This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
Chill, or repeated chilliness, followed by fever continuing till eruption appears; intense headache, and pain in the back; vomiting; tongue coated, and no appetite; offensive breath; sometimes scarlet rash on abdomen and inside of thighs; sleeplessness, sometimes delirium; at the end of the second to fourth day, eruption of small red pimples beginning on the face, neck, and wrists, then extending to the trunk and lower extremities; attended by severe burning and itching; mucous membrane of mouth and throat also show the eruption; sore throat; fever, pain in the back and nausea subside when eruption appears; the spots enlarge, and about the eighth day become filled with matter, and center becomes depressed; skin now much swollen; fever rises again; after three or four days the pustules begin to dry, and in two or three days are covered with brown scabs, which gradually loosen; severe itching.
This is one of the most dreaded of all infectious diseases. This is partly owing to the fact that it is one of the most contagious of all diseases of this class. The symptoms generally appear from ten days to two weeks after exposure. The characteristic features of the eruption are at first a shot-like feeling presented to the finger by the small rod spots which appear first upon the back, breast, and arms, gradually extending to the whole body. On the second day, the points become enlarged and elevated, forming dark red papules. By the third day, they become still further enlarged and filled with a milky fluid forming vesicles, which continue to enlarge for four or five days longer, becoming conical and as large as a pea. The point of the cone now becomes depressed, so that the vesicle shows a little hollow in the center and is said to be umbilicated. The fluid contained in them becomes thick and yel low. This is termed the suppurative stage, which is attended by a return of the fever which generally almost entirely subsides on the appearance of the eruption. Sometimes the vesicles run together, forming large spots, when the disease is said to be confluent. This is the worst form of the disease. After recovery, most patients present a larger or smaller number of slight depressions in the skin known as pock-marks, due to the eruption.
In the mild form of the disease known as varioloid, the fever is much less intense, the eruption generally less profuse, and the vesicles do not matterate or become pustules. In the severe form of the disease pneumonia, bronchitis, dysentery, and hemorrhage, are likely to occur in connection with the second fever, and are frequently the cause of death.
Small-pox has been known as a dreaded disease for more than a thousand years, during which time it has frequently raged with great severity in various countries. During the Middle Ages it must have been very common to have given rise to the proverb current at that time, "From small-pox and love, but few remain free."