen increases in size with the paroxysm and becomes smaller during the intervals.
According to Griesinger, a whizzing murmur, similar to the placental rale, is sometimes audible over the tumor.
The most marked tumors of the spleen are found in inhabitants of severe malarial regions, who year out and year in are exposed to the infection, and are, as a consequence, in a condition of malarial cachexia.
After one not too prolonged infection, the enlargement may decrease, so as to leave the organ normal, yet this is not constant, for we frequently see the splenic tumor, even though somewhat reduced in size, continue throughout life. This "ague cake" is more likely to remain the more frequent the infection.
In recent infections the spleen is not rarely the seat of spontaneous pain of a pricking character, which increases on movement of the diaphragm and recalls the pain of pleurisy. In these cases palpation of the organ is very painful. At other times the pain occurs only on palpation.
This pain is usually due to stretching of the capsule, yet it may be due to inflammation of the covering of the spleen; in other words, perisplenitis. The old "ague cakes"-omitting complications-are usually insensitive.
The tension of the spleen may be so great as to produce rupture of the organ. This occurs especially after trauma and causes almost immediate death on account of the rapid hemorrhage.
We may call attention here to pains in the bones, which are a frequent cause of complaint-in fact, often the only complaint. In these cases I have not infrequently found percussion of the tibia or of the sternum painful. It is, therefore, possible that the pain in the limbs complained of by patients is attributable, at least in part, to the change in the bone marrow which has been found in malaria . This pain on percussion is by no means constant.
In relation to the remainder of the lymphatic apparatus, we refer the reader to the Special Part.