The Pains.—Very marked soreness deeply seated about the place of origin of the ocular muscles so that every movement of the eyeballs is at once complained of as giving pain.
General pains all over the body, more especially of the back and about tendinous insertions of the muscles which cause the pains to be referred to the joints. The knee-joint pains are probably the most frequent. The rachialgia may be as great as that in variola or yellow fever.
The Eruption.—The characteristic eruption does not appear until about the time of the intermission or with the accession of the terminal fever.
The fall of fever about the third or fourth day is often attended by a critical epistaxis, sweat or diarrhoea, to be succeeded by an intermission of from one to three days of a feeling of well-being. About this time or with the secondary rise of fever the true dengue rash appears. It is at first noted about the bases of the thumbs and extending over the dorsal surfaces of the wrists. Almost simultaneously a measles-like rash appears over the dorsal and internal surfaces of the big toe extending to the ankle, especially over the internal malleolus. Later on the elbows and knees may be involved or the rash may cover thickly the entire body. A carmine flush of the palms of the hands and soles of the feet is not uncommon. A furfuraceous desquamation with much itching at times follows the eruption. The so-called primary eruption is nothing more than an initial flushing of the face, it is ephemeral. The true dengue rash may also be quite ephemeral but usually it lasts for two or three days, or possibly four or five days.
The Nervous System.—Besides the headaches we have insomnia and depression which extends through convalescence. Apathy is marked.
The Blood.—This shows a leucopenia of about 4000 from shortly after the onset together with a reduction of the percentage of polymorphonuclears to about 45%. During the attack the eosinophiles are decreased but there is an increase during convalescence.
Diagnosis
The two diseases with which dengue can be most easily confused are influenza and yellow fever. In fact when the great pandemic of influenza (1890) first made its appearance in France, many regarded it as an atypical form of dengue.
CLINICAL CHART
ONE HUNDRED CASES OF DENGUE FEVER