ARTICLE VIII.

SMALL-POX: ITS DIAGNOSIS.

IN

BY JOHN T. BULLARD, M.D.

OF NEW BEDFORD.

many cases the diagnosis of small-pox can be made at once from the eruption itself and without hesitation, while in others the decision can be made with certainty, but only after a few days of observation. It is in the milder and modified forms of small-pox, however, that considerable difficulty or even impossibility in making a correct diagnosis occurs, and it is through these patients that the disease is usually transmitted to a large number of others. It becomes often a most difficult matter for a health officer, called in perhaps for the first time in the stage of desquamation, to decide from the imperfect history he is usually able to glean, whether the case has been one of small-pox, should be immediately removed, a large number of people quarantined, or whether the malady has been a varicella and no precautions are demanded.

It should be borne in mind that several facts beside the eruption are of value, and should receive consideration in each case.

The first question that should be asked is: Has the patient in any way been exposed to small-pox? In epidemics where exposures can be easily traced, we are enabled to de

cide very early in the disease what we have to deal with, and are justified in sending our patients early into quarantine, thereby lessening the danger to others. While the history of exposure can not, many times, be ascertained, it is well to remember that no case of small-pox originates de novo, and careful questioning may reveal some friend or neighbor who has had a recent eruption, and investigation of the latter case may throw considerable light upon the one under consideration.

Secondly. Has the patient been vaccinated, and if so how recently? In an epidemic of about 175 cases in New Bedford in 1900, nearly all occurring in French-Canadians, 95% of the victims were unvaccinated, and in many households the unvaccinated were affected and those vaccinated escaped. A pertinent question also, is, "Has the patient ever had chicken-pox?" Age also has some diagnostic value. While chicken-pox is essentially a disease of childhood, small-pox attacks all ages equally.

Next come the constitutional disturbances which occur before the eruption. Notice the sudden onset, the rise in temperature, rigors or chills, often nausea and vomiting, severe frontal headache, and backache,-in fact, the usual symptoms of any acute febrile disorder. All writers lay especial stress on the severe and peculiar backache corresponding to the lower dorsal, lumbar and sacral vetebræ, and some state that it is hardly ever absent, and is almost "pathognomic."

Especial care was taken by the writer and his associates on the Health Board to investigate this symptom during the epidemic above referred to, with the result that they found it not at all a prominent symptom, being absent entirely in many cases, and in others complained of as merely a dull aching low down in the back. Severe frontal headache was much more prominent and frequent. The consensus of opinion, however, points to backache as of consider

able diagnostic value. In mild cases these prodromal symptoms may be present either with the same intensity as in the severe ones, or they may be greatly modified and not pass beyond a period of feverishness and malaise.

If a diagnosis is attempted at this stage, influenza must be remembered. The symptoms are very similar, and many errors have been made, by both physician and patient thinking that the case was one of grippe, the patient being discharged before the appearance of the eruption.

During the stage of invasion, usually on the second day, in a small proportion of cases a so-called initial rash of two different forms may appear, either erythematous as a scarlatina or blotchy as in measles, and may lead to an error in diagnosis; although sometimes general, as a rule they affect only the lower part of the abdomen and inner surfaces of the thighs, usually are transient, fading away in twelve to twenty-four hours. Here the diagnosis may be made of scarlet fever. The longer duration and the severity of the premonitory symptoms, the unusual location of the rash, the duller red color of the erythema and the absence of severe angina and enlarged cervical glands should enable the physician to at least lean toward sinall-pox. Erysipelas should be borne in mind, but its method of spreading and its peculiar glazed appearance do not offer serious difficulty in recognition.

In the papular form of initial rash, we have a certain similarity to measles. The catarrhal symptoms of measles are not prominent in small-pox.

These prodromal rashes last only a few hours, and are not a serious obstacle to diagnosis.

On

The true eruption itself must now be considered. the fourth day macules appear on the forehead, around the roots of the hair, and about the mouth, nose and eyes, the temperature drops to normal, and in mild cases may remain so until the end of the disease. I know of no other

disease where the temperature curve acts like this. These macules become papules and indurated, and by the next day present to the touch a shotty feeling, due to the anatomical arrangement in the skin. These lesions by the next day or two appear on the trunk and extremities, the feet being the last part affected.

Then follow the vesicles, at first minute and then larger, then umbilication, and about the sixth day of the eruption pustules, suppuration, fever, and lastly dessication, taking place first in the centre of the pustule and finally the transformation into a dark brown or blackish crust.

This eruption may be discrete or confluent. It may also be hæmorrhagic when ecchymoses appear in the skin and conjunctivæ in the prodromal stages and into the lesions themselves afterwards.

These are the so-called "text-book cases" and can be quickly passed over as the diagnosis is readily made, and we will consider the milder cases and with what diseases they may be confounded.

In so-called varioloid, called also modified small-pox and pseudo small-pox, occurring especially in the vaccinated, and in certain recent epidemics, the errors in diagnosis are frequent, and the fact that in many cases the services of a physician are not called for, does much to favor the spread of the disease. The erythematous initial eruption is mentioned as being more often met with in the milder epidemics, but in our experience it was seldom met with, or if present was of so transient a nature that it escaped observation. To add to the difficulty of diagnosis the eruption often is abortive, going no further than the papular stage; or it may progress to a small vesicle which soon shrinks; or may become sero-purulent, stop there and dessicate. We had two cases that were surely small-pox, in which after some severe constitutional symptoms the eruption never developed at all.

There are many cases where there is no secondary fever, and the patient is convalescent after the appearance of the eruption, which may be extremely scanty.

I had the opportunity to see one case recently where with moderate prodromal symptoms the rash was limited to a few lesions on the face, perhaps half a dozen, only two of which became pustular. A few papules appeared on the chest on the following day. These lesions quickly dried up, but there was considerable induration, and knowing the exposure and history of the case there was no doubt that the disease was small-pox, occurring in a man who had been successfully vaccinated some eight years previously. Here, without the history, the diagnosis would have been extremely difficult.

What eruptions are liable to be confounded with smallpox?

PUSTULAR ECZEMA may at first deceive the practitioner. The history of the case, including absence of constitutional symptoms, the absence of throat symptoms, and the distribution of the rash, should enable the physician to make a diagnosis. There is also a lack of well-defined progressiveness to the lesions. The vesicles and pustules are small and arranged on an inflamed base which is larger than the papule of small-pox.

SYPHILIS. The similarity is often so close as to deceive even the most experienced. There is an identity of anatomical forms and also of evolution through the stages of papule, vesicle and pustule. Hutchinson says: "The simulation of the variolus eruption by syphilis is the most marked example of syphilitic imitation. The papules are elevated, shotty to the finger, have depressed centres, affect the same regions as small-pox, and resemble it so absolutely that nothing but the history of the case can help the surgeon to a correct opinion."