From what has already been said, it will be anticipated that the variations of the temperature in relapsing fever constitute the most peculiar and characteristic feature of that disease. A careful study of the accompanying charts will convey a more accurate impression than can be given by any description. The temperature begins to rise before the chill is fully developed, and when there is no initial chill the patient may be found within a few hours of the appearance of giddiness and headache with a temperature of 102.5° to 103.5°. Before twenty-four hours have passed it has risen to from 104° to 106°. During the paroxysm the febrile movement is continued, presenting merely a diurnal variation of one to two degrees, sometimes attended with sweating and partial relief of distressing symptoms, the minimum being observed at different hours in different cases, or even in the same case, though more frequently it occurs in the morning.

In a case reported by Parry a chill recurred at the same morning hour on three successive days. Wyss and Bock report some unusual cases in which a brief intermission occurred, with a fall of pulse and temperature to the normal, most frequently on the day before the real termination of the paroxysm. The highest temperature varies from 104.5° to 108.75°; in our cases the highest observed was 107.5°. This occurs, as a rule, on the last day or the day before the last of the initial paroxysm, and Obermeier has observed a sudden rise of four degrees in half an hour just before the crisis. Meschede,12 however, found the highest temperature on the corresponding days of the first relapse.

12 Loc. cit.

The duration of the primary paroxysm is usually six or seven days; but this is subject to considerable variations, as will be seen from the following table of 160 cases in which the duration was accurately ascertained: Initial paroxysm lasted—2 days in 1 case; 3 days in 2 cases; 4 days in 10 cases; 5 days in 19 cases; 6 days in 40 cases; 7 days in 58 cases; 8 days in 18 cases; 9 days in 2 cases; 10 days in 5 cases; 11 days in 2 cases; 14 days in 2 cases; 15 days in 1 case; and Parry, observing the same epidemic, found the duration of the first paroxysm to vary from 4 to 11 days. It is, however, rare for the duration to exceed ten days unless some complication be present.

FIG. 20.
Typical case of relapsing fever, with three relapses, terminating in recovery. (From Motschutkoffsky)

With the beginning of the crisis there is a prodigious and sudden fall of temperature, unequalled in any other condition of disease. Within a few hours it may fall six or eight degrees (going down at the rate of 1.5° or 2° an hour); and falls of 12°, 13°, or even 14.4° (Murchison), in the course of twelve hours have been noted. In our own cases the greatest fall was from 107.2° to 95°, or 12.2°; and this is as low a point as is usually reached, though temperatures of 94°, 93°, or even 92°, have repeatedly been observed. Murchison refers to one case in which collapse supervened, where the rectal temperature was 90.6°. In nearly all of our cases a subnormal temperature occurred at the crisis, and lasted for a day or two subsequently, when it gradually rose and remained normal until the relapse, unless some transient complication caused a temporary rise in the interval.

FIG. 21.
Typical case of relapsing fever (Mary Collins, aged 32), terminating in recovery. One relapse, with slight post-critical rise of temperature.