Delirium is not unusual during the fever. Among children attacks are often ushered in by convulsions. In such cases delirium may be persistent and alarming in violence.
The pulse in the early stage of yellow fever is slower in proportion to the temperature than in most other acute diseases. This is more especially true in respect to mild cases. Another characteristic feature of the pulse in yellow fever is that it declines in frequency before the fever has reached its maximum. In the mildest forms of the disease the temperature will attain its highest record within twelve hours. It then rapidly defervesces, never to return again. But in some cases of a moderately mild form the body heat does not reach its acme of intensity until the second day, occasionally not until the third or fourth day. In these cases also the pulse is apt to decline in frequency before the fever has culminated. There are therefore no fixed laws which govern the duration of the hot stage of yellow fever. Those which relate to the pulse are more uniform.
The following clinical reports of two cases support this statement. The detailed account of the symptoms establishing their diagnosis as mild cases of yellow fever is omitted.
Susie W——, white, aged seventeen years, was admitted to Charity Hospital on August 28, 1878. First observation, nine hours after the beginning of the attack, pulse 100, temperature 104.6°. Morning of 29th, pulse 94, temperature 102.8°; evening, pulse 80, temperature 101.5°. Sanguineous discharge from vagina began on 29th; patient supposed it to be her proper period. Aug. 30th, pulse 80, temperature 99.2°; convalescent and dismissed from further observations. In this case the urine presented a trace of albumen early on the second day, but as the menses appeared shortly after the urine was obtained, the presence of albumen may be in that manner accounted for.
Bessie L——, white, age twenty-seven years, admitted to Charity Hospital on August 28, 1878. First observation, twelve hours after beginning of attack, pulse 100, temperature 100.6°. 29th, pulse 76, temperature 102.3°. 30th, pulse 64, temperature 101.5°. Sanguineous discharge from vagina began on 30th and continued until Sept. 4th; this was two weeks before the patient's regular period. The urine showed traces of albumen at date of admission. Discharged, cured, Aug. 31st.
It may also be stated of the pulse of yellow fever that it is easily compressible and often gaseous in character.
Perspiration is probably an incident in the natural clinical history of a case of yellow fever. It occurs spontaneously if the patient's surface is protected from those influences which conflict with its appearance. It is not critical in any sense of the word, and may coexist with high temperature.
Yellow fever is considered to have two clinical stages. The first is the paroxysm. This is made to include the cold stage and succeeding fever. The cold stage is often almost or quite inappreciable, and when this is not the fact it is in simple cases a very unimportant event. It is therefore quite convenient to include it with the fever under the term paroxysm. The paroxysm of a simple case is terminated by a subsidence of the fever to nearly or quite a normal temperature. Sometimes the temperature falls below the normal standard.
The neuralgias and subjective sufferings are greatly mitigated or cease altogether. Thirst and restlessness are relieved, and the patient sees before him a delicious, but too often treacherous, mirage of restoration to perfect health. This is termed the stage of calm, perhaps because it often precedes a tempest of fatal symptoms.
In mild cases convalescence begins at the termination of the paroxysm, and may proceed without interruption until complete re-establishment of health has been accomplished. But in the very mildest cases the process of recovery is easily interrupted.