CHAPTER VIII.

DIAGNOSIS.

A STRONGLY-MARKED case of fatal or grave yellow fever can hardly be confounded with any other disease. An initiatory chill of moderate duration and severity, immediately followed by intense pain in the head, back, and limbs; redness and suffusion of the eyes; moderate excitement of the circulation; moderate heat of the surface; loss of appetite; thirst; and a white tongue, with red tip and edges; these febrile symptoms, marking the first stage of the disease continuing for one day or so, and then associated with, or followed by, epigastric pain and distress; nausea and vomiting; restlessness and anxiety, often more or less paroxysmal; and in from three to five or six days after the attack, by yellowness of the eyes and skin; vomiting of a matter resembling coffee-grounds held in a darkcolored fluid;' very dark or black stools; coldness of the extremities; increasing and excessive restlessness, with occasional hiccough; hemorrhages from different parts of the body, and suppression of urine-the mind in many instances remaining clear to the end, and death taking place in from five to seven or eight days from the attack; these phenomena, thus combined and thus following each other, constitute a disease which it seems impossible to mistake for any other. Asiatic cholera, puerperal peritonitis, and distinct smallpox are not more clearly and broadly marked, by their peculiar and characteristic physiognomy, than the yellow fever, occurring in this form; and had we not abundant evidence of the extent to which even clear heads and sound judgments may be mystified and perverted by hypothetical and à priori systems of medical philosophy,

[It may be important to the young practitioner to state that black vomit is by no means a constant symptom, even in the fatal cases of yellow fever. This will be clearly seen by a reference to Sec. 2, Chap. III, where the causes of death are considered. M. Louis states that in fourteen fatal cases, whose histories were preserved, though thirteen vomited, "the color of the vomit was brown or black in eight." Some observers have met with it in only about half their fatal cases.]

it would seem incredible that this disease should have been regarded by many observers as a variety merely of ordinary remittent fever. A single remark should be made in relation to the state of the organs after death, as an element in the diagnosis of fatal cases. The only phenomena peculiar to the disease are the change in the color of the liver, and the presence of the matter of black vomit in the stomach and intestines. In cases where either or both of these are found, we have an additional and very conclusive evidence of the nature of the disease. It is very important, however, to add, that the absence of both these conditions is not to be taken as positive proof of the non-existence of the disease, in any given case, since it is quite certain that, in a considerable number of instances, death takes place without any formation of the matter of black vomit; and there is also some reason to believe that the change in the color of the liver is not a constant occurrence.

The diagnosis of the more moderate grades of the disease, including even the severer forms which terminate in recovery, may be somewhat less positive, perhaps, than that of the foregoing cases; but it cannot often be attended with any difficulty or doubt. It is very true that some of the most striking features of the disease are often or usually wanting in these cases; there is frequently no yellowness of the skin, but slight restlessness, and epigastric distress, or none; and no black vomit; but the violence of the local pains, the early suffusion of the eyes, and the rapidity with which the disease passes from the second stage to convalescence and recovery, will be quite sufficient to supply their places, and to remove all uncertainty.

The diagnosis of the milder and slighter form of yellow fever must often be more or less qualified and doubtful; and it will depend in part upon the circumstances under which the disease occurs. Thus, if a considerable number of persons in the same family or neighborhood are attacked, during the prevalence of yellow fever, with pains in the head, back, and limbs, moderate febrile excitement and redness of the eyes-especially if these persons are mostly children, negroes, or individuals more or less acclimated, there can be but little doubt, if any, in regard to the character of the disease. Mr. Pym says: "The most characteristic symptom of the disease is the peculiar pain in the forehead and eyeballs, with the drunken appearance of the eye."1

1 Burnett, p. 209.

Again, the diagnosis may sometimes be rendered somewhat doubtful, by the presence of the remittent or periodical element in the disease. Dr. Lewis, of Mobile, has called the attention of physicians particularly to these mixed cases, and to the difficulty which often attends their diagnosis. It does not appear, however, that the peculiar features of yellow fever are much modified, or the usual course of the disease much interfered with, by the addition of this periodical or remittent character. Dr. Lewis, in his description of the Mobile epidemic of 1843, says: "Some physicians complained that they were always taken by surprise in these cases; that there was no symptom which could lead them to suppose that they were cases of yellow fever; hence they viewed them as simple intermittents, running, under atmospheric influence, into black vomit. I was deceived in three cases only; two of which were under my treatment, and the other I saw by accident. After this, I was able to make a proper diagnosis, usually on the second or third day. During the apyrexia, there were the peculiar pulse and uneasiness belonging to the calm or passive stage of yellow fever; and in the absence of these, the eye or skin was sometimes indicative of the character of the disease." [Yet Dr. Fenner, of New Orleans, holds different language: "The truth is," according to him, "yellow fever is so closely allied to various remittent and intermittent fevers, that no uniform and reliable distinction can be drawn between them, in the early stages. Even in such an epidemic as this (1853), thousands of cases occur which no one would have thought of calling yellow fever, if it had not been generally known that many of the same character and appearance had terminated in black vomit. I have not yet found a man who could always say correctly, whether a case, examined per se, was yellow fever or not."]

Finally, cases will unquestionably now and then occur, so indistinctly and obscurely marked, or so mixed up with other morbid phenomena so anomalous and irregular in their symptomatological manifestations-as to escape the scrutiny of the closest and most experienced watcher. What is true of most other diseases is true also of this; and here, as elsewhere in the domain of diagnosis, although, as a general rule, and in an immense majority of cases, our conclusions may be absolute and positive, we are sometimes held to the necessity of being satisfied with such as are only quali fied and approximative.

'N. O. Med. Journ., vol. i. p. 292.

CHAPTER IX.

THEORY.

THE theory of yellow fever, like that of the preceding diseases, can consist, at present, only of a few probable approximations. We may pretty safely say, in the first place, that it is not a simple gastritis. Notwithstanding the general presence and the grave character of the lesions of the gastric mucous surface in fatal cases, and the corresponding constancy and gravity of the gastric symp. toms, it seems to me that a rational interpretation of all the phenomena of the disease leads inevitably to the conclusion above stated. The order of succession, in the phenomena of yellow fever, is not such as occurs in simple acute gastritis. The gastric symptoms do not accompany the general febrile excitement; the latter precedes the former. If the high fever of the first period is dependent upon gastritis, there should be at the same time some local symptoms of this latter. The first stage of the disease is not accompanied by any signs of gastric inflammation; and in mild cases, and not unfrequently also even in pretty severe cases which terminate in recovery, there are no such signs during any period of the disease. This could not be so generally the case, if the disease consists primarily and essentially in an inflammation of the mucous membrane of the stomach. The gastritis, there is every reason to believe, is a secondary lesion like that of Peyer's glands in typhoid fever, one of the results, immediate or remote, of the unknown poison of the disease. This interpretation is in no way inconsistent with the importance which I am disposed to attach to the local disease. This is probably one of the principal causes of danger and death.

Of the peculiar lesion of the liver, I have already sufficiently spoken. We know too little of its nature and relations, to justify us in attempting to estimate its importance, or to fix its position, in the theory of the disease to which it belongs.

It is very probable that a most important element in the patho

logy of yellow fever is to be found in the alteration of the blood which has already been described. The etiological poison of the disease, received into the system, works a morbid change of some sort in this fluid, the immediate effects of which are manifested in the first stage of the disease; in mild and moderate cases, these effects are carried no further; but in grave and fatal cases there are superadded to the contamination of the blood, certain consecutive local lesions, especially of the liver, and the mucous membrane of the stomach, [and we must now add, functional change in the kidneys.]