Rupture of the spleen occurs occasionally, and is usually attended with sudden pain, collapse, and speedy death. Murchison refers to two examples recorded by Zuelzer and one by Hudson; Petersen reports fifteen cases, in seven of which sudden rupture occurred with speedy death, while in the other eight the rupture followed local softening from infarction, and resulted in death in a few days from purulent peritonitis.
In one of our cases, where death occurred on the sixteenth day, apparently from double pneumonia and heart-clot, it was found that there was a rupture in the enlarged spleen near its upper end, recent plastic peritonitis in the region of the spleen, and a moderate amount of bloody pulpy fluid throughout the peritoneal cavity.
As we have seen, disturbances within the respiratory tract occur with very different frequency in different epidemics. In many they are rare, while in 1870 we noticed cough and other evidences of respiratory trouble in no less than 90 out of 200 cases.
Severe catarrhal laryngitis is a rare and dangerous complication. It did not occur in our cases, but both Begbie and Paterson report cases of it which required tracheotomy, and Wyss and Bock met with ulcerative laryngitis with perichondritis.
Bronchitis of moderate severity, although rare in many epidemics, occurs so frequently in others, as in Philadelphia in 1870, as to rank as a symptom of the disease.
Pneumonia is one of the most fatal complications. The results of our own observations agree with the statements of Jenner and of Carter, that it is the next most common lesion after enlargement of the liver and spleen. On the other hand, Murchison noted it only in 4 or 5 out of 600 cases. It occurred in at least 11 of our cases, 8 of which were fatal; and unquestionably less extensive inflammation was present in other cases which recovered, in view of the marked respiratory disturbances frequently present. Both lungs were involved in 4 cases; of the remainder, the right and left were about equally divided. Out of 23 autopsies, the lesions of pneumonia were found 8 times. The lower lobes were affected in every case. The form of this disease was croupous in 9 cases; in 1 it was that of metastatic suppuration, and in 1 it was more properly described as splenification. The amount of plastic pleurisy associated with it was usually great, and in one case there was also severe pericarditis. In another case the disease advanced to the stage of gangrene of a circumscribed area of the pleura and of the superficial layer of the lung. In only one instance was albuminuria present. In two cases the pneumonia occurred so late in the course of the disease that it might be regarded as a sequel. Death occurred in one of these on the thirtieth day, and in the other (that in which gangrene ensued) it ran a subacute course, and death did not take place until the fortieth day. In the other cases the disease began at the close of the initial paroxysm, during the intermission, or early in the relapse. As would be expected, the sympathetic fever due to this complication modified and obscured the characteristic course of the specific pyrexia.
This rare termination in gangrene has been noted by other observers; in all five or six times. Parry met with a truly remarkable case of double pneumonia, followed by gangrene, and yet resulting in recovery. Jaundice is apt to attend cases of relapsing fever which are complicated with pneumonia.
Pleurisy is an almost constant accompaniment of pneumonia, and frequently occurs in marked degree. It may also be present in cases of severe splenic inflammation. In all probability, localized plastic pleurisy is not infrequent, and may cause some of the severe thoracic pains so frequently present.
Metastatic abscesses of the lung occur occasionally as a result of the profound toxæmia, and are apparently preceded by patches of infarction, which soften in the centre, as in the usual development of pyæmic abscesses. This condition was found in one of our cases in conjunction with suppurative parotitis. It has been included among the instances of pneumonia.
Acute miliary tuberculosis, involving chiefly the lungs and intestinal canal, occurred as a sequel in one case under our observation, and phthisis has been found to follow by other observers (Carter). It is to be expected that if the patient did not so quickly pass from under observation it would be found that an affection so gravely complicating nutrition as does relapsing fever is frequently followed by serious organic disease.