7 Medical Times, March 22, 1851.
8 A Treatise on the Practice of Medicine, Philadelphia, 1855.
9 A Treatise on the Principles and Practice of Medicine, Philadelphia, 1868.
10 Ibid.
11 A Treatise on the Continued Fevers, New York, 1881.
Unquestionably, many cases which have been classed under the head of simple continued fever, are really mild or abortive cases of typhoid or typhus fever, in which, in consequence of partial protection on the part of the patient, the characteristic symptoms of these diseases have not been developed. Such cases are seen in numbers during epidemics of these diseases. But, making due allowance for this source of error, there yet remain many cases which cannot be thus explained. Moreover, the disease occurs at times when no such epidemics exist. It may, therefore, be safely assumed that there is such a fever, and that, consequently, it must be accorded full recognition.
CAUSES.—Any non-specific cause which is capable of producing a profound derangement of one or more of the important functions of the body may give rise to simple continued fever. It may follow, therefore, upon excesses of the table, extreme mental or bodily fatigue, exposure to the direct rays of the sun, or to great heat or cold, or upon the suppression of a secretion. One of its most frequent causes is over-exertion in warm weather. James C. Wilson has called attention to its frequent occurrence as a consequence of the combined influence of the excitement, the physical exhaustion, and the exposure to the direct rays of the mid-day sun which are attendant upon surf-bathing. It is often due in young children to the irritation involved in the process of teething or to that caused by the presence of worms in the alimentary canal. Wood taught that it might also sometimes occur during the prevalence of contagious diseases as an effect of the epidemic influence in those who were partially protected by a previous attack of the disease, or from some other cause, but it is more probable that cases arising under these circumstances are either mild cases of the prevalent disease or else are attributable to fatigue from nursing or to over-anxiety. The disease is more common in the young than in the old, and in children than in adults—probably from the greater impressionability of the nervous systems of the latter.
The causes of the ardent continued fever of the tropics, which is usually recognized as a form of simple continued fever, do not differ materially, except in degree, from those of the simpler forms of the disease; but exposure to the direct rays of the sun would seem to be especially prone to give rise to the disease in those who are unaccustomed to the heat of a tropical climate. Robust young Europeans lately arrived in a warm country are, it is said, peculiarly liable to suffer from it.12 It is most common in those parts of India which do not experience much of the benefit of the monsoon rains, and whose hot season is not tempered by regular breezes from the sea. It is hence more frequently met with in inland districts in which the temperature is high, but in which malaria-generating conditions are absent.
12 Morehead, Clinical Researches on Diseases in India, London, 1856; also Twining, Clinical Illustrations of the More Important Diseases of Bengal, Calcutta, 1835.
SYMPTOMS AND COURSE.—Simple continued fever occurs in this country only as a sporadic disease, and almost invariably ends in recovery; in tropical climates, however, it may prevail epidemically, and sometimes presents symptoms of a very grave character. In its mildest form it not infrequently runs its course in a few hours, and is rarely prolonged much beyond twenty-four, and is hence called ephemera. It then usually begins somewhat abruptly with a chill, but in a few instances this is preceded by feelings of languor and weariness. Febrile reaction is soon established, and is generally well marked; the pulse is quick and full, the temperature rises rapidly, and the face is flushed. The tongue is coated with a whitish fur, the urine is scanty and high-colored, and the bowels are constipated. Other symptoms are excessive thirst, headache, restlessness, and sleeplessness, or, on the other hand, a tendency to somnolence. Vomiting is not common except in those cases which follow upon an error of diet, but there is generally some nausea and anorexia. Muscular pains are also occasionally present, and may give rise to a good deal of distress. The subsidence of these symptoms is often quite as abrupt as their onset, the crisis being frequently marked by a copious perspiration.