Generally on the third or lourth day ot the disease the temperature falls to normal and there appears a variable rash. With this begins the second stage of the disease. The rash appears principally on the face, the hands, forearms, and chest; occasionally it spreads over the entire body. It is most frequently described as a scarlatiniform, measly, erysipelatous rash, or as urticaria. A lichen like exan them simulating the papular syphilid, an erythema papulatum multiforme, is also described. Petechia? and formation of furuncles are rarely seen (Narich in Smyrna).
In this stage there is not infrequently swelling of the lymphatic glands, particularly those of the neck and groin region (de Brun, von During, Narich). Orchitis also is mentioned, and troublesome salivation and parotitis. The rash is often very evanescent, and disappears within a few or after twenty four hours. In the majority of cases it lasts from two to three days, seldom longer-only exceptionally until the fourteenth day. Occasionally there is a recurrence, particularly on the sixth day, when the rash may reappear as a "miniature edition" of the first (von During).
Toward the termination of the rash there arises an extremely intense itching of the skin. This pruritus, with desquamation of the skin, is mentioned by all as a characteristic and very troublesome sequel of dengue. It frequently lasts until the third week, and renders the convalescence more difficult by giving rise to insomnia.
The rash is almost unanimously considered a pathognomonic manifestation of dengue. Kartulis found it constantly, von During in nine tenths of the cases, and Charles and Martialis in two thirds of the cases. De Brun and the Smyrna medical report say that in exceptional cases the rash may be absent. Morgan asserts that he saw it in only 11 per cent, of the cases. Floras (Constantinople), although he observed in 60 cases the initial cutaneous erythema, the so called primary rash on the face, on the arms, and trunk, never saw "a completely developed eruption." This may have been a matter of chance. Many secondary exanthemata are of a fleeting nature and easily overlooked (Sandwith), and occasionally recognized only by the succeeding desquamation and pruritus. Many "mild cases," as related by de Brun, "were led to seek medical aid only during the second stage of the disease, by the appearance of the eruption or even after its termination, by the violent itching of the skin."
There is no unanimity of opinion regarding the fever in the stadium exanthematis. Many writers emphasize the afebrile stage of the disease at this time; hence the designation, "afebrile" stage. De Brun says: "In some patients the fever declines or disappears at once at the outbreak of the secondary rash; in others, the fever continues or even increases at the occurrence of the eruption." Narich and other Smyrna physicians emphasize the fact that with the appearance of the rash a renewed outbreak of the fever occurs. Von During supports this view, especially in regard to rash recurrences, but at the same time, like de Brun, states that the fever of the first stage falls to normal on the fourth day, with the appearance of the eruption. During the exanthematous stage, according to von During, there exists "increased normal temperature" or what is otherwise called "subfebrile temperature."